xref: /open-nvidia-gpu/kernel-open/nvidia-uvm/uvm.h (revision 4397463e)

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//
// uvm.h
//
// This file contains the UVM API declarations, for the userspace-to-kernel
// calls. For legacy API definitions that are in use on Windows, see
// uvm_legacy.h.
//

// UVM API signature modification steps
// In order to change API signature for any of the APIs defined in this file, a
// particular sequence of steps has to be followed since the consumer of this
// API (i.e. CUDA) belongs to a different module branch than the one for this
// file. Here are the steps to change the signature for a hypothetical API named
// UvmExampleApi. The assumption being made here is that this file is being
// modified in chips_a.
// 1) Increment the value of UVM_API_LATEST_REVISION defined in this file.
// 2) Use the macro UVM_API_REV_IS_AT_MOST to define the two revisions of the
//    API as follows:
//     #if UVM_API_REV_IS_AT_MOST(<previous_value_of_UVM_API_LATEST_REVISION>)
//     // Old UvmExampleApi declaration
//     #else
//     // New UvmExampleApi declaration
//     #endif
// 3) Do the same thing for the function definition, and for any structs that
//    are taken as arguments to these functions.
// 4) Let this change propagate over to cuda_a, so that the CUDA driver can
//    start using the new API by bumping up the API version number its using.
//    This can be found in gpgpu/cuda/cuda.nvmk.
// 5) Once the cuda_a changes have made it back into chips_a, remove the old API
//    declaration, definition, and any old structs that were in use.

#ifndef _UVM_H_
#define _UVM_H_

#define UVM_API_LATEST_REVISION 7

#if !defined(UVM_API_REVISION)
#error "please define UVM_API_REVISION macro to a desired version number or UVM_API_LATEST_REVISION macro"
#endif

#define UVM_API_REV_IS_AT_MOST(rev) (UVM_API_REVISION <= rev)

#include "uvm_types.h"
#include "uvm_user_types.h"
#include "uvm_legacy.h"

#ifdef __cplusplus
extern "C" {
#endif

//------------------------------------------------------------------------------
// UvmSetDriverVersion
//
// Informs the user-mode layer which kernel driver version is running. The user-
// mode layer uses this information to know what flavor to use when calling
// kernel APIs.
//
// If this API is not called, the user-mode layer assumes that the kernel
// version is the same as the user-mode layer version.
//
// The last UvmDeinitialize will reset this state.
//
// If this API is called, it must be called before UvmInitialize. It is an error
// to call this API after UvmInitialize and before the last UvmDeinitialize, or
// to call this API more than once before the last UvmDeinitialize.
//
// Arguments:
//     major: (INPUT)
//         The kernel driver's major version number, such as 384.
//
//     changelist: (INPUT)
//         The changelist at which the kernel driver was built.
//
// Error codes:
//     NV_ERR_INVALID_STATE:
//         UvmInitialize or UvmSetDriverVersion has already been called.
//
//------------------------------------------------------------------------------
NV_STATUS UvmSetDriverVersion(NvU32 major, NvU32 changelist);

//------------------------------------------------------------------------------
// UvmInitialize
//
// This must be called before any other UVM functions except for
// UvmSetDriverVersion. Repeated calls to UvmInitialize increment a refcount,
// which is decremented by calls to UvmDeinitialize. UVM deinitilization occurs
// when the refcount reaches zero.
//
// The UVM file descriptor passed in can either be UVM_AUTO_FD or a valid file
// descriptor created during a prior call to UvmInitialize. If UVM_AUTO_FD is
// passed and the refcount is zero, a new file descriptor is created. Subsequent
// calls must either also specify UVM_AUTO_FD or use the current file
// descriptor. If the first call to UvmInitialize did not specify UVM_AUTO_FD,
// all subsequent calls must use the same file descriptor used in the initial
// call. The file descriptor that is currently in use can be retrieved using
// UvmGetFileDescriptor.
//
// If flags does not contain UVM_INIT_FLAGS_MULTI_PROCESS_SHARING_MODE, the
// UvmInitialize call which creates the file descriptor will associate the
// calling process with that file descriptor when the Operating System can
// support such an association. In that case UvmInitialize may be called using
// the same file in other processes, but internally the file remains associated
// with the original process.
//
// Arguments:
//     fd: (INPUT)
//         The UVM file descriptor to initialize UVM with. Passing in
//         UVM_AUTO_FD creates a new file descriptor on the first call to
//         UvmInitialize.
//
//     flags: (INPUT)
//         Must be a combination of 0 or more of following flags:
//
//         - UVM_INIT_FLAGS_DISABLE_HMM
//             Specifying this flag will only have an effect if the system
//             allows GPUs to read/write system (CPU) pageable memory and the
//             GPUs do not have hardware support to do it transparently, and the
//             UVM_INIT_FLAGS_MULTI_PROCESS_SHARING_MODE flag is not specified.
//             In such cases pageable access from the GPU will be disabled.
//
//             Pageable memory here refers to memory allocated by the Operating
//             System for the process's globals, stack variables, heap
//             allocations, etc. that has not been registered for CUDA access
//             using cudaHostRegister.
//
//         - UVM_INIT_FLAGS_MULTI_PROCESS_SHARING_MODE
//             Specifying this flag will prevent UVM from creating any
//             association between this process and the UVM file descriptor.
//             Pageable memory access of any kind will be disabled (regardless
//             of whether UVM_INIT_FLAGS_DISABLE_HMM was specified) and the GPU
//             resources used by the UVM file descriptor will be freed when the
//             last reference to the file is dropped rather than when this
//             process exits.
//
//             If this flag is not specified, calling UvmMemMap or
//             UvmAllocSemaphorePool on the same file from a different process
//             may return an error.
//
//         If UvmInitialize is called multiple times on the same file, even from
//         different processes, the flags to each call must match.
//
// Error codes:
//     NV_ERR_NOT_SUPPORTED:
//         The Linux kernel is not able to support UVM. This could be because
//         the kernel is too old, or because it lacks a feature that UVM
//         requires. The kernel log will have details.
//
//     NV_ERR_INVALID_ARGUMENT:
//         The file descriptor passed in is neither UVM_AUTO_FD nor a valid file
//         descriptor created during a prior call to UvmInitialize, or the flags
//         do not match a prior call to UvmInitialize.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
#if UVM_API_REV_IS_AT_MOST(4)
NV_STATUS UvmInitialize(UvmFileDescriptor fd);
#else
NV_STATUS UvmInitialize(UvmFileDescriptor fd,
                        NvU64             flags);
#endif

//------------------------------------------------------------------------------
// UvmDeinitialize
//
// Releases the reference implicitly obtained by UvmInitialize. If the refcount
// reaches zero, cleans up all UVM resources associated with the calling
// process. Any channels that are still registered will be unregistered prior to
// unmapping any managed allocations. Any resources that have been shared with
// other processes and are still being used will continue to remain valid.
//
// Error codes:
//     NV_ERR_INVALID_STATE:
//         Refcount is zero.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDeinitialize(void);

//------------------------------------------------------------------------------
// UvmReopen
//
// Reinitializes the UVM driver after checking for minimal user-mode state.
// Before calling this function, all GPUs must be unregistered with
// UvmUnregisterGpu() and all allocated VA ranges must be freed with UvmFree().
// Note that it is not required to release VA ranges that were reserved with
// UvmReserveVa().
//
// UvmReopen() closes the open file returned by UvmGetFileDescriptor() and
// replaces it with a new open file with the same name.
//
// Arguments:
//     flags: (INPUT)
//         Must be zero.  UVM will be reinitialized with the
//         Same flags that were passed to UvmInitialize() originally.
//
// Error codes:
//     NV_ERR_INVALID_STATE:
//         UVM was not initialized before calling this function.
//
//     NV_ERR_UVM_ADDRESS_IN_USE:
//         Not all allocated VA ranges were freed before calling this function.
//
//     NV_ERR_IN_USE:
//         Not all GPUs were unregistered before calling this function.
//
//     NV_ERR_INVALID_FLAGS:
//         Flags is not zero.
//
//     NV_ERR_OPERATING_SYSTEM:
//         Replacing the original UVM file descriptor failed.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmReopen(NvU64 flags);

//------------------------------------------------------------------------------
// UvmIsPageableMemoryAccessSupported
//
// Returns true only if pageable memory access from GPUs is supported by the
// system and that support was not explicitly disabled via UvmInitialize.
//
// Pageable memory here refers to memory allocated by the Operating System for
// the process's globals, stack variables, heap allocations, etc that has not
// been registered for CUDA access using cudaHostRegister.
//
// Note that this does not check whether GPUs are present which can make use of
// this feature, just whether system support exists. If
// UvmIsPageableMemoryAccessSupported reports that pageable memory access is
// supported, UvmIsPageableMemoryAccessSupportedOnGpu can be used for querying
// per-GPU support.
//
// Arguments:
//     pageableMemAccess: (OUTPUT)
//         Returns true (non-zero) if the system supports pageable memory access
//         from GPUs and that support was not explicitly disabled via
//         UvmInitialize, and false (zero) otherwise.
//
// Error codes:
//     NV_ERR_INVALID_STATE:
//         UVM was not initialized.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmIsPageableMemoryAccessSupported(NvBool *pageableMemAccess);

//------------------------------------------------------------------------------
// UvmIsPageableMemoryAccessSupportedOnGpu
//
// Returns whether pageable memory access is supported from the given GPU on
// this system and that support was not explicitly disabled via UvmInitialize.
// The GPU must have been previously registered with UvmRegisterGpu first.
//
// Pageable memory here refers to memory allocated by the Operating System for
// the process's globals, stack variables, heap allocations, etc that has not
// been registered for CUDA access using cudaHostRegister.
//
// Arguments:
//     gpuUuid: (INPUT)
//         UUID of the GPU for which pageable memory access support is queried.
//
//     pageableMemAccess: (OUTPUT)
//         Returns true (non-zero) if the GPU represented by gpuUuid supports
//         pageable memory access and that support was not explicitly disabled
//         via UvmInitialize, and false (zero) otherwise.
//
// Error codes:
//     NV_ERR_INVALID_STATE:
//         UVM was not initialized.
//
//     NV_ERR_INVALID_DEVICE:
//         The given GPU has not been registered.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmIsPageableMemoryAccessSupportedOnGpu(const NvProcessorUuid *gpuUuid,
                                                  NvBool *pageableMemAccess);

//------------------------------------------------------------------------------
// UvmRegisterGpu
//
// Registers a GPU with UVM. If this is the first process to register this GPU,
// the UVM driver initializes resources on the GPU and prepares it for CUDA
// usage. Calling UvmRegisterGpu multiple times on the same GPU from the same
// process results in an error.
//
// Arguments:
//     gpuUuid: (INPUT)
//         UUID of the GPU to register.
//
// Error codes:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_INSUFFICIENT_RESOURCES
//         Internal client or object allocation failed.
//
//     NV_ERR_INVALID_DEVICE:
//         The GPU referred to by pGpuUuid has already been registered by this
//         process.
//
//         The GPU referred to by pGpuUuid doesn't have a NVLINK2 link to the
//         CPU but a GPU with such a link has already been registered by this
//         process, or vice-versa.
//
//     NV_ERR_NOT_SUPPORTED:
//         The GPU referred to by pGpuUuid is not supported by UVM or the GPU
//         is configured to run in virtualization mode without SRIOV support.
//
//     NV_ERR_GPU_UUID_NOT_FOUND:
//         The GPU referred to by pGpuUuid was not found.
//
//     NV_ERR_PAGE_TABLE_NOT_AVAIL:
//         The system requires that the UVM file descriptor be associated with a
//         single process, and that process has exited.
//
//     NV_ERR_INVALID_ARGUMENT:
//         OS state required to register the GPU is not present.
//
//     NV_ERR_OBJECT_NOT_FOUND:
//         OS state required to register the GPU is not present.
//
//     NV_ERR_INVALID_STATE:
//         OS state required to register the GPU is malformed.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmRegisterGpu(const NvProcessorUuid *gpuUuid);

//------------------------------------------------------------------------------
// UvmRegisterGpuSmc
//
// The same as UvmRegisterGpu, but takes additional parameters to specify the
// GPU partition being registered if SMC is enabled.
//
// TODO: Bug 2844714: Merge UvmRegisterGpuSmc() with UvmRegisterGpu() once
//       the initial SMC support is in place.
//
// Arguments:
//     gpuUuid: (INPUT)
//         UUID of the parent GPU of the SMC partition to register.
//
//     platformParams: (INPUT)
//         User handles identifying the partition to register.
//
// Error codes (see UvmRegisterGpu also):
//
//     NV_ERR_INVALID_STATE:
//         SMC was not enabled, or the partition identified by the user
//         handles or its configuration changed.
//
NV_STATUS UvmRegisterGpuSmc(const NvProcessorUuid *gpuUuid,
                            const UvmGpuPlatformParams *platformParams);

//------------------------------------------------------------------------------
// UvmUnregisterGpu
//
// Unregisters a GPU from UVM. If this is the last process to unregister this
// GPU, the UVM driver frees all resources allocated on the GPU when the GPU
// was first registered. Any pages on the GPU allocated by the UVM driver will
// be migrated to CPU memory before the GPU resources are freed.
//
// Any GPU VA spaces or channels that were registered on this GPU using
// UvmRegisterGpuVaSpace or UvmRegisterChannel respectively, will be
// unregistered. Any state that was set by calling UvmSetPreferredLocation or
// UvmSetAccessedBy for this GPU will be cleared. Any pages that were associated
// with a non-migratable range group and had this GPU as their preferred
// location will have their range group association changed to
// UVM_RANGE_GROUP_ID_NONE.
//
// Arguments:
//     gpuUuid: (INPUT)
//         UUID of the GPU to unregister.
//
// Error codes:
//     NV_ERR_INVALID_DEVICE:
//         The GPU referred to by pGpuUuid was not registered by this process.
//
//     NV_ERR_GPU_UUID_NOT_FOUND:
//         The GPU referred to by pGpuUuid was not found.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmUnregisterGpu(const NvProcessorUuid *gpuUuid);

//------------------------------------------------------------------------------
// UvmRegisterGpuVaSpace
//
// Registers a GPU's VA (virtual address) space for use with UVM. Only one GPU
// VA space can be registered for a given GPU at a time. Once a VA space has
// been registered for a GPU, all page table updates for that VA space on that
// GPU will be managed by the UVM driver.
//
// The GPU must have been registered using UvmRegisterGpu prior to making this
// call.
//
// On systems with GPUs that support transparent access to pageable memory, this
// feature is enabled per GPU VA space. This setting must match for all
// registered GPU VA spaces.
//
// Any VA ranges that were allocated using UvmAllocSemaphorePool will be mapped
// on this GPU with the mapping and caching attributes as specified during that
// call, or with default attributes if none were specified.
//
// Any VA ranges that had a preferred location set to this GPU will be mapped on
// this GPU only if this GPU is not fault-capable and the VA range belongs to a
// non-migratable range group. If such a mapping cannot be established, an error
// is returned.
//
// Any VA ranges which have accessed-by set for this GPU will be mapped on this
// GPU. If that VA range resides in a PCIe peer GPU's memory and P2P support
// between the two GPUs has not been enabled via UvmEnablePeerAccess, then a
// mapping won't be established. Also, if read duplication is enabled for this
// VA range, or its preferred location is set to this GPU, and this GPU is a
// fault-capable GPU, then a mapping will not be established.  If this is a
// non-fault-capable GPU and a mapping cannot be established, then an error is
// returned.
//
// If P2P support has been enabled between this GPU and another GPU that also
// has a GPU VA space registered, then the two GPU VA spaces must support the
// same set of page sizes for GPU mappings. Otherwise, an error is returned.
//
// Note that all the aforementioned VA ranges must lie within the largest
// possible virtual address supported by this GPU.
//
// Arguments:
//     gpuUuid: (INPUT)
//         UUID of the GPU to register.
//
//     platformParams: (INPUT)
//         On Linux: RM ctrl fd, hClient and hVaSpace.
//
// Error codes:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_OUT_OF_RANGE:
//         A VA range that needs to be mapped on this GPU exceeds the largest
//         virtual address supported by the GPU.
//
//     NV_ERR_INVALID_DEVICE:
//         The GPU referred to by gpuUuid was not registered or a VA space has
//         already been registered for this GPU. Or this is a non-fault-capable
//         GPU that is present in the accessed-by list of a VA range that
//         resides on another non-fault-capable GPU, and P2P support between
//         both GPUs is not enabled.
//
//     NV_ERR_OTHER_DEVICE_FOUND:
//         The UUID does not match the UUID of the device that is associated
//         with the VA space handles in the platformParams argument.
//
//     NV_ERR_INVALID_FLAGS:
//         The VA space was originally allocated with UVM-incompatible flags.
//         This includes the case in which the value for the setting to enable
//         transparent access to pageable memory for the given GPU VA space does
//         not match the value in previously-registered GPU VA spaces, or that
//         value is set but pageable memory access has been disabled via
//         UvmInitialize.
//
//     NV_ERR_NOT_COMPATIBLE:
//         The GPU referred to by gpuUuid has P2P support enabled with another
//         GPU and the set of page sizes supported by the specified VA space
//         doesn't match that of the VA space registered on the peer GPU.
//
//     NV_ERR_INVALID_ARGUMENT:
//         Some problem with the platform specific arguments was detected.
//
//     NV_ERR_NOT_SUPPORTED:
//         A GPU VA space has already been registered using a different UVM file
//         descriptor in this process and this platform does not support that
//         operation, or a GPU VA space has already been registered on this UVM
//         file descriptor by a different process and this platform does not
//         support that operation.
//
//     NV_ERR_PAGE_TABLE_NOT_AVAIL:
//         The system requires that the UVM file descriptor be associated with a
//         single process, and that process has exited.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmRegisterGpuVaSpace(const NvProcessorUuid             *gpuUuid,
                                const UvmGpuVaSpacePlatformParams *platformParams);

//------------------------------------------------------------------------------
// UvmUnregisterGpuVaSpace
//
// Unregisters the GPU VA space that was previously registered via a call to
// UvmRegisterGpuVaSpace.
//
// Any page table mappings created by UVM on that GPU for that VA space will be
// unmapped. Any channels that were registered on this GPU using
// UvmRegisterChannel will be unregistered.
//
// Arguments:
//     gpuUuid: (INPUT)
//         UUID of the GPU whose VA space should be unregistered.
//
// Error codes:
//     NV_ERR_INVALID_DEVICE:
//         The GPU referred to by gpuUuid was not registered or no VA space has
//         been registered for this GPU.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmUnregisterGpuVaSpace(const NvProcessorUuid *gpuUuid);

//------------------------------------------------------------------------------
// UvmEnablePeerAccess
//
// Enables P2P (peer to peer) support in the UVM driver between two GPUs
// connected via PCIe. NVLink peers are automatically discovered/enabled in the
// driver at UvmRegisterGpu time. Enabling P2P support between two GPUs allows
// peer mappings to be created as part of fault servicing, memory allocation,
// etc. The P2P support is bidirectional i.e. enabling P2P between GPU A and
// GPU B also enables P2P support between GPU B and GPU A.
//
// The two GPUs must have been registered via UvmRegisterGpu prior to making
// this call. An error is returned if P2P support has already been enabled
// between these two GPUs in this process.
//
// The two GPUs must be connected via PCIe. An error is returned if the GPUs are
// not connected or are connected over an interconnect different than PCIe
// (NVLink, for example).
//
// If both GPUs have GPU VA spaces registered for them, the two GPU VA spaces
// must support the same set of page sizes for GPU mappings.
//
// If any VA range resides in one GPU's memory, and the peer GPU is in the
// accessed-by list of that VA range, then a peer mapping will be established
// unless the VA space for the peer GPU has not been registered, or read
// duplication is enabled for the VA range, or the preferred location of the VA
// range is the peer GPU.
//
// Arguments:
//     gpuUuidA: (INPUT)
//         UUID of GPU A.
//
//     gpuUuidB: (INPUT)
//         UUID of GPU B.
//
// Error codes:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_INVALID_DEVICE:
//         At least one GPU has not been registered, P2P support has already
//         been enabled between the two GPUs, or the GPUs are connected via an
//         interconnect other than PCIe.
//
//     NV_ERR_NOT_SUPPORTED:
//         The two GPUs are not peer capable.
//
//     NV_ERR_NOT_COMPATIBLE:
//         Both GPUs have a GPU VA space registered for them and the two VA
//         spaces don't support the same set of page sizes for GPU mappings.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEnablePeerAccess(const NvProcessorUuid *gpuUuidA,
                              const NvProcessorUuid *gpuUuidB);

//------------------------------------------------------------------------------
// UvmDisablePeerAccess
//
// Disables P2P (peer to peer) support in the UVM driver between two GPUs.
// connected via PCIe. NVLink peers are automatically disabled in the driver
// at UvmUnregisterGpu time. Disabling P2P support between two GPUs removes all
// existing peer mappings from either GPU to the other, and also prevents new
// peer mappings from being established between the two GPUs.
//
// The two GPUs must be connected via PCIe. An error is returned if the GPUs are
// not connected or are connected over an interconnect different than PCIe
// (NVLink, for example).
//
// If one of the two GPUs is present in the accessed-by list of a non-migratable
// VA range that has a preferred location set to the other GPU, and the two GPUs
// are not fault-capable, then the GPU is removed from the accessed-by list of
// the range.
//
// Arguments:
//     gpuUuidA: (INPUT)
//         UUID of GPU A.
//
//     gpuUuidB: (INPUT)
//         UUID of GPU B.
//
// Error codes:
//     NV_ERR_INVALID_DEVICE:
//         At least one GPU has not been registered, or P2P support has not been
//         enabled between the two GPUs, or the GPUs are connected via an
//         interconnect other than PCIe.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDisablePeerAccess(const NvProcessorUuid *gpuUuidA,
                               const NvProcessorUuid *gpuUuidB);

//------------------------------------------------------------------------------
// UvmRegisterChannel
//
// Register a channel for use with UVM. Any faults that occur on this channel
// will be handled by the UVM driver.
//
// A GPU VA space must have been registered on this GPU via
// UvmRegisterGpuVaSpace prior to making this call.
//
// For channels that require associated mappings, the base and length of a
// virtual address region that was reserved via UvmReserveVa must be supplied to
// this call in order to map those allocations. The size and alignment of this
// region can be obtained by calling the appropriate platform specific API. For
// example, on RM, an RM control call has to be made with the control type as
// NV2080_CTRL_CMD_GR_GET_CTX_BUFFER_SIZE. If no region needs to be reserved for
// this channel, the base and length arguments are ignored.
//
// Using the same VA region for multiple UvmRegisterChannel calls is allowed,
// provided all allocations required by all of those calls fit within the
// region.
//
// Registering the same channel on multiple subdevices of an SLI group is
// disallowed.
//
// On any errors, the channel may be reset, thereby terminating any pending
// work on that channel.
//
// Arguments:
//     gpuUuid: (INPUT)
//        UUID of the GPU that the channel is associated with.
//
//     platformParams: (INPUT)
//         On Linux: RM ctrl fd, hClient and hChannel.
//
//     base: (INPUT)
//         Base address (starting point) of the VA (virtual address) range
//         reserved for mapping the allocations associated with this channel.
//         If this channel does not have associated allocations, this argument
//         is ignored.
//
//     length: (INPUT)
//         Length, in bytes, of the range. If this channel does not have
//         associated allocations, this argument is ignored.
//
// Error codes:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_OTHER_DEVICE_FOUND:
//         The UUID does not match the UUID of the device that is associated
//         with the channel identifier in the platformParams argument.
//
//     NV_ERR_GPU_INVALID_DEVICE:
//         The GPU referred to by pGpuUuid was not registered or no VA space
//         has been registered for this GPU.
//
//     NV_ERR_INVALID_CHANNEL:
//         The given channel identifier is invalid or has already been
//         registered.
//
//     NV_ERR_INVALID_ADDRESS:
//         The channel has allocations which need to be mapped but the base
//         address is invalid, or the VA range specified by base and length
//         is too small.
//
//     NV_ERR_INVALID_ARGUMENT:
//         Either some problem with the platform-specific arguments was detected
//         or the channel has allocations which need to be mapped but length is
//         invalid.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmRegisterChannel(const NvProcessorUuid          *gpuUuid,
                             const UvmChannelPlatformParams *platformParams,
                             void                           *base,
                             NvLength                        length);

//------------------------------------------------------------------------------
// UvmUnregisterChannel
//
// Unregisters a channel from UVM. The channel must have been previously
// registered via a call to UvmRegisterChannel. The channel will be reset,
// thereby terminating any pending work on that channel.
//
// Since channels may share virtual mappings, a call to UvmUnregisterChannel is
// not guaranteed to unmap the VA range passed into the corresponding
// UvmRegisterChannel call because other still-registered channels may be using
// allocations in that VA range. Only channels which share the same TSG can
// share allocations, so a channel's VA range can only be considered released
// after UvmUnregisterChannel has been called on all channels under that TSG.
//
// Arguments:
//     platformParams: (INPUT)
//         On Linux: RM ctrl fd, hClient and hChannel.
//
// Error codes:
//     NV_ERR_INVALID_CHANNEL:
//         The given channel identifier was not registered.
//
//     NV_ERR_INVALID_ARGUMENT:
//         Some problem with the platform specific arguments was detected.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmUnregisterChannel(const UvmChannelPlatformParams *platformParams);

//------------------------------------------------------------------------------
// UvmReserveVa
//
// Reserves VA space on the CPU for future use. Multiple, non-contiguous VA
// ranges can be reserved via this API.
//
// The starting address for the VA reservation can be either explicitly
// specified or left NULL to let the API implementation select one. When the
// starting address is specified, it must be aligned to the smallest CPU page
// size. When the starting address is not specified, the bounds of the search
// space within which the VA range should be reserved must be specified. The
// specified lower bound of the search space is rounded up to the nearest
// non-zero multiple of the requested alignment. The total size of the search
// space taking into consideration the rounded up lower bound cannot be less
// than the requested length for the VA reservation. The starting address chosen
// by the API implementation is guaranteed to be aligned to the requested
// alignment.
//
// The requested alignment must be either a power of two that is at least the
// smallest CPU page size or left zero to indicate default alignment which is
// the smallest CPU page size.
//
// The length of the VA reservation must be a multiple of the smallest CPU page
// size.
//
// Arguments:
//     base: (INPUT/OUTPUT)
//         Contains the starting address of the VA reservation when the call
//         returns successfully. If *base is NULL when this API is invoked, a VA
//         range that falls within the requested bounds is reserved. Note that
//         the lower bound will be rounded up to the nearest non-zero multiple
//         of the requested alignment. If *base is non-NULL when this API
//         is invoked, then that address is chosen as the starting address of
//         the VA reservation.
//
//     length: (INPUT)
//         Length in bytes of the region. Must be a multiple of the smallest CPU
//         page size.
//
//     minVa: (INPUT)
//         Lower limit for the search space within which the VA range must be
//         reserved. Will be rounded up to the nearest non-zero multiple of the
//         requested alignment. Ignored if *base is non-NULL when the API is
//         invoked.
//
//     maxVa: (INPUT)
//         Upper limit for the search space within which the VA range must be
//         reserved. Ignored if *base is non-NULL when the API is invoked.
//
//     alignment: (INPUT)
//         Alignment required for the starting address of the reservation. Must
//         either be zero to indicate default alignment which is smallest CPU
//         page size or a power of two that is at least the smallest CPU page
//         size. Ignored if *base is non-NULL when the API is invoked.
//
// Error codes:
//     NV_ERR_NO_MEMORY:
//         Either *base is NULL and no suitable VA reservation could be made or
//         some other internal memory allocation failed.
//
//     NV_ERR_UVM_ADDRESS_IN_USE:
//         *base is non-NULL and reserving the VA range at that address failed.
//
//     NV_ERR_INVALID_ADDRESS:
//         One of the following occurred:
//         - base is NULL.
//         - *base is non-NULL and is not aligned to the smallest CPU page size.
//         - *base is NULL and one of the following occurred:
//             - the rounded up minVa is not less than maxVa.
//             - the region covered by the rounded up minVa and maxVa is not big
//               enough to contain a VA reservation of the requested length.
//         - alignment is non-zero and is either not a power of two or is less
//           than the smallest CPU size.
//         - length is zero or is not a multiple of the smallest CPU page size.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmReserveVa(void     **base,
                       NvLength   length,
                       void      *minVa,
                       void      *maxVa,
                       NvLength   alignment);

//------------------------------------------------------------------------------
// UvmReleaseVa
//
// Releases all pages within the VA range. If any of the pages were committed,
// they are automatically decomitted as well.
//
// The release may encompass more than a single reserve VA or commit call, but
// must not partially release any regions that were either reserved or
// committed previously.
//
// Arguments:
//     base: (INPUT)
//         Base address (starting point) of the VA (virtual address) range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
// Error codes:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed. There is likely more than one
//         possible cause of this error.
//
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned or the range was not
//         previously reserved via UvmReserveVa.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmReleaseVa(void     *base,
                       NvLength  length);

//------------------------------------------------------------------------------
// UvmCreateRangeGroup
//
// Creates a new range group. Virtual address ranges can be associated with
// this range group as outlined in UvmSetRangeGroup.
//
// Arguments:
//     rangeGroupId: (OUTPUT)
//         Id of the newly created range group.
//
// Error codes:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_INVALID_ARGUMENT:
//         A NULL pointer was passed in the rangeGroupId argument.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmCreateRangeGroup(NvU64 *rangeGroupId);

//------------------------------------------------------------------------------
// UvmDestroyRangeGroup
//
// Destroys a previously created range group. If there are any pages associated
// with this range group, that association is cleared. i.e. the behavior is the
// same as associating those pages with UVM_RANGE_GROUP_ID_NONE via a call to
// UvmSetRangeGroup.
//
// Arguments:
//     rangeGroupId: (INPUT)
//         Id of the range group to be destroyed.
//
// Error codes:
//     NV_ERR_OBJECT_NOT_FOUND:
//         rangeGroupId was not created by a previous call to
//         UvmCreateRangeGroup.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDestroyRangeGroup(NvU64 rangeGroupId);

//------------------------------------------------------------------------------
// UvmSetRangeGroup
//
// Associates the pages in a virtual address (VA) range with the specified
// range group. The base address and length of the VA range must be aligned to
// the smallest page size supported by the CPU. If any pages in that VA range
// were associated with another range group, that association is changed to
// this range group. The VA range must have been allocated via either UvmAlloc
// or UvmMemMap.
//
// If the range group was made non-migratable by a previous call to
// UvmPreventMigrationRangeGroups, then all pages in the VA range are migrated
// to their preferred location if they are not already located there. If any
// page does not have a preferred location or if the preferred location is a
// fault-capable GPU, an error is returned.
//
// If rangeGroupId is UVM_RANGE_GROUP_ID_NONE, then all pages in the VA range
// will have their range group association removed.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     rangeGroupId: (INPUT)
//         Id of the range group to associate the VA range with.
//
// Errors:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned or don't represent a valid
//         address range.
//
//     NV_ERR_INVALID_DEVICE:
//         The range group is non-migratable and at least one page in the VA
//         range either does not have a preferred location or its preferred
//         location is a fault-capable GPU.
//
//     NV_ERR_OBJECT_NOT_FOUND:
//         rangeGroupId was not created by a previous call to
//         UvmCreateRangeGroup.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmSetRangeGroup(void     *base,
                           NvLength  length,
                           NvU64     rangeGroupId);

//------------------------------------------------------------------------------
// UvmPreventMigrationRangeGroups
//
// Migrates all pages associated with the specified range groups to their
// preferred location and prevents them from being migrated on faults from
// either the CPU or the GPU. Any unpopulated pages are populated at the
// preferred location. If any page does not have a preferred location or if the
// preferred location is a fault-capable GPU, an error is returned. All the
// specified range groups must be valid range groups allocated using
// UvmCreateRangeGroup.
//
// All pages associated with the specified range groups are mapped at the
// preferred location and from all the GPUs present in the accessed-by list of
// those pages, provided establishing a mapping is possible. If any page
// associated with any of the specified range groups has a preferred location
// set to a non-fault-capable GPU, and another non-fault-capable GPU is in the
// accessed-by list of the page but P2P support between both GPUs is not
// enabled, an error is returned.
//
// GPUs are allowed to map any pages belonging to these range groups on faults.
// If establishing such a mapping is not possible, the fault is fatal.
//
// Existing CPU mappings to any pages belonging to these range groups are
// revoked, even if the pages are in system memory and even if the CPU is in
// the accessed-by list of those pages. The CPU is not allowed to map these
// pages on faults even if they are located in system memory and so, CPU faults
// to these pages are always fatal.
//
// Multiple calls to UvmPreventMigrationRangeGroups are not refcounted. i.e.
// calling UvmPreventMigrationRangeGroups on a range group on which
// UvmPreventMigrationRangeGroups has already been called results in a no-op.
//
// Arguments:
//     rangeGroupIds: (INPUT)
//         An array of range group IDs.
//
//     numGroupIds: (INPUT)
//         Number of items in the rangeGroupIds array.
//
// Errors:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_OBJECT_NOT_FOUND:
//         One or more rangeGroupIds was not found.
//
//     NV_ERR_INVALID_ARGUMENT:
//         A NULL pointer was passed in for rangeGroupIds or numGroupIds was
//         zero.
//
//     NV_ERR_INVALID_DEVICE:
//         At least one page in one of the VA ranges associated with these range
//         groups does not have a preferred location or its preferred location
//         is a fault-capable GPU. Or the preferred location has been set to a
//         non-fault-capable GPU, and another non-fault-capable GPU is present
//         in the accessed-by list of a page but P2P support between both GPUs
//         has not been enabled.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmPreventMigrationRangeGroups(const NvU64 *rangeGroupIds,
                                         NvLength     numGroupIds);

//------------------------------------------------------------------------------
// UvmAllowMigrationRangeGroups
//
// Undoes the effect of UvmPreventMigrationRangeGroups. Pages associated with
// these range groups are now allowed to migrate at any time, and CPU or GPU
// faults to these pages are no longer fatal. All the specified range groups
// must be valid range groups allocated using UvmCreateRangeGroup.
//
// Multiple calls to UvmAllowMigrationRangeGroups are not refcounted. i.e.
// calling UvmAllowMigrationRangeGroups on a range group on which
// UvmAllowMigrationRangeGroups has already been called results in a no-op.
//
// Arguments:
//     rangeGroupIds: (INPUT)
//         An array of range group IDs.
//
//     numGroupIds: (INPUT)
//         Number of items in the rangeGroupIds array.
//
// Errors:
//     NV_ERR_OBJECT_NOT_FOUND:
//         One or more rangeGroupIds was not found.
//
//     NV_ERR_INVALID_ARGUMENT:
//         A NULL pointer was passed in for rangeGroupIds or numGroupIds was
//         zero.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmAllowMigrationRangeGroups(const NvU64 *rangeGroupIds,
                                       NvLength     numGroupIds);

//------------------------------------------------------------------------------
// UvmAlloc
//
// Creates a new mapping in the virtual address space of the process, populates
// it at the specified preferred location, maps it on the provided list of
// processors if feasible and associates the range with the given range group.
//
// This API is equivalent to the following code sequence:
//     UvmMemMap(base, length);
//     UvmSetPreferredLocation(base, length, preferredLocationUuid);
//     for (i = 0; i < accessedByCount; i++) {
//         UvmSetAccessedBy(base, length, &accessedByUuids[i]);
//     }
//     UvmSetRangeGroup(base, length, rangeGroupId);
//     UvmMigrate(base, length, preferredLocationUuid, 0);
//
// Please see those APIs for further details on their behavior. If an error is
// encountered during any part of the sequence, the completed portion will be
// undone.
//
// The VA range can be unmapped and freed via a call to UvmFree.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     preferredLocationUuid: (INPUT)
//         UUID of the preferred location for this VA range.
//
//     accessedByUuids: (INPUT)
//         UUIDs of all processors that should have persistent mappings to this
//         VA range.
//
//     accessedByCount: (INPUT)
//         Number of elements in the accessedByUuids array.
//
//     rangeGroupId: (INPUT)
//         ID of the range group to associate this VA range with.
//
// Errors:
//     NV_ERR_UVM_ADDRESS_IN_USE:
//         The requested address range overlaps with an existing allocation.
//
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned or the range was not
//         previously reserved via UvmReserveVa.
//
//     NV_ERR_INVALID_DEVICE:
//         Either preferredLocationUuid or one of the UUIDs in the
//         accessedByUuids array was not registered or the UUID represents a GPU
//         that has no VA space registered for it.
//
//     NV_ERR_OBJECT_NOT_FOUND:
//         rangeGroupId was not found.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmAlloc(void                  *base,
                   NvLength               length,
                   const NvProcessorUuid *preferredLocationUuid,
                   const NvProcessorUuid *accessedByUuids,
                   NvLength               accessedByCount,
                   NvU64                  rangeGroupId);

//------------------------------------------------------------------------------
// UvmFree
//
// Frees a VA range previously allocated via one of the UVM allocator APIs,
// namely either UvmAlloc, UvmMemMap, UvmCreateExternalRange,
// UvmMapDynamicParallelismRegion or UvmAllocSemaphorePool.
//
// For VA ranges allocated via UvmAlloc, UvmMemMap or UvmAllocSemaphorePool, all
// CPU and GPU page table mappings are cleared and all allocated pages are
// freed.
//
// For VA ranges allocated via UvmCreateExternalRange, all GPU page table
// mappings are cleared. No CPU page table mappings for this range are affected,
// and no physical pages for this range are freed.
//
// For VA ranges allocated via UvmMapDynamicParallelismRegion, all GPU page
// table mappings are cleared. No CPU page table mappings for this range are
// affected.
//
// The base address of the VA range to be freed must match the base address used
// when allocating the range. If the VA range came from a region previously
// reserved via UvmReserveVa, then this VA range is put back in the reserved
// state.
//
// Note that the reason this API does not take a length argument is because this
// API is modeled after the C library free() API. Partial frees are not allowed
// and the UVM usermode layer tracks the base and length of each allocated
// range, so having a length argument would be redundant. This also eliminates
// the need for the caller to track the length of each allocation.
//
// Arguments:
//     base: (INPUT)
//         Starting address of the range to be freed. This must be match an
//         address that was obtained via a UVM allocator API.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base does not match an address that was passed into a UVM allocator
//         API.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmFree(void *base);

//------------------------------------------------------------------------------
// UvmCleanUpZombieResources
//
// Clean up resources left by processes that specify
// UVM_INIT_FLAGS_MULTI_PROCESS_SHARING_MODE. Resources not freed before
// termination by such processes are not immediately freed by UVM if another
// processes is using the same UVM file.
//
// Errors:
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmCleanUpZombieResources(void);

//------------------------------------------------------------------------------
// UvmAllocSemaphorePool
//
// Allocates memory from which semaphores can be suballocated and used to order
// work between UVM and CUDA as described in UvmMigrateAsync.
//
// The virtual address range specified by (base, length) must have been
// previously reserved via a call to UvmReserveVa. Both base and length must be
// aligned to the smallest page size supported by the CPU.
//
// The pages are populated in CPU memory and zero initialized. They are mapped
// on the CPU and in all registered GPU VA spaces. They will also be mapped in
// any GPU VA spaces registered after this call. The pages are non-migratable
// and the GPU mappings are persistent, which makes them safe to access from
// non-fault-capable HW engines.
//
// By default, all mappings to this VA range have read, write and atomic access
// and are uncached. This behavior can be overridden for GPUs by explicitly
// specifying the mapping and caching attributes through this API. At most one
// GPU may cache the allocation, in which case no other processor should write
// to it. These GPUs must have been registered via UvmRegisterGpu. These GPUs
// do not need to have a GPU VA space registered at the time of this API call.
// Overriding default mapping and caching attributes for the CPU is disallowed.
// If a new GPU is registered or a currently registered GPU is unregistered via
// UvmUnregisterGpu and then re-registered, default mapping and caching
// attributes will be applied for that GPU.
//
// The VA range must lie within the largest possible virtual address supported
// by all GPUs that currently have a GPU VA space registered for them. Also, if
// a GPU VA space is registered in the future for a GPU which is unable to map
// this allocation, that GPU VA space registration will fail.
//
// The pages in this VA range cannot be associated with range groups, cannot be
// the target for read duplication, cannot have a preferred location set, and
// cannot have any accessed-by processors.
//
// The VA range can be unmapped and freed via a call to UvmFree.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     perGpuAttribs: (INPUT)
//         List of per GPU mapping and caching attributes. GPUs not in the list
//         are mapped with default attributes.
//
//     gpuAttribsCount: (INPUT)
//         Number of entries in the perGpuAttribs array.
//
// Errors:
//     NV_ERR_UVM_ADDRESS_IN_USE:
//         The requested address range overlaps with an existing allocation.
//
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned or the range was not
//         previously reserved via UvmReserveVa.
//
//     NV_ERR_OUT_OF_RANGE:
//         The VA range exceeds the largest virtual address supported by one or
//         more registered GPUs.
//
//     NV_ERR_INVALID_DEVICE:
//         At least one of the UUIDs in the perGpuAttribs list was either not
//         registered or is the UUID of the CPU.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_INVALID_ARGUMENT:
//         perGpuAttribs is NULL but gpuAttribsCount is non-zero or vice-versa,
//         or caching is requested on more than one GPU.
//
//     NV_ERR_NOT_SUPPORTED:
//         The current process is not the one which called UvmInitialize, and
//         UVM_INIT_FLAGS_MULTI_PROCESS_SHARING_MODE was not specified to
//         UvmInitialize.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmAllocSemaphorePool(void                          *base,
                                NvLength                       length,
                                const UvmGpuMappingAttributes *perGpuAttribs,
                                NvLength                       gpuAttribsCount);

//------------------------------------------------------------------------------
// UvmMigrate
//
// Migrates the backing of a given virtual address range to the specified
// destination processor. If any page in the VA range is unpopulated, it is
// populated at the destination processor. The migrated pages in the VA range
// are also mapped on the destination processor.
//
// Both base and length must be aligned to the smallest page size supported by
// the CPU. The VA range must lie within the largest possible virtual address
// supported by the specified processor.
//
// The virtual address range specified by (base, length) must have been
// allocated via a call to either UvmAlloc or UvmMemMap, or be supported
// system-allocated pageable memory.
//
// If the input virtual range corresponds to system-allocated pageable memory,
// and there is at least one GPU in the system that supports transparent access
// to pageable memory, the behavior described in the next paragraphs does not
// take effect. Instead, the driver will first populate any unpopulated pages
// according to the memory policy defined by the calling process and address
// range. Then, pages will be migrated to the requested processor. If the
// destination processor is the CPU, and the memory policy has not defined
// preferred CPU memory nodes or the given preferredCpuMemoryNode is in the
// mask of preferred memory nodes, the driver will try to migrate memory to
// preferredCpuMemoryNode first, and will fallback to the rest of CPU the nodes
// if it doesn't succeed. If pages were already resident on any CPU memory node,
// they will not be migrated.
//
// If the input virtual range corresponds to system-allocated pageable memory,
// and UvmIsPageableMemoryAccessSupported reports that pageable memory access
// is supported, then the driver will populate any unpopulated pages at the
// destination processor and migrate the data from any source location to the
// destination. Pages in the VA range are migrated even if their preferred
// location is set to a processor other than the destination processor.
// If the accessed-by list of any of the pages in the VA range is not empty,
// then mappings to those pages from all the appropriate processors are updated
// to refer to the new location if establishing such a mapping is possible.
// Otherwise, those mappings are cleared.
// Note that in this case, software managed pageable memory does not support
// migration of MAP_SHARED, file-backed, or PROT_NONE mappings.
//
// If any pages in the given VA range are associated with a range group which
// has been made non-migratable via UvmPreventMigrationRangeGroups, then those
// pages are not migrated and the mappings on the destination processor for
// those pages are left unmodified. If the VA range is associated with a
// migratable range group and the destination processor is a non-fault-capable
// GPU, then an error is returned if that GPU is in the accessed-by list of the
// VA range but that GPU is not the preferred location.
//
// If read duplication is enabled on any pages in the VA range, then those pages
// are read duplicated at the destination processor, leaving the source copy, if
// present, intact with only its mapping changed to read-only if it wasn't
// already mapped that way.
//
// Pages in the VA range are migrated even if their preferred location is set to
// a processor other than the destination processor.
//
// If the accessed-by list of any of the pages in the VA range is not empty,
// then mappings to those pages from all the appropriate processors are updated
// to refer to the new location if establishing such a mapping is possible.
// Otherwise, those mappings are cleared.
//
// If fewer than the number of requested pages were migrated,
// NV_WARN_MORE_PROCESSING_REQUIRED is returned. An example scenario where this
// could happen is when UvmPreventMigrationRangeGroups has been called on a
// range group associated with some pages in this range. If fewer than the
// number of requested pages were migrated due to insufficient memory to
// allocate physical pages or page tables, then NV_ERR_NO_MEMORY is returned.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     destinationUuid: (INPUT)
//         UUID of the destination processor to migrate pages to.
//
//     preferredCpuMemoryNode: (INPUT)
//         Preferred CPU NUMA memory node used if the destination processor is
//         the CPU. This argument is ignored if the given virtual address range
//         corresponds to managed memory.
//
// Error codes:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned, or the range does not
//         represent a migratable allocation created via UvmMemMap, or the
//         range is pageable memory and the system does not support accessing
//         pageable memory, or the range does not represent a supported
//         Operating System allocation.
//
//     NV_ERR_OUT_OF_RANGE:
//         The VA range exceeds the largest virtual address supported by the
//         destination processor.
//
//     NV_ERR_INVALID_DEVICE:
//         destinationUuid does not represent a valid processor such as a CPU or
//         a GPU with a GPU VA space registered for it. Or destinationUuid is a
//         non-fault-capable GPU, and that GPU is present in the accessed-by
//         list of the VA range but that GPU is not the preferred location.
//
//     NV_ERR_NO_MEMORY:
//         There was insufficient memory to allocate physical pages or page
//         tables to complete the migration. Or internal memory allocation
//         failed.
//
//     NV_ERR_NOT_SUPPORTED:
//         The UVM file descriptor is associated with another process and the
//         input virtual range corresponds to system-allocated pageable memory
//         that cannot be migrated from this process.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//     NV_WARN_MORE_PROCESSING_REQUIRED:
//         Fewer than the number of requested pages were migrated because some
//         pages were associated with a non-migratable range group.
//
//------------------------------------------------------------------------------
#if UVM_API_REV_IS_AT_MOST(5)
NV_STATUS UvmMigrate(void                  *base,
                     NvLength               length,
                     const NvProcessorUuid *destinationUuid);
#else
NV_STATUS UvmMigrate(void                  *base,
                     NvLength               length,
                     const NvProcessorUuid *destinationUuid,
                     NvU32                  preferredCpuMemoryNode);
#endif

//------------------------------------------------------------------------------
// UvmMigrateAsync
//
// Migrates the backing of a given virtual address range to the specified
// destination processor. The behavior of this API is exactly the same as that
// of UvmMigrate except for the differences outlined below.
//
// When this call returns NV_OK, the migration operation is considered to be
// in-flight and can be synchronized upon by waiting for the specified payload
// to be written at the given semaphore address. The semaphore address must be
// 4-byte aligned and must fall within a VA range allocated using
// UvmAllocSemaphorePool. It is up to the caller to ensure that the payload has
// been written before reusing the address in a subsequent UvmMigrateAsync call.
// Specifying a semaphore address is optional. If the semaphore address is NULL
// the payload must be zero.
//
// The API makes no guarantees about how many pages will be migrated, and there
// is no provision to detect errors that occur during the in-flight operations.
// However, the API does guarantee that the semaphore will eventually be
// released regardless of errors during in-flight operations, as long as the API
// call itself returned NV_OK.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     destinationUuid: (INPUT)
//         UUID of the destination processor to migrate pages to.
//
//     preferredCpuMemoryNode: (INPUT)
//         Preferred CPU NUMA memory node used if the destination processor is
//         the CPU. This argument is ignored if the given virtual address range
//         corresponds to managed memory.
//
//     semaphoreAddress: (INPUT)
//         Base address of the semaphore.
//
//     semaphorePayload: (INPUT)
//         Payload to be written at semaphoreAddress when the operation
//         completes. Must be zero if semaphoreAddress is NULL.
//
// Error codes:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned, or the range does not
//         represent a migratable allocation created via UvmMemMap, or the
//         range is pageable memory and the system does not support accessing
//         pageable memory, or the range does not represent a supported
//         Operating System allocation, or the semaphoreAddress isn't properly
//         aligned, or isn't suballocated from a semaphore pool.
//
//     NV_ERR_OUT_OF_RANGE:
//         The VA range exceeds the largest virtual address supported by the
//         destination processor.
//
//     NV_ERR_INVALID_DEVICE:
//         destinationUuid does not represent a valid processor such as a CPU or
//         a GPU with a GPU VA space registered for it. Or destinationUuid is a
//         non-fault-capable GPU, and that GPU is present in the accessed-by
//         list of the VA range but that GPU is not the preferred location.
//
//     NV_ERR_INVALID_ARGUMENT:
//         semaphoreAddress is NULL and semaphorePayload is not zero.
//
//     NV_ERR_NO_MEMORY:
//         There was insufficient memory to allocate physical pages or page
//         tables to complete the migration. Or internal memory allocation
//         failed.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//     NV_WARN_MORE_PROCESSING_REQUIRED:
//         Fewer than the number of requested pages were migrated because some
//         pages were associated with a non-migratable range group.
//
//------------------------------------------------------------------------------
#if UVM_API_REV_IS_AT_MOST(5)
NV_STATUS UvmMigrateAsync(void                  *base,
                          NvLength               length,
                          const NvProcessorUuid *destinationUuid,
                          void                  *semaphoreAddress,
                          NvU32                  semaphorePayload);
#else
NV_STATUS UvmMigrateAsync(void                  *base,
                          NvLength               length,
                          const NvProcessorUuid *destinationUuid,
                          NvU32                  preferredCpuMemoryNode,
                          void                  *semaphoreAddress,
                          NvU32                  semaphorePayload);
#endif

//------------------------------------------------------------------------------
// UvmMigrateRangeGroup
//
// Migrates the backing of all virtual address ranges associated with the given
// range group to the specified destination processor. The behavior of this API
// is equivalent to calling UvmMigrate on each VA range associated with this
// range group. The value for the preferredCpuMemoryNode is irrelevant in this
// case as it only applies to migrations of pageable address, which cannot be
// used to create range groups.
//
// Any errors encountered during migration are returned immediately. No attempt
// is made to migrate the remaining unmigrated ranges and the ranges that are
// already migrated are not rolled back to their previous location.
//
// The range group id specified must have been allocated via
// UvmCreateRangeGroup.
//
// Arguments:
//     rangeGroupId: (INPUT)
//         Id of the range group whose associated VA ranges have to be migrated.
//
//     destinationUuid: (INPUT)
//         UUID of the destination processor to migrate pages to.
//
// Error codes:
//     NV_ERR_OBJECT_NOT_FOUND:
//         Either UVM_RANGE_GROUP_ID_NONE was specified or the rangeGroupId was
//         not found.
//
//     NV_ERR_INVALID_DEVICE:
//         destinationUuid does not represent a valid processor such as a CPU or
//         a GPU with a GPU VA space registered for it.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_OUT_OF_RANGE:
//         One or more of the VA ranges exceeds the largest virtual address
//         supported by the destination processor.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//     NV_WARN_MORE_PROCESSING_REQUIRED:
//         Fewer than requested pages were migrated because for example, the
//         range group was non-migratable.
//
//------------------------------------------------------------------------------
NV_STATUS UvmMigrateRangeGroup(NvU64                  rangeGroupId,
                               const NvProcessorUuid *destinationUuid);

//------------------------------------------------------------------------------
// UvmPopulatePageable
//
// Forces the population of the given virtual address range. Memory will be
// populated by the system according to the memory policy defined by the calling
// process and address range.
//
// This function only supports pageable memory. None of the pages within the
// virtual address range specified by (base, length) may belong to a virtual
// address range allocated or registered using any of the UVM
// allocation/mapping APIs. Also, all pages must be mapped with at least read
// permissions.
//
// If fewer than the number of requested pages were populated, NV_ERR_NO_MEMORY
// is returned.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned, the range does not
//         represent a supported Operating System allocation, or the range
//         contains pages not mapped with at least read permissions.
//
//     NV_ERR_NO_MEMORY:
//         Fewer than the number of requested pages were populated, likely
//         because the system ran out of memory.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmPopulatePageable(void     *base,
                              NvLength  length);

//------------------------------------------------------------------------------
// UvmMemMap
//
// Creates a new mapping in the virtual address space of the process that is
// valid for access from any fault-capable CPU or GPU.
//
// The virtual address range specified by (base, length) must have been
// previously reserved via a call to UvmReserveVa. Both base and length must be
// aligned to the smallest page size supported by the CPU. Note that using a
// larger alignment for base and length, such as the largest GPU page size, may
// result in higher performance.
//
// The pages in the VA range are zero initialized. They are typically populated
// on demand, for example, through CPU or GPU faults.
//
// The VA range can be unmapped and freed via a call to UvmFree.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
// Errors:
//     NV_ERR_UVM_ADDRESS_IN_USE:
//         The requested address range overlaps with an existing allocation.
//
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned or the range was not
//         previously reserved via UvmReserveVa.
//
//     NV_ERR_NOT_SUPPORTED:
//         The current process is not the one which called UvmInitialize, and
//         UVM_INIT_FLAGS_MULTI_PROCESS_SHARING_MODE was not specified to
//         UvmInitialize.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmMemMap(void     *base,
                    NvLength  length);

//------------------------------------------------------------------------------
// UvmCreateExternalRange
//
// Create a VA range within the process's address space reserved for external
// allocations. The VA range is not mapped to any physical allocation at the
// time of creation. Once an external VA range has been created using this API,
// the user is free to map any number of physical allocations within the VA
// range (see UvmMapExternalAllocation and UvmMapExternalSparse for more
// details).
//
// The virtual address range, itself, does not impose any restrictions on the
// alignment of the physical allocations mapped within it. However, both base
// and length must be aligned to 4K.
//
// The VA range must not overlap with an existing VA range, irrespective of
// whether the existing range corresponds to a UVM allocation or an external
// allocation.
//
// It is allowed (but not required) for the VA range to come from a region
// previously reserved via UvmReserveVa.
//
// Any mappings created within this VA range are considered non-migratable.
// Consequently, pages cannot be associated with range groups, cannot be
// the target for read duplication, cannot have a preferred location set,
// cannot have any accessed-by processors, and any GPU faults within this range
// are fatal.
//
// Mappings within this range neither create nor modify any CPU mappings, even
// if the mappings came from a region previously reserved via UvmReserveVa.
// This implies that CPU accesses to any mappings within this range will cause
// a fatal fault if it's not mapped.
//
// The VA range is not reclaimed until UvmFree is called on it even if it is
// fully unmapped from all GPUs either explicitly via UvmUnmapExternal or
// implicitly via APIs such as UvmUnregisterGpu, UvmUnregisterGpuVaSpace,
// UvmDisablePeerAccess, etc.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base is NULL or length is zero or at least one of base and length is
//         not aligned to 4K.
//
//     NV_ERR_UVM_ADDRESS_IN_USE:
//         The requested address range overlaps with an existing allocation.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//------------------------------------------------------------------------------
NV_STATUS UvmCreateExternalRange(void     *base,
                                 NvLength  length);

//------------------------------------------------------------------------------
// UvmMapExternalAllocation
//
// Maps an allocation that was allocated outside of UVM on the specified list of
// GPUs. The external allocation can be unmapped from a specific GPU using
// UvmUnmapExternal or from all GPUs using UvmFree.
//
// The virtual address range specified by (base, length) must fall within a VA
// range previously created with UvmCreateExternalRange. A GPU VA space must
// have been registered for each GPU in the list. The (base, length) range must
// lie within the largest possible virtual address supported by the specified
// GPUs.
//
// The page size used for the mapping is the largest supported page size less
// than or equal to the alignments of base, length, offset, and the allocation
// page size.
//
// If the range specified by (base, length) falls within any existing mappings,
// the behavior is the same as if UvmUnmapExternal with the range specified by
// (base, length) had been called first, provided that base and length are
// aligned to the page size used for the existing one.
//
// If the allocation resides in GPU memory, that GPU must have been registered
// via UvmRegisterGpu. If the allocation resides in GPU memory and a mapping is
// requested for a different GPU, then P2P support should have been enabled via
// UvmEnablePeerAccess between the two GPUs if connected by PCIe.
//
// The allocation can be mapped with different access permissions and
// cacheability settings on different GPUs. The settings to use for each GPU are
// specified in the perGpuAttribs array. It is also legal to map the allocation
// multiple times on the same GPU with different access permissions and
// cacheability settings as long as all of the mappings are fully contained
// within the VA range. Calling this API with the same GPU appearing multiple
// times in the list is equivalent to calling the API multiple times on the same
// GPU.
//
// Access permissions control which of 3 types of accesses (reads, writes and
// atomics) are allowed for this VA range. Any GPU accesses of a disallowed kind
// result in a fatal fault. If UvmGpuMappingTypeDefault is specified, the UVM
// driver chooses the appropriate access permissions. On non-fault-capable GPUs,
// specifying either UvmGpuMappingTypeReadOnly or UvmGpuMappingTypeReadWrite is
// disallowed.
//
// Caching can be forced on or off, or can be left to the UVM driver to manage
// by specifying UvmGpuCachingTypeDefault. Specifying UvmGpuCachingTypeDefault
// will result in a cached mapping only if the allocation is physically located
// in that GPU's memory. Note that caching here only refers to GPU L2 caching
// and not GPU L1 caching as the latter is controlled via instruction opcode
// modifiers and not through page table attributes.
//
// Format and element bits can be forced, or can be left to the UVM driver to
// manage by specifying UvmGpuFormatTypeDefault and
// UvmGpuFormatElementBitsDefault respectively. UvmGpuFormatTypeDefault and
// UvmGpuFormatElementBitsDefault are mutually inclusive, meaning that if one
// of them is specified then the other one must be specified too.
//
// Compression type of the specified virtual address range can be specified with
// UvmGpuCompressionType mapping attribute.
//
// The UVM driver retains a reference on the external allocation as long as at
// least one GPU has any portion of that allocation mapped.
//
// The pages in this mapping are not zero initialized or modified in any way.
//
// Note that calling UvmUnregisterGpuVaSpace will also unmap all mappings
// created via this API on the GPU that the GPU VA space is associated with.
// Also, if a mapping has to be created on a GPU for a physical allocation that
// resides on a PCIe peer GPU, then peer-to-peer support must have been enabled
// between those two GPUs via UvmEnablePeerAccess. Disabling peer-to-peer
// support via UvmDisablePeerAccess will tear down all peer mappings between the
// two GPUs.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     offset: (INPUT)
//         Offset, in bytes, in the physical allocation at which the VA range
//         must be mapped.
//
//     perGpuAttribs: (INPUT)
//         List of per GPU mapping and caching attributes. GPUs not in the list
//         are not affected.
//
//     gpuAttribsCount: (INPUT)
//         Number of entries in the perGpuAttribs array.
//
//     platformParams: (INPUT)
//         Platform specific parameters that identify the allocation.
//         On Linux: RM ctrl fd, hClient and hMemory.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         One of the following occurred:
//         - base is NULL.
//         - length is zero.
//         - The requested address range does not fall entirely within an
//           existing external VA range created with a single call to
//           UvmCreateExternalRange.
//         - The mapping page size allowed by the alignments of base, length,
//           and offset is smaller than the minimum supported page size on the
//           GPU.
//         - base or base + length fall within an existing mapping but are not
//           aligned to that mapping's page size.
//
//     NV_ERR_OUT_OF_RANGE:
//         The range specified by (base, length) exceeds the largest virtual
//         address supported by one or more of the specified GPUs.
//
//     NV_ERR_INVALID_OFFSET:
//         - offset+length exceeds the allocation size.
//
//     NV_ERR_INVALID_DEVICE:
//         One of the following occurred:
//         - The allocation resides in GPU memory whose UUID was not registered.
//         - One or more of the UUIDs in the perGpuAttribs list was either not
//           registered or has no GPU VA space registered for it.
//         - The allocation resides in GPU memory and a mapping was requested
//           for a different GPU and P2P support was not enabled between them.
//         - The UUID of the CPU was specified in the perGpuAttribs list.
//         - UvmGpuCompressionTypeEnabledNoPlc compression type was used on one
//           or more GPUs that don't support PLC.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the following occurred:
//         - perGpuAttribs is NULL.
//         - gpuAttribsCount is zero.
//         - an invalid mapping type was specified.
//         - an invalid caching type was specified.
//         - an invalid format/element bits combination was specified.
//         - an invalid compression type was specified.
//         - UvmGpuCompressionTypeEnabledNoPlc compression type was used with a
//           non-compressible physical allocation.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmMapExternalAllocation(void                              *base,
                                   NvLength                           length,
                                   NvLength                           offset,
                                   const UvmGpuMappingAttributes     *perGpuAttribs,
                                   NvLength                           gpuAttribsCount,
                                   const UvmAllocationPlatformParams *platformParams);

//------------------------------------------------------------------------------
// UvmMapExternalSparse
//
// Create a Sparse mapping for the virtual address range specified by (base,
// length). The mapping does not have any physical backing, rather the PTEs use
// a special pattern. The virtual address range specified by (base, length) must
// be fully contained within a virtual address range previously created with
// UvmCreateExternalRange.
//
// Virtual address ranges with Sparse mappings will not generate any faults when
// accessed. Instead, writes will be discarded and reads will return 0.
//
// Sparse mappings are supported only on fault-capable GPUs and only for 64K
// pages, so the virtual address range specified by (base, length) must be
// aligned to 64K.
//
// If the range specified by (base, length) falls within any existing mappings,
// the behavior is the same as if UvmUnmapExternal with the range specified by
// (base, length) had been called first.
//
// Note that calling UvmUnregisterGpuVaSpace will also unmap all mappings
// created via this API on the GPU that the GPU VA space is associated with.
// Notably the mappings won't be recreated when the GPU VA space is
// re-registered.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range. The address must be
//         aligned on a 64K boundary.
//
//     length: (INPUT)
//         Length, in bytes, of the range. The length must be 64K aligned.
//
//
//     gpuUuid: (INPUT)
//         UUID of the GPU to map the sparse region on.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         One of the following occurred:
//         - base is NULL.
//         - length is zero.
//         - The requested address range does not fall entirely within an
//           existing external VA range created with a single call to
//           UvmCreateExternalRange.
//         - At least one of base and length is not aligned to a 64K
//           boundary.
//
//     NV_ERR_OUT_OF_RANGE:
//         The range specified by (base, length) exceeds the largest virtual
//         address supported by the specified GPU.
//
//     NV_ERR_INVALID_DEVICE:
//         One of the following occurred:
//         - The specified GPU was not registered.
//         - The GPU specified has no VA space registered for it.
//         - The UUID of the CPU was specified.
//         - Sparse mappings are not supported on the specified GPU.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//------------------------------------------------------------------------------
NV_STATUS UvmMapExternalSparse(void                  *base,
                               NvLength               length,
                               const NvProcessorUuid *gpuUuid);

//------------------------------------------------------------------------------
// UvmUnmapExternal
//
// Unmaps a virtual address range that was mapped using UvmMapExternalAllocation
// or UvmMapExternalSparse from the specified GPU. The range specified by (base,
// length) must be fully contained within a single External VA range created
// with UvmCreateExternalRange.
//
// If the range specified by (base, length) range partially overlaps existing
// mappings, the overlapping portion of the existing mappings will be unmapped
// provided that the split points are aligned to the mappings' respective page
// sizes. Otherwise, the overlapping portions of the existing mappings will be
// left in an undefined state.
//
// Note that the VA range is not reclaimed until UvmFree is called on it even if
// all mappings in the created range have been unmapped from all GPUs via this
// API.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         The length of the virtual address range.
//
//     gpuUuid: (INPUT)
//         UUID of the GPU to unmap the VA range from.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         One of the following has occurred:
//         - base is NULL.
//         - The requested address range does not fall entirely within an
//           existing external VA range created with a single call to
//           UvmCreateExternalRange.
//         - base or base + length fall within an existing mapping but are not
//           aligned to that mapping's page size.
//
//     NV_ERR_INVALID_DEVICE:
//         Either gpuUuid does not represent a valid registered GPU or the VA
//         range corresponding to the given base address is not mapped on the
//         specified GPU.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmUnmapExternal(void                  *base,
                           NvLength               length,
                           const NvProcessorUuid *gpuUuid);

// TODO: Bug 2732305: Remove this declaration when the new external APIs have
//       been implemented.
NV_STATUS UvmUnmapExternalAllocation(void                  *base,
                                     const NvProcessorUuid *gpuUuid);

//------------------------------------------------------------------------------
// UvmMapDynamicParallelismRegion
//
// Creates a special mapping required for dynamic parallelism. The mapping
// doesn't have any physical backing, it's just a PTE with a special kind.
//
// The virtual address range specified by (base, length) must cover exactly one
// GPU page, so length must be a page size supported by the GPU and base must be
// aligned to that page size. The VA range must not overlap with an existing
// mapping for the GPU. A GPU VA space must have been registered for the GPU and
// the GPU must support dynamic parallelism.
//
// The mapping is created immediately and not modified until a call to UvmFree
// Calling UvmFree frees the GPU page table mapping. The range cannot be
// associated with range groups and any GPU faults within this range are fatal.
// Also, the pages cannot be the target for read duplication, cannot have a
// preferred location set, and cannot have any accessed-by processors.
//
// Note that calling UvmUnregisterGpuVaSpace will also unmap all mappings
// created via this API on the GPU that the GPU VA space is associated with.
// Notably the mappings won't be recreated when the GPU VA space is
// re-registered, but the range should still be destroyed with UvmFree.
//
// This call neither creates nor modifies any CPU mappings, even if the VA range
// came from a region previously reserved via UvmReserveVa. This implies that
// CPU accesses to this range will cause a fatal fault if it's not mapped.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range. Must be equal to a page size
//         supported by the GPU.
//
//     gpuUuid: (INPUT)
//         UUID of the GPU to map the dynamic parallelism region on.
//
// Errors:
//     NV_ERR_UVM_ADDRESS_IN_USE:
//         The requested address range overlaps with an existing allocation.
//
//     NV_ERR_INVALID_ADDRESS:
//         base is NULL or not aligned to length or length is not a page size
//         supported by the GPU.
//
//     NV_ERR_OUT_OF_RANGE:
//         The VA range exceeds the largest virtual address supported by one or
//         more of the specified GPUs.
//
//     NV_ERR_INVALID_DEVICE:
//         The gpuUuid was either not registered, has no GPU VA space
//         registered for it, or the GPU doesn't support dynamic parallelism.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmMapDynamicParallelismRegion(void                  *base,
                                         NvLength               length,
                                         const NvProcessorUuid *gpuUuid);

//------------------------------------------------------------------------------
// UvmEnableReadDuplication
//
// Enables read duplication on the specified virtual address range, overriding
// the UVM driver's default migration and mapping policy on read faults.
//
// The virtual address range specified by (base, length) must have been
// allocated via a call to either UvmAlloc or UvmMemMap, or be supported
// system-allocated pageable memory. If the input virtual range corresponds to
// system-allocated pageable memory and UvmIsPageableMemoryAccessSupported
// reports that pageable memory access is supported, the behavior described
// below does not take effect, and read duplication will not be enabled for
// the input range.
//
// Both base and length must be aligned to the smallest page size supported by
// the CPU.
//
// On a read fault from a processor on a page in this range, any existing
// mapping to that page from all other processors will be made read-only. If the
// page does not reside in the faulting processor's memory, a duplicate copy of
// the page will be created there. The copy of the page in the faulting
// processor's memory will then be mapped as read-only on that processor. Note
// that a write to this page from any processor will collapse the duplicated
// copies.
//
// If UvmMigrate, UvmMigrateAsync or UvmMigrateRangeGroup is called on any pages
// in this VA range, then those pages will also be read duplicated on the
// destination processor for the migration.
//
// Enabling read duplication on a VA range requires the CPU and all GPUs with
// registered VA spaces to be fault-capable. Otherwise, the migration and
// mapping policies outlined above are not applied until all the
// non-fault-capable GPUs are unregistered via UvmUnregisterGpu. If a
// non-fault-capable GPU is registered after a page has already been
// read-duplicated, then the copies of that page will be collapsed into a single
// page.
//
// If UvmPreventMigrationRangeGroups has been called on the range group that
// this VA range is associated with, then the migration and mapping policies
// outlined above don't take effect until UvmAllowMigrationRangeGroups is called
// for that range group.
//
// If any page in the VA range has a preferred location, then the migration and
// mapping policies associated with this API take precedence over those related
// to the preferred location.
//
// If any pages in this VA range have any processors present in their
// accessed-by list, the migration and mapping policies associated with this
// API override those associated with the accessed-by list.
//
// Multiple calls to this API for the same VA range and the same processor are
// not refcounted, i.e. calling this API on a VA range after it has already been
// called for that same VA range results in a no-op.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned, or the range does not
//         represent a valid UVM allocation, or the range is pageable memory and
//         the system does not support accessing pageable memory, or the range
//         does not represent a supported Operating System allocation.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEnableReadDuplication(void     *base,
                                   NvLength  length);

//------------------------------------------------------------------------------
// UvmDisableReadDuplication
//
// Disables read duplication on the specified virtual address range, and reverts
// the associated policies. This also disables any default read duplication
// heuristics employed by the kernel driver.
//
// The virtual address range specified by (base, length) must have been
// allocated via a call to either UvmAlloc or UvmMemMap, or be supported
// system-allocated pageable memory. If the input virtual range corresponds to
// system-allocated pageable memory and UvmIsPageableMemoryAccessSupported
// reports that pageable memory access is supported, the behavior described
// below does not take effect, and read duplication will not be enabled for
// the input range.
//
// Both base and length must be aligned to the smallest page size supported by
// the CPU.
//
// Any pages in the VA range that are currently read duplicated will be
// collapsed into a single copy. The location for the collapsed copy will be the
// preferred location if the page has a preferred location and was resident at
// that location when this API was called. Otherwise, the location will be
// chosen arbitrarily.
//
// It is ok to call this API only on a subset of the VA range on which
// UvmEnableReadDuplication was called or for a VA range on which
// UvmEnableReadDuplication was never called.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned, or the range does not
//         represent a valid UVM allocation, or the range is pageable memory and
//         the system does not support accessing pageable memory, or the range
//         does not represent a supported Operating System allocation.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//-----------------------------------------------------------------------------
NV_STATUS UvmDisableReadDuplication(void     *base,
                                    NvLength  length);

//------------------------------------------------------------------------------
// UvmSetPreferredLocation
//
// Sets the preferred location for the given virtual address range to be the
// specified processor's memory.
//
// Both base and length must be aligned to the smallest page size supported by
// the CPU. The VA range must lie within the largest possible virtual address
// supported by the specified processor.
//
// The virtual address range specified by (base, length) must have been
// allocated via a call to either UvmAlloc or UvmMemMap, or be supported
// system-allocated pageable memory. If the input range is pageable memory and
// at least one GPU in the system supports transparent access to pageable
// memory, the behavior described below does not take effect and the preferred
// location of the pages in the given range does not change.
//
// If any pages in the VA range are associated with a range group that was made
// non-migratable via UvmPreventMigrationRangeGroups, then those pages are
// migrated immediately to the specified preferred location and mapped according
// to policies specified in UvmPreventMigrationRangeGroups. Otherwise, this API
// neither migrates pages nor does it populate unpopulated pages. Note that if
// the specified preferred location is a fault-capable GPU and at least one page
// in the VA range is associated with a non-migratable range group, then an
// error is returned. Additionally, if the specified preferred location is a
// non-fault capable GPU and at least one page in the VA range is associated
// with a non-migratable range group, an error is returned if another
// non-fault-capable GPU is present in the accessed-by list of that page but P2P
// support has not been enabled between both GPUs.
//
// When a page is in its preferred location, a fault from another processor will
// not cause a migration if a mapping for that page from that processor can be
// established without migrating the page.
//
// When a page migrates away from its preferred location, the mapping on the
// preferred location's processor is cleared so that the next access from that
// processor will cause a fault and migrate the page back to its preferred
// location. In other words, a page is mapped on the preferred location's
// processor only if the page is in its preferred location. Thus, when the
// preferred location changes, mappings to pages in the given range are removed
// from the new preferred location if the pages are resident in a different
// processor. Note that if the preferred location's processor is a GPU, then a
// mapping from that GPU to a page in the VA range is only created if a GPU VA
// space has been registered for that GPU and the page is in its preferred
// location.
//
// If read duplication has been enabled for any pages in this VA range and
// UvmPreventMigrationRangeGroups has not been called on the range group that
// those pages are associated with, then the migration and mapping policies
// associated with UvmEnableReadDuplication override the policies outlined
// above. Note that enabling read duplication on on any pages in this VA range
// does not clear the state set by this API for those pages. It merely overrides
// the policies associated with this state until read duplication is disabled
// for those pages.
//
// If the preferred location processor is present in the accessed-by list of any
// of the pages in this VA range, then the migration and mapping policies
// associated with associated with the accessed-by list.
//
// The state set by this API can be cleared either by calling
// UvmUnsetPreferredLocation for the same VA range or by calling
// UvmUnregisterGpu on this processor if the processor is a GPU. Note that
// calling UvmUnregisterGpuVaSpace will not clear the state set by this API.
// Multiple calls to this API for the same VA range and the same processor are
// not refcounted, i.e. calling this API on a VA range and processor after it
// has already been called for that same VA range and processor results in a
// no-op.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     preferredLocationUuid: (INPUT)
//         UUID of the preferred location.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned, or the range does not
//         represent a valid UVM allocation, or the range is pageable memory and
//         the system does not support accessing pageable memory, or the range
//         does not represent a supported Operating System allocation.
//
//     NV_ERR_OUT_OF_RANGE:
//         The VA range exceeds the largest virtual address supported by the
//         specified processor.
//
//     NV_ERR_INVALID_DEVICE:
//         preferredLocationUuid is neither the UUID of the CPU nor the UUID of
//         a GPU that was registered by this process. Or at least one page in
//         VA range belongs to a non-migratable range group and the specified
//         UUID represents a fault-capable GPU. Or preferredLocationUuid is the
//         UUID of a non-fault-capable GPU and at least one page in the VA range
//         belongs to a non-migratable range group and another non-fault-capable
//         GPU is in the accessed-by list of the same page but P2P support
//         between both GPUs has not been enabled.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmSetPreferredLocation(void                  *base,
                                  NvLength               length,
                                  const NvProcessorUuid *preferredLocationUuid);

//------------------------------------------------------------------------------
// UvmUnsetPreferredLocation
//
// Unsets the preferred location associated with all pages in the specified
// virtual address range, reverting the migration and mapping policies outlined
// in UvmSetPreferredLocation.
//
// Both base and length must be aligned to the smallest page size supported by
// the CPU.
//
// The virtual address range specified by (base, length) must have been
// allocated via a call to either UvmAlloc or UvmMemMap, or be supported
// system-allocated pageable memory. If the input range is pageable memory and
// at least one GPU in the system supports transparent access to pageable
// memory, the behavior described below does not take effect and the preferred
// location of the pages in the given range does not change.
//
// If the VA range is associated with a non-migratable range group, then that
// association is cleared. i.e. the pages in this VA range have their range
// group association changed to UVM_RANGE_GROUP_ID_NONE.
//
// It is ok to call this API only on a subset of the VA range on which
// UvmSetPreferredLocation was called or for a VA range on which
// UvmSetPreferredLocation was never called.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned or the range does not
//         represent a valid UVM allocation, or the range is pageable memory and
//         the system does not support accessing pageable memory, or the range
//         does not represent a supported Operating System allocation.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmUnsetPreferredLocation(void     *base,
                                    NvLength  length);

//------------------------------------------------------------------------------
// UvmSetAccessedBy
//
// Indicates to the UVM driver that the pages in the given virtual address range
// should be mapped on the specified processor whenever establishing such a
// mapping is possible. The purpose of this API is to prevent faults from the
// specified processor to the given VA range as much as possible.
//
// Both base and length must be aligned to the smallest page size supported by
// the CPU. The VA range must lie within the largest possible virtual address
// supported by the specified processor.
//
// The virtual address range specified by (base, length) must have been
// allocated via a call to either UvmAlloc or UvmMemMap, or be supported
// system-allocated pageable memory. If the input range is pageable memory and
// at least one GPU in the system supports transparent access to pageable
// memory, the behavior described below does not take effect and the accessed-by
// processor list of the VA range does not change.
//
// If a page in the VA range is not populated or its current location doesn't
// permit a mapping to be established, then no mapping is created for that page.
// If a page in the VA range migrates to a new location, then the mapping is
// updated to point to the new location if establishing such a mapping is
// possible. If a page in the VA range is associated with a non-migratable range
// group and the specified processor is a non-fault-capable GPU, then an error
// is returned if the mapping cannot be established.
//
// If the specified processor is a GPU and no GPU VA space has been registered
// for it or if the registered GPU VA space gets unregistered, then the policies
// outlined above will take effect the next time a GPU VA space gets registered
// for this GPU.
//
// If read duplication is enabled in any pages in this VA range, then the page
// mapping policy associated with read duplication overrides the mapping policy
// associated with this API.
//
// Similarly, if any page in this VA range has a preferred location, and the
// UUID of the preferred location is the same as the UUID passed in to this API,
// then the mapping policy associated with having a preferred location overrides
// the mapping policy associated with this API.
//
// Note that enabling read duplication or setting a preferred location on any
// pages in this VA range does not clear the state set by this API for those
// pages. It merely overrides the policies associated with this state until read
// duplication is disabled on those pages or their preferred location is
// cleared.
//
// The state set by this API can be cleared either by calling UvmUnsetAccessedBy
// for the same VA range and processor or by calling UvmUnregisterGpu on this
// processor if the processor is a GPU. It is also cleared if the processor is a
// non-fault-capable GPU and the VA range has a preferred location set to a peer
// GPU and peer access is disabled via UvmDisablePeerAccess. Note however that
// calling UvmUnregisterGpuVaSpace will not clear the state set by this API.
//
// Multiple calls to this API for the same VA range and the same processor are
// not refcounted. i.e. calling this API on a VA range and processor after it
// has already been called for that same VA range and processor results in a
// no-op.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     accessedByUuid: (INPUT)
//         UUID of the processor that should have pages in the the VA range
//         mapped when possible.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned or the range does not
//         represent a valid UVM allocation, or the range is pageable memory and
//         the system does not support accessing pageable memory, or the range
//         does not represent a supported Operating System allocation.
//
//     NV_ERR_OUT_OF_RANGE:
//         The VA range exceeds the largest virtual address supported by the
//         specified processor.
//
//     NV_ERR_INVALID_DEVICE:
//         accessedByUuid is neither the UUID of the CPU nor the UUID of a GPU
//         that was registered by this process. Or accessedByUuid is the UUID of
//         a non-fault-capable GPU and the VA range is associated with a
//         non-migratable range group with a preferred location set to another
//         non-fault-capable GPU that doesn't have P2P support enabled with this
//         GPU.
//
//     NV_ERR_NO_MEMORY:
//         accessedByUuid is a non-fault-capable GPU and there was insufficient
//         memory to create the mapping.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmSetAccessedBy(void                  *base,
                           NvLength               length,
                           const NvProcessorUuid *accessedByUuid);

//------------------------------------------------------------------------------
// UvmUnsetAccessedBy
//
// Undoes the effect of UvmSetAccessedBy for the given virtual address range on
// the specified processor, thereby reverting the mapping policies imposed by
// UvmSetAccessedBy.
//
// Both base and length must be aligned to the smallest page size supported by
// the CPU
//
// The virtual address range specified by (base, length) must have been
// allocated via a call to either UvmAlloc or UvmMemMap, or be supported
// system-allocated pageable memory. If the input range is pageable memory and
// at least one GPU in the system supports transparent access to pageable
// memory, the behavior described below does not take effect and the accessed-by
// processor list of the VA range does not change.

//
// Existing mappings to this VA range from the given processor are not affected.
// If any page in the VA range migrates to a different location however, the
// mapping may be cleared or updated based on other mapping policies that are in
// effect.
//
// It is ok to call this API for a subset of a VA range with a accessed-by list
// containing this processor, or for a VA range with an empty accessed-by list.
//
// Arguments:
//     base: (INPUT)
//         Base address of the virtual address range.
//
//     length: (INPUT)
//         Length, in bytes, of the range.
//
//     accessedByUuid: (INPUT)
//         UUID of the processor from which any policies set by
//         UvmSetAccessedBy should be revoked for the given VA range.
//
// Errors:
//     NV_ERR_INVALID_ADDRESS:
//         base and length are not properly aligned or the range does not
//         represent a valid UVM allocation, or the range is pageable memory and
//         the system does not support accessing pageable memory, or the range
//         does not represent a supported Operating System allocation.
//
//     NV_ERR_INVALID_DEVICE:
//         accessedByUuid is neither the UUID of the CPU nor the UUID of a GPU
//         that was registered by this process.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmUnsetAccessedBy(void                  *base,
                             NvLength               length,
                             const NvProcessorUuid *accessedByUuid);

//------------------------------------------------------------------------------
// UvmEnableSystemWideAtomics
//
// Enables software-assisted system-wide atomics support on the specified GPU.
// Any system-wide atomic operation issued from this GPU is now guaranteed to be
// atomic with respect to all accesses from other processors that also support
// system-wide atomics regardless of whether that support is enabled on those
// other processors or not.
//
// The class of atomic operations from the GPU that are considered system-wide
// is GPU architecture dependent. All atomic operations from the CPU are always
// considered to be system-wide and support for system-wide atomics on the CPU
// is always considered to be enabled.
//
// System-wide atomics which cannot be natively supported in hardware are
// emulated using virtual mappings and page faults. For example, assume a
// virtual address which is resident in CPU memory and has CPU memory as its
// preferred location. A GPU with system-wide atomics enabled but without native
// atomics support to CPU memory will not have atomics enabled in its virtual
// mapping of the page that contains that address. If that GPU performs an
// atomic operation, the access will fault, all other processors' mappings to
// that page will have their write permissions revoked, the faulting GPU will be
// granted atomic permissions in its virtual mapping, and the faulting GPU will
// retry its access. Further atomic accesses from that GPU will not cause page
// faults until another processor attempts a write access to the same page.
//
// Multiple calls to this API for the same GPU are not refcounted, i.e. calling
// this API for a GPU for which software-assisted system-wide atomics support
// has already been enabled results in a no-op.
//
// The GPU must have been registered using UvmRegisterGpu prior to making this
// call. By default, software-assisted system-wide atomics support is enabled
// when a GPU is registered.
//
// Arguments:
//     gpuUuid: (INPUT)
//         UUID of the GPU to enable software-assisted system-wide atomics on.
//
// Error codes:
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//     NV_ERR_INVALID_DEVICE:
//         The GPU referred to by gpuUuid was not registered.
//
//     NV_ERR_NOT_SUPPORTED:
//         The GPU does not support system-wide atomic operations, or the GPU
//         has hardware support for scoped atomic operations.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEnableSystemWideAtomics(const NvProcessorUuid *gpuUuid);

//------------------------------------------------------------------------------
// UvmDisableSystemWideAtomics
//
// Disables software-assisted system-wide atomics support on the specified GPU.
// Any atomic operation from this GPU is no longer guaranteed to be atomic with
// respect to accesses from other processors in the system, even if the
// operation has system-wide scope at the instruction level.
//
// The GPU must have been registered using UvmRegisterGpu prior to making this
// call. It is however ok to call this API for GPUs that do not have support for
// system-wide atomic operations enabled. If the GPU is unregistered via
// UvmUnregisterGpu and then registered again via UvmRegisterGpu, support for
// software-assisted system-wide atomics will be enabled.
//
// Arguments:
//     gpuUuid: (INPUT)
//         UUID of the GPU to disable software-assisted system-wide atomics on.
//
// Error codes:
//     NV_ERR_INVALID_DEVICE:
//         The GPU referred to by gpuUuid was not registered.
//
//     NV_ERR_NOT_SUPPORTED:
//         The GPU does not support system-wide atomic operations, or the GPU
//         has hardware support for scoped atomic operations.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDisableSystemWideAtomics(const NvProcessorUuid *gpuUuid);

//------------------------------------------------------------------------------
// UvmGetFileDescriptor
//
// Returns the UVM file descriptor currently being used to call into the UVM
// kernel mode driver. The data type of the returned file descriptor is platform
// specific.
//
// If UvmInitialize has not yet been called, an error is returned. If
// UvmInitialize was called with UVM_AUTO_FD, then the file created during
// UvmInitialize is returned. If UvmInitialize was called with an existing UVM
// file descriptor, then that file descriptor is returned.
//
// Arguments:
//     returnedFd: (OUTPUT)
//         A platform specific file descriptor.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         returnedFd is NULL.
//
//     NV_ERR_INVALID_STATE:
//         UVM was not initialized before calling this function.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmGetFileDescriptor(UvmFileDescriptor *returnedFd);

//------------------------------------------------------------------------------
// UvmIs8Supported
//
// Returns whether the kernel driver has been loaded in UVM 8 mode or not.
//
// Argument:
//     is8Supported: (OUTPUT)
//         Will be set to true (nonzero) if the driver was loaded as UVM 8, or
//         false (zero) if it was loaded as UVM Lite.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         is8Supported is NULL.
//
//     NV_ERR_GENERIC:
//         Unexpected error. We try hard to avoid returning this error code,
//         because it is not very informative.
//
//------------------------------------------------------------------------------
NV_STATUS UvmIs8Supported(NvU32 *is8Supported);

//------------------------------------------------------------------------------
//    Tools API
//------------------------------------------------------------------------------

//------------------------------------------------------------------------------
// UvmDebugGetVersion
//
// Returns the version number of the UVM debug library
// See uvm_types.h for valid verion numbers, e.g. UVM_DEBUG_V1
//
//------------------------------------------------------------------------------
unsigned UvmDebugVersion(void);

//------------------------------------------------------------------------------
// UvmDebugCreateSession
//
// Creates a handle for a debugging session.
//
// When the client initializes, it will pass in a process handle and get a
// session ID for itself. Subsequent calls to the UVM API will take in that
// session ID.
//
// There are security requirements to this call.
// One of the following must be true:
// 1.  The session owner must be running as an elevated user
// 2.  The session owner and target must belong to the same user and the
//     session owner is at least as privileged as the target.
//
// For CUDA 6.0 we can create at most 64 sessions per debugger process.
//
// Arguments:
//     pid: (INPUT)
//         Process id for which the debugging session will be created
//
//     session: (OUTPUT)
//         Handle to the debugging session associated to that pid.
//
// Error codes:
//     NV_ERR_PID_NOT_FOUND:
//         pid is invalid/ not associated with UVM.
//
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Function fails the security check.
//
//     NV_ERR_INSUFFICIENT_RESOURCES:
//         Attempt is made to allocate more than 64 sessions per process.
//
//     NV_ERR_BUSY_RETRY:
//         internal resources are blocked by other threads.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDebugCreateSession(unsigned         pid,
                                UvmDebugSession *session);

//------------------------------------------------------------------------------
// UvmDebugDestroySession
//
// Destroys a debugging session.
//
// Arguments:
//     session: (INPUT)
//         Handle to the debugging session associated to that pid.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         session is invalid.
//
//     NV_ERR_BUSY_RETRY:
//         ebug session is in use by some other thread.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDebugDestroySession(UvmDebugSession session);

//------------------------------------------------------------------------------
// UvmDebugCountersEnable
//
// Enables the counters following the user specified configuration.
//
// The user must fill a list with the configuration of the counters it needs to
// either enable or disable. It can only enable one counter per line.
//
// The structure (UvmCounterConfig) has several fields:
//  - scope: Please see the UvmCounterScope  enum (above), for details.
//  - name: Name of the counter. Please check UvmCounterName for list.
//  - gpuid: Identifies the GPU for which the counter will be enabled/disabled
//           This parameter is ignored in AllGpu scopes.
//  - state: A value of 0 will disable the counter, a value of 1 will enable
//           the counter.
//
//  Note: All counters are refcounted, that means that a counter will only be
//  disable when its refcount reached zero.
//
// Arguments:
//     session: (INPUT)
//         Handle to the debugging session.
//
//     config: (INPUT)
//         pointer to configuration list as per above.
//
//     count: (INPUT)
//         number of entries in the config list.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Function fails the security check
//
//     RM_INVALID_ARGUMENT:
//         debugging session is invalid or one of the counter lines is invalid.
//         If call returns this value, no action specified by the config list
//         will have taken effect.
//
//     NV_ERR_NOT_SUPPORTED:
//         UvmCounterScopeGlobalSingleGpu is not supported for CUDA 6.0
//
//     NV_ERR_BUSY_RETRY:
//         the debug session is in use by some other thread.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDebugCountersEnable(UvmDebugSession   session,
                                 UvmCounterConfig *config,
                                 unsigned          count);

//------------------------------------------------------------------------------
// UvmDebugGetCounterHandle
//
// Returns handle to a particular counter. This is an opaque handle that the
// implementation uses in order to find your counter, later. This handle can be
// used in subsequent calls to UvmDebugGetCounterVal().
//
// Arguments:
//     session: (INPUT)
//         Handle to the debugging session.
//
//     scope: (INPUT)
//         Scope that will be mapped.
//
//     counterName: (INPUT)
//         Name of the counter in that scope.
//
//     gpu: (INPUT)
//         Gpuid of the scoped GPU. This parameter is ignored in AllGpu scopes.
//
//     pCounterHandle: (OUTPUT)
//         Handle to the counter address.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         Specified scope/gpu pair or session id is invalid
//
//     NV_ERR_NOT_SUPPORTED:
//         UvmCounterScopeGlobalSingleGpu is not supported for CUDA 6.0
//
//     NV_ERR_BUSY_RETRY:
//         debug session is in use by some other thread.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDebugGetCounterHandle(UvmDebugSession  session,
                                   UvmCounterScope  scope,
                                   UvmCounterName   counterName,
                                   NvProcessorUuid  gpu,
                                   NvUPtr          *pCounterHandle);

//------------------------------------------------------------------------------
// UvmDebugGetCounterVal
//
// Returns the counter value specified by the counter name.
//
// Arguments:
//     session: (INPUT)
//         Handle to the debugging session.
//
//     counterHandleArray: (INPUT)
//         Array of counter handles
//
//     handleCount: (INPUT)
//         Number of handles in the pPCounterHandle array.
//
//     counterValArray: (OUTPUT)
//         Array of counter values corresponding to the handles.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         one of the specified handles is invalid.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDebugGetCounterVal(UvmDebugSession     session,
                                NvUPtr             *counterHandleArray,
                                unsigned            handleCount,
                                unsigned long long *counterValArray);

//------------------------------------------------------------------------------
// UvmEventQueueCreate
//
// This call creates an event queue of the given size.
// No events are added in the queue till they are enabled by the user.
// Event queue data is visible to the user even after the target process dies
// if the session is active and queue is not freed.
//
// User doesn't need to serialize multiple UvmEventQueueCreate calls as
// each call creates a new queue state associated with the returned queue
// handle.
//
// Arguments:
//     sessionHandle: (INPUT)
//         Handle to the debugging session.
//
//     queueHandle: (OUTPUT)
//         Handle to created queue.
//
//     queueSize: (INPUT)
//         Size of the event queue buffer in units of UvmEventEntry's.
//         This quantity must be > 1.
//
//     notificationCount: (INPUT)
//         Number of entries after which the user should be notified that
//         there are events to fetch.
//         User is notified when queueEntries >= notification count.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Function fails the security check.
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//     NV_ERR_INSUFFICIENT_RESOURCES:
//         it's not possible to allocate a queue of requested size.
//
//     NV_ERR_BUSY_RETRY:
//         internal resources are blocked by other threads.
//
//     NV_ERR_PID_NOT_FOUND:
//         queue create call is made on a session after the target dies.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventQueueCreate(UvmDebugSession        sessionHandle,
                              UvmEventQueueHandle   *queueHandle,
                              NvS64                  queueSize,
                              NvU64                  notificationCount,
                              UvmEventTimeStampType  timeStampType);

//------------------------------------------------------------------------------
// UvmEventQueueDestroy
//
// This call frees all interal resources associated with the queue, including
// upinning of the memory associated with that queue. Freeing user buffer is
// responsibility of a caller. Event queue might be also destroyed as a side
// effect of destroying a session associated with this queue.
//
// User needs to ensure that a queue handle is not deleted while some other
// thread is using the same queue handle.
//
// Arguments:
//     sessionHandle: (INPUT)
//         Handle to the debugging session.
//
//     queueHandle: (INPUT)
//         Handle to the queue which is to be freed
//
// Error codes:
//     RM_ERR_NOT_PERMITTED:
//         Function fails the security check.
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//     NV_ERR_BUSY_RETRY:
//         internal resources are blocked by other threads.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventQueueDestroy(UvmDebugSession     sessionHandle,
                               UvmEventQueueHandle queueHandle);

//------------------------------------------------------------------------------
// UvmEventEnable
//
// This call enables a particular event type in the event queue.
// All events are disabled by default when a queue is created.
//
// This API does not access the queue state maintained in the user
// library so the user doesn't need to acquire a lock to protect the queue
// state.
//
// Arguments:
//     sessionHandle: (INPUT)
//         Handle to the debugging session.
//
//     queueHandle: (INPUT)
//         Handle to the queue where events are to be enabled
//
//     eventTypeFlags: (INPUT)
//         This field specifies the event types to be enabled. For example:
//         To enable migration events and memory violations: pass flags
//         "UVM_EVENT_ENABLE_MEMORY_VIOLATION |UVM_EVENT_ENABLE_MIGRATION"
//
// Error codes:
//     RM_ERR_NOT_PERMITTED:
//         Function fails the security check.
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//     NV_ERR_PID_NOT_FOUND:
//         this call is made after the target process dies
//
//     NV_ERR_BUSY_RETRY:
//         internal resources are blocked by other threads.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventEnable(UvmDebugSession     sessionHandle,
                         UvmEventQueueHandle queueHandle,
                         unsigned            eventTypeFlags);

//------------------------------------------------------------------------------
// UvmEventDisable
//
// This call disables a particular event type in the queue.
//
// This API does not access the queue state maintained in the user
// library so the user doesn't need to acquire a lock to protect the queue
// state.
//
// Arguments:
//     sessionHandle: (INPUT)
//         Handle to the debugging session.
//
//     queueHandle: (INPUT)
//         Handle to the queue where events are to be enabled
//
//     eventTypeFlags: (INPUT)
//         This field specifies the event types to be enabled
//         For example: To enable migration events and memory violations:
//         pass "UVM_EVENT_ENABLE_MEMORY_VIOLATION |UVM_EVENT_ENABLE_MIGRATION"
//         as flags
//
// Error codes:
//     RM_ERR_NOT_PERMITTED:
//         Function fails the security check.
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//     NV_ERR_PID_NOT_FOUND:
//         this call is made after the target process dies
//
//     NV_ERR_BUSY_RETRY:
//         internal resources are blocked by other threads.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventDisable(UvmDebugSession     sessionHandle,
                          UvmEventQueueHandle queueHandle,
                          unsigned            eventTypeFlags);

//------------------------------------------------------------------------------
// UvmEventWaitOnQueueHandles
//
// User is notified when queueEntries >= notification count.
// This call does a blocking wait for this notification. It returns when
// at least one of the queue handles has events to be fetched or if it timeouts
//
//     This API accesses constant data maintained in the queue state. Hence,
//     the user doesn't need to acquire a lock to protect the queue state.
//
// Arguments:
//     queueHandles: (INPUT)
//         array of queue handles.
//
//     arraySize: (INPUT)
//         number of handles in array.
//
//     timeout: (INPUT)
//         timeout in msec
//
//     pNotificationFlags: (OUTPUT)
//         If a particular queue handle in the input array is notified then
//         the respective bit flag is set in pNotificationFlags.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         one of the queueHandles is invalid.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventWaitOnQueueHandles(UvmEventQueueHandle *queueHandleArray,
                                     unsigned             arraySize,
                                     NvU64                timeout,
                                     unsigned            *pNotificationFlags);

//------------------------------------------------------------------------------
// UvmEventGetNotificationHandles
//
// User is notified when queueEntries >= notification count.
// The user can directly get the queue notification handles rather than using
// a UVM API to wait on queue handles. This helps the user to wait on other
// objects (apart from queue notification) along with queue notification
// handles in the same thread. The user can safely use this call along with the
// library supported wait call UvmEventWaitOnQueueHandles.
//
// This API reads constant data maintained in the queue state. Hence,
// the user doesn't need to acquire a lock to protect the queue state.
//
// Arguments:
//     queueHandles: (INPUT)
//         array of queue handles.
//
//     arraySize: (INPUT)
//         number of handles in array.
//
//     notificationHandles: (OUTPUT)
//         Windows: Output of this call contains an array of 'windows event
//             handles' corresponding to the queue handles passes as input.
//         Linux: All queues belonging to the same process share the same
//             file descriptor(fd) for notification. If the user chooses to use
//             UvmEventGetNotificationHandles then he should check all queues
//             for new events (by calling UvmEventFetch) when notified on
//             the fd.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventGetNotificationHandles(UvmEventQueueHandle  *queueHandleArray,
                                         unsigned              arraySize,
                                         void                **notificationHandleArray);

//------------------------------------------------------------------------------
// UvmEventGetGpuUuidTable
//
// Each migration event entry contains the gpu index to/from where data is
// migrated. This index maps to a corresponding gpu UUID in the gpuUuidTable.
// Using indices saves on the size of each event entry. This API provides the
// gpuIndex to gpuUuid relation to the user.
//
// This API does not access the queue state maintained in the user
// library and so the user doesn't need to acquire a lock to protect the
// queue state.
//
// Arguments:
//     gpuUuidTable: (OUTPUT)
//         The return value is an array of UUIDs. The array index is the
//         corresponding gpuIndex. There can be at max 32 gpus associated with
//         UVM, so array size is 32.
//
//     validCount: (OUTPUT)
//         The system doesn't normally contain 32 GPUs. This field gives the
//         count of entries that are valid in the returned gpuUuidTable.
//
// Error codes:
//     NV_ERR_BUSY_RETRY:
//         internal resources are blocked by other threads.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventGetGpuUuidTable(NvProcessorUuid *gpuUuidTable,
                                  unsigned        *validCount);

//------------------------------------------------------------------------------
// UvmEventFetch
//
// This call is used to fetch the queue entries in a user buffer.
//
// This API updates the queue state. Hence simultaneous calls to fetch/skip
// events should be avoided as that might corrupt the queue state.
//
// Arguments:
//     sessionHandle: (INPUT)
//         Handle to the debugging session.
//
//     queueHandle: (INPUT)
//         queue from where to fetch the events.
//
//     pBuffer: (OUTPUT)
//         Pointer to the buffer where the API will copy the events. User
//         shall ensure the size is enough.
//
//     nEntries: (INPUT/OUTPUT)
//         It provides the maximum number of entries that will be fetched
//         from the queue. If this number is larger than the size of the
//         queue it will be internally capped to that value.
//         As output it returns the actual number of entries copies to the
//         buffer.
//
// Error codes:
//     RM_ERR_NOT_PERMITTED:
//         Function fails the security check.
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//     NV_ERR_INVALID_INDEX:
//         The indices of the queue have been corrupted.
//
//     NV_ERR_BUFFER_TOO_SMALL:
//         The event queue buffer provided by the caller was too small to
//         contain all of the events that occurred during this run.
//         Events were therefore dropped (not recorded).
//         Please re-run with a larger buffer.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventFetch(UvmDebugSession      sessionHandle,
                        UvmEventQueueHandle  queueHandle,
                        UvmEventEntry       *pBuffer,
                        NvU64               *nEntries);

//------------------------------------------------------------------------------
// UvmEventSkipAll
//
// This API drops all event entries from the queue.
//
// This API updates the queue state. Hence simultaneous calls to fetch/
// skip events should be avoided as that might corrupt the queue state.
//
// Arguments:
//     sessionHandle: (INPUT)
//         Handle to the debugging session.
//
//     queueHandle: (INPUT)
//         target queue.
//
// Error codes:
//     RM_ERR_NOT_PERMITTED:
//         Function fails the security check.
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventSkipAll(UvmDebugSession     sessionHandle,
                          UvmEventQueueHandle queueHandle);

//------------------------------------------------------------------------------
// UvmEventQueryTimeStampType
//
// This API returns the type of time stamp used in an event entry for a given
// queue.
//
// This API reads constant data maintained in the queue state. Hence,
// the user doesn't need to acquire a lock to protect the queue state.
//
// Arguments:
//     sessionHandle: (INPUT)
//         Handle to the debugging session.
//
//     queueHandle: (INPUT)
//         target queue.
//
//     timeStampType: (OUTPUT)
//         type of time stamp used in event entry. See UvmEventTimestampType
//         for supported types of time stamps.
//
// Error codes:
//     RM_ERR_NOT_PERMITTED:
//         Function fails the security check.
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//------------------------------------------------------------------------------
NV_STATUS UvmEventQueryTimeStampType(UvmDebugSession        sessionHandle,
                                     UvmEventQueueHandle    queueHandle,
                                     UvmEventTimeStampType *timeStampType);

//------------------------------------------------------------------------------
// UvmDebugAccessMemory
//
// This call can be used by the debugger to read/write memory range. UVM driver
// may not be aware of all the pages in this range. A bit per page is set by the
// driver if it is read/written by UVM.
//
// Arguments:
//     session: (INPUT)
//         Handle to the debugging session.
//
//     baseAddress: (INPUT)
//         base address from where memory is to be accessed
//
//     sizeInBytes: (INPUT)
//         Number of bytes to be accessed
//
//     accessType: (INPUT)
//         Read or write access request
//
//     buffer: (INPUT/OUTPUT)
//         This buffer would be read or written to by the driver.
//         User needs to allocate a big enough buffer to fit sizeInBytes.
//
//     isBitmaskSet: (INPUT/OUTPUT)
//         Set to 1, if any field in bitmask is set
//         NULL(INPUT) if unused
//
//     bitmask: (INPUT/OUTPUT)
//         One bit per page is set if UVM reads or writes to it.
//         User should allocate a bitmask big enough to fit one bit per page
//         covered by baseAddress + sizeInBytes:
//         (baseAlignmentBytes + sizeInBytes + pageSize - 1)/pageSize number
//         of bits.
//         NULL(IN) if unused.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         One of the arguments is invalid.
//
//------------------------------------------------------------------------------
NV_STATUS UvmDebugAccessMemory(UvmDebugSession     session,
                               void               *baseAddress,
                               NvU64               sizeInBytes,
                               UvmDebugAccessType  accessType,
                               void               *buffer,
                               NvBool             *isBitmaskSet,
                               NvU64              *bitmask);

//
// Uvm Tools uvm API
//


//------------------------------------------------------------------------------
// UvmToolsCreateSession
//
// Creates a handle for a tools session.
//
// When the client initializes, it will pass a duplicated Uvm file handle from
// target's process UvmGetFileDescriptor API, e.g. by calling DuplicateHandle,
// dup2, share file descriptor over Unix Socket Domains. Returned session
// handle is required to create other Tool's objects, e.g. events, counters.
//
// In order to guarantee that session persists the lifetime of a target process,
// callee is responsible for passing a duplicate file descriptor. This is also
// required for correctness in case of out-of-process session.
//
// Passing non duplicated Uvm file handle results in undefined behaviour. The
// least that you should expect is that all your session related objects will
// become useless once target process closes Uvm file handle.
//
//
// There are security requirements for this call to be successful. Fortunately,
// after validating a file descriptor, one of the following conditions must
// hold:
// 1.  The session owner is running as an elevated user
// 2.  The session owner and target belong to the same user and the
//     session owner is at least as privileged as the target.
//
// Arguments:
//     fd: (INPUT)
//         Duplicated file handle from target process.
//
//     session: (OUTPUT)
//         Handle to the tools session associated to fd above.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         fd is either closed or points to non uvm device.
//
//     NV_ERR_NO_MEMORY:
//         Internal memory allocation failed.
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsCreateSession(UvmFileDescriptor      fd,
                                UvmToolsSessionHandle *session);

//------------------------------------------------------------------------------
// UvmToolsDestroySession
//
// Destroys a tools session. This also has a side-effect of closing fd
// associated with this session during UvmToolsCreateSession.
//
// All resources associated with this session (counters, event queues) are also
// destroyed.
//
// Arguments:
//     session: (INPUT)
//         Handle associated with a Tool's session.
//
// Error codes:
//     NV_ERR_INVALID_ARGUMENT:
//         session handle does not refer to a valid session.
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsDestroySession(UvmToolsSessionHandle session);

//
// Events subsystem
//
// Events subsystem is useful for a tools process to track target process
// behaviour. Every event refers to a single process using Unified memory.
//
// The most typical use case is as follows:
// 1. Create event Queue using UvmToolsCreateEventQueue
// 2. Start capture of interesting event types using
//    UvmToolsEventQueueEnableEvents
// 3. poll / Loop using Get/Put pointer
// - Consume existing events from user's buffer
// - exit loop based on some condition (e.g. timeout, target process exit)
// - pause (Stop) capture of some of the events
// 4. Destroy event Queue using UvmToolsDestroyEventQueue
//


NvLength UvmToolsGetEventControlSize(void);

NvLength UvmToolsGetEventEntrySize(void);

NvLength UvmToolsGetNumberOfCounters(void);

//------------------------------------------------------------------------------
// UvmToolsCreateEventQueue
//
// This call creates an event queue that can hold the given number of events.
// All events are disabled by default. Event queue data persists lifetime of the
// target process.
//
// Arguments:
//     session: (INPUT)
//         Handle to the tools session.
//
//     event_buffer: (INPUT)
//         User allocated buffer. Must be page-aligned. Must be large enough to
//         hold at least event_buffer_size events. Gets pinned until queue is
//         destroyed.
//
//     event_buffer_size: (INPUT)
//         Size of the event queue buffer in units of UvmEventEntry's. Must be
//         a power of two, and greater than 1.
//
//     event_control (INPUT)
//         User allocated buffer. Must be page-aligned. Must be large enough to
//         hold UvmToolsEventControlData (although single page-size allocation
//         should be more than enough). One could call
//         UvmToolsGetEventControlSize() function to find out current size of
//         UvmToolsEventControlData. Gets pinned until queue is destroyed.
//
//     queue: (OUTPUT)
//         Handle to the created queue.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Session handle does not refer to a valid session
//
//     NV_ERR_INVALID_ARGUMENT:
//         One of the parameters: event_buffer, event_buffer_size, event_control
//         is not valid
//
//     NV_ERR_INSUFFICIENT_RESOURCES:
//         There could be multiple reasons for this error. One would be that it's
//         not possible to allocate a queue of requested size. Another would be
//         that either event_buffer or event_control memory couldn't be pinned
//         (e.g. because of OS limitation of pinnable memory). Also it could not
//         have been possible to create UvmToolsEventQueueDescriptor.
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsCreateEventQueue(UvmToolsSessionHandle     session,
                                   void                     *event_buffer,
                                   NvLength                  event_buffer_size,
                                   void                     *event_control,
                                   UvmToolsEventQueueHandle *queue);

UvmToolsEventQueueDescriptor UvmToolsGetEventQueueDescriptor(UvmToolsEventQueueHandle queue);


//------------------------------------------------------------------------------
// UvmToolsSetNotificationThreshold
//
// Sets a custom notification threshold in number of events for a given queue.
// Polling subsystem will notify user about this queue if and only if number
// of unconsumed events is greater or equal notification_threshold. Default
// threshold upon creating an event queue is floor(N / 2), where N represents
// maximum number of events that this queue can fit.
//
// Consequently, if notifications_threshold is greater than queue size, there
// will be no notification.
//
// Arguments:
//     queue: (INPUT)
//         Handle to the queue, for which events are supposed to be enabled
//
//     notification_threshold: (INPUT)
//         A new threshold, in number of events, to be set for this queue.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Event Queue might be corrupted (associated session is not valid).
//
//     NV_ERR_INVALID_ARGUMENT:
//         Queue handle does not refer to a valid queue.
//------------------------------------------------------------------------------
NV_STATUS UvmToolsSetNotificationThreshold(UvmToolsEventQueueHandle queue,
                                           NvLength notification_threshold);

//------------------------------------------------------------------------------
// UvmToolsDestroyEventQueue
//
// Destroys all internal resources associated with the queue. It unpinns the
// buffers provided in UvmToolsCreateEventQueue. Event Queue is also auto
// destroyed when corresponding session gets destroyed.
//
// Arguments:
//     queue: (INPUT)
//         Handle to the queue to be destroyed
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Event Queue might be corrupted (associated session is not valid).
//
//     NV_ERR_INVALID_ARGUMENT:
//         Queue handle does not refer to a valid queue.
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsDestroyEventQueue(UvmToolsEventQueueHandle queue);

//------------------------------------------------------------------------------
// UvmEventQueueEnableEvents
//
// This call enables a particular event type in the event queue. All events are
// disabled by default. Any event type is considered listed if and only if it's
// corresponding value is equal to 1 (in other words, bit is set). Disabled
// events listed in eventTypeFlags are going to be enabled. Enabled events and
// events not listed in eventTypeFlags are not affected by this call.
//
// It is not an error to call this function multiple times with the same
// arguments.
//
// Arguments:
//     queue: (INPUT)
//         Handle to the queue, for which events are supposed to be enabled
//
//     eventTypeFlags: (INPUT)
//         This bit field specifies the event types to be enabled. Events not
//         specified in this field do not change their state. For example to
//         enable migration and memory violations events pass flags
//         "UVM_EVENT_ENABLE_MEMORY_VIOLATION | UVM_EVENT_ENABLE_MIGRATION"
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Event Queue might be corrupted (associated session is not valid).
//
//     NV_ERR_INVALID_ARGUMENT:
//         Queue handle does not refer to a valid queue.
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsEventQueueEnableEvents(UvmToolsEventQueueHandle queue,
                                         NvU64                    eventTypeFlags);

//------------------------------------------------------------------------------
// UvmToolsEventQueueDisableEvents
//
// This call disables a particular event type in the event queue. Any event type
// is considered listed if and only if it's corresponding value is equal to 1
// (in other words, bit is set). Enabled events listed in eventTypeFlags are
// going to be disabled. Disabled events and events not listed in eventTypeFlags
// are not affected by this call.
//
// It is not an error to call this function multiple times with the same
// arguments.
//
// Arguments:
//     queue: (INPUT)
//         Handle to the queue, for which events are supposed to be enabled
//
//     eventTypeFlags: (INPUT)
//         This bit field specifies the event types to be disabled. Events not
//         specified in this field do not change their state. For example to
//         disable migration and memory violations events pass flags
//         "UVM_EVENT_ENABLE_MEMORY_VIOLATION | UVM_EVENT_ENABLE_MIGRATION"
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Event Queue might be corrupted (associated session is not valid).
//
//     NV_ERR_INVALID_ARGUMENT:
//         Queue handle does not refer to a valid event queue.
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsEventQueueDisableEvents(UvmToolsEventQueueHandle queue,
                                          NvU64                    eventTypeFlags);


//------------------------------------------------------------------------------
// UvmToolsCreateProcessAggregateCounters
//
// Creates the counters structure for tracking aggregate process counters.
// These counters are enabled by default.
//
// Counters position follows the layout of the memory that UVM driver decides to
// use. To obtain particular counter value, user should perform consecutive
// atomic reads at a a given buffer + offset address.
//
// It is not defined what is the initial value of a counter. User should rely on
// a difference between each snapshot.
//
// Arguments:
//     session: (INPUT)
//         Handle to the tools session.
//
//     counters_buffer : (INPUT)
//         User allocated buffer. Must be aligned to the OS's page aligned. Must
//         be large enough to hold all possible counter types. In practice, 4kB
//         system page (minimal granurality) should be sufficent. This memory
//         gets pinned until counters are destroyed.
//
//     counters: (OUTPUT)
//         Handle to the created counters.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Provided session is not valid
//
//     NV_ERR_INSUFFICIENT_RESOURCES
//         There could be multiple reasons for this error. One would be that it's
//         not possible to allocate counters structure. Another would be that
//         either event_buffer or event_control memory couldn't be pinned
//         (e.g. because of OS limitation of pinnable memory)
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsCreateProcessAggregateCounters(UvmToolsSessionHandle   session,
                                                 void                   *counters_buffer,
                                                 UvmToolsCountersHandle *counters);

//------------------------------------------------------------------------------
// UvmToolsCreateProcessorCounters
//
// Creates the counters structure for tracking per-process counters.
// These counters are disabled by default.
//
// Counters position follows the layout of the memory that UVM driver decides to
// use. To obtain particular counter value, user should perform consecutive
// atomic reads at a a given buffer + offset address.
//
// It is not defined what is the initial value of a counter. User should rely on
// a difference between each snapshot.
//
// Arguments:
//     session: (INPUT)
//         Handle to the tools session.
//
//     counters_buffer : (INPUT)
//         User allocated buffer. Must be aligned to the OS's page aligned. Must
//         be large enough to hold all possible counter types. In practice, 4kB
//         system page should be sufficent. This memory gets pinned until
//         counters are destroyed.
//
//     processorUuid: (INPUT)
//        UUID of the resource, for which counters will provide statistic data.
//
//     counters: (OUTPUT)
//         Handle to the created counters.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         session handle does not refer to a valid tools session
//
//     NV_ERR_INSUFFICIENT_RESOURCES
//         There could be multiple reasons for this error. One would be that it's
//         not possible to allocate counters structure. Another would be that
//         either event_buffer or event_control memory couldn't be pinned
//         (e.g. because of OS limitation of pinnable memory)
//
//     NV_ERR_INVALID_ARGUMENT
//         processorUuid does not refer to any known resource in UVM driver
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsCreateProcessorCounters(UvmToolsSessionHandle   session,
                                          void                   *counters_buffer,
                                          const NvProcessorUuid  *processorUuid,
                                          UvmToolsCountersHandle *counters);

//------------------------------------------------------------------------------
// UvmToolsDestroyCounters
//
// Destroys all internal resources associated with this counters structure.
// It unpinns the buffer provided in UvmToolsCreate*Counters. Counters structure
// also gest destroyed when corresponding session is destroyed.
//
// Arguments:
//     counters: (INPUT)
//         Handle to the counters structure.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         State of the counters has been corrupted.
//
//     NV_ERR_INVALID_ARGUMENT:
//         Counters handle does not refer to a valid Counters structure.
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsDestroyCounters(UvmToolsCountersHandle counters);

//------------------------------------------------------------------------------
// UvmToolsEnableCounters
//
// This call enables certain counter types in the counters structure. Any
// counter type is considered listed if and only if it's corresponding value is
// equal to 1 (in other words, bit is set). Disabled counter types listed in
// counterTypeFlags are going to be enabled. Already enabled counter types and
// counter types not listed in counterTypeFlags are not affected by this call.
//
// It is not an error to call this function multiple times with the same
// arguments.
//
// Arguments:
//     counters: (INPUT)
//         Handle to the counters structure.
//
//     counterTypeFlags: (INPUT)
//         This bit field specifies the counter types to be enabled.
//         For example, to enable faults number accounting and number of bytes
//         transferred into a given resource (or aggregate) pass flags
//         "UVM_COUNTER_ENABLE_FAULTS_NUMBER |
//          UVM_COUNTER_ENABLE_BYTES_TRANSFERRED_IN"
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Counters structure mighe be corrupted (associated session is not
//         valid).
//
//     NV_ERR_INVALID_ARGUMENT:
//         Counters handle does not refer to a valid counters structure.
//------------------------------------------------------------------------------
NV_STATUS UvmToolsEnableCounters(UvmToolsCountersHandle counters,
                                 NvU64                  counterTypeFlags);

//------------------------------------------------------------------------------
// UvmToolsDisableCounters
//
// This call disables certain counter types in the counters structure. Any
// counter type is considered listed if and only if it's corresponding value is
// equal to 1 (in other words, bit is set). Enabled counter types listed in
// counterTypeFlags are going to be disabled. Already disabled counter types and
// counter types not listed in counterTypeFlags are not affected by this call.
//
// It is not an error to call this function multiple times with the same
// arguments.
//
// Arguments:
//     counters: (INPUT)
//         Handle to the counters structure.
//
//     counterTypeFlags: (INPUT)
//         This bit field specifies the counter types to be disabled.
//         For example, to disable faults number accounting and number of bytes
//         transferred into a given resource (or aggregate) pass flags
//         "UVM_COUNTER_ENABLE_FAULTS_NUMBER |
//          UVM_COUNTER_ENABLE_BYTES_TRANSFERRED_IN"
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Counters structure mighe be corrupted (associated session is not
//         valid).
//
//     NV_ERR_INVALID_ARGUMENT:
//         Counters handle does not refer to a valid counters structure.
//------------------------------------------------------------------------------
NV_STATUS UvmToolsDisableCounters(UvmToolsCountersHandle counters,
                                  NvU64                  counterTypeFlags);

//------------------------------------------------------------------------------
// UvmToolsReadProcessMemory
//
// Reads up to size bytes from a given target process's virtual address.
// If size is 0, function should successfully return size of the largest size
// that can be read starting at a given target process's virtual memory. This
// might be used to discover size of user's allocation.
//
// Upon successful execution and size greater than 0, user should have a copy of
// target's process memory in a given buffer. Result is unspecified in case of
// In-process scenario when targetVa address + size overlaps with buffer + size.
//
// This is essentially a UVM version of RM ctrl call
// NV83DE_CTRL_CMD_DEBUG_READ_MEMORY. For implementation constraints (and more
// information), please refer to the documentation:
// //sw/docs/resman/components/compute/UVM/subsystems/UVM_8_Tools_API_Design.docx
//
// Arguments:
//     session: (INPUT)
//         Handle to the tools session.
//
//     buffer: (INPUT)
//         User buffer (destination) address, where requested memory shall be
//         copied.
//
//     size: (INPUT)
//         Number of bytes requested to be copied. If user's buffer is not large
//         enough to fit size bytes, result is unspecified. If this is 0,
//         function should return largest chunk of memory available to read.
//
//     targetVa: (INPUT)
//         Target process's (source) address, from which memory should be
//         copied.
//
//     bytes_read: (OUTPUT)
//         Either number of bytes successfully read or the largest chunk of
//         memory available to read, depending on size parameter.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         session handle does not refer to a valid tools session
//
//     NV_ERR_INVALID_ADDRESS:
//         UVM driver has no knowledge of targetVa address.
//
//     NV_ERR_INVALID_ARGUMENT:
//         Read spans more than a single target process allocation.
//
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsReadProcessMemory(UvmToolsSessionHandle  session,
                                    void                  *buffer,
                                    NvLength               size,
                                    void                  *targetVa,
                                    NvLength              *bytes_read);

//------------------------------------------------------------------------------
// UvmToolsWriteProcessMemory
//
// Writes up to size bytes from a given target process's virtual address.
// If size is 0, function should successfully return size of the largest size
// that can be written starting at a given target process's virtual address.
// This might be used to discover size of user's allocation.
//
// Upon successful execution and size greater than 0, target process should have
// a copy of buffer starting at targetVa address. Result is unspecified in case
// of In-process scenario when targetVa address + size overlaps with
// buffer + size.
//
// This is essentially a UVM version of RM ctrl call
// NV83DE_CTRL_CMD_DEBUG_READ_MEMORY. For implementation constraints (and more
// information), please refer to the documentation:
// //sw/docs/resman/components/compute/UVM/subsystems/UVM_8_Tools_API_Design.docx
//
// Arguments:
//     session: (INPUT)
//         Handle to the tools session.
//
//     buffer: (INPUT)
//         User buffer (source) address, from which requested memory shall be
//         copied.
//
//     size: (INPUT)
//         Number of bytes requested to be copied. If user's buffer is not large
//         enough to fit size bytes, result is unspecified. If this is 0,
//         function should return largest chunk of memory available to write.
//
//     targetVa: (INPUT)
//         Target process's (destination) address, where memory should be
//         copied.
//
//     bytes_read: (OUTPUT)
//         Either number of bytes successfully written or the largest chunk of
//         memory available to write, depending on size parameter.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         session handle does not refer to a valid tools session
//
//     NV_ERR_INVALID_ADDRESS:
//         UVM driver has no knowledge of targetVa address.
//
//     NV_ERR_INVALID_ARGUMENT:
//         Write spans more than a single target process allocation.
//
//------------------------------------------------------------------------------
NV_STATUS UvmToolsWriteProcessMemory(UvmToolsSessionHandle  session,
                                     void                  *buffer,
                                     NvLength               size,
                                     void                  *targetVa,
                                     NvLength              *bytes_read);

//------------------------------------------------------------------------------
// UvmToolsGetProcessorUuidTable
//
// Populate a table with the UUIDs of all the currently registered processors
// in the target process.  When a GPU is registered, it is added to the table.
// When a GPU is unregistered, it is removed.  As long as a GPU remains registered,
// its index in the table does not change.  New registrations obtain the first
// unused index.
//
// Arguments:
//     session: (INPUT)
//         Handle to the tools session.
//
//     table: (OUTPUT)
//         Array of processor UUIDs, including the CPU's UUID which is always
//         at index zero.  The srcIndex and dstIndex fields of the
//         UvmEventMigrationInfo struct index this array.  Unused indices will
//         have a UUID of zero.
//
//     count: (OUTPUT)
//         Set by UVM to the number of UUIDs written, including any gaps in
//         the table due to unregistered GPUs.
//
// Error codes:
//     NV_ERR_INVALID_ADDRESS:
//         writing to table failed.
//------------------------------------------------------------------------------
NV_STATUS UvmToolsGetProcessorUuidTable(UvmToolsSessionHandle  session,
                                        NvProcessorUuid       *table,
                                        NvLength              *count);

//------------------------------------------------------------------------------
// UvmToolsFlushEvents
//
// Some events, like migrations, which have end timestamps are not immediately
// submitted to queues when they are completed.  This call enqueues any
// completed but unenqueued events associated with the session.
//
// Arguments:
//     session: (INPUT)
//         Handle to the tools session.
//
// Error codes:
//     NV_ERR_INSUFFICIENT_PERMISSIONS:
//         Session handle does not refer to a valid session
//------------------------------------------------------------------------------
NV_STATUS UvmToolsFlushEvents(UvmToolsSessionHandle session);

#ifdef __cplusplus
}
#endif

#endif // _UVM_H_