Drivers: hv: Remove deprecated hv_fcopy declarations

There are lingering hv_fcopy declarations which do not have definitions.
The fcopy driver was removed in commit ec314f61e4fc ("Drivers: hv: Remov

Drivers: hv: Remove deprecated hv_fcopy declarations

There are lingering hv_fcopy declarations which do not have definitions.
The fcopy driver was removed in commit ec314f61e4fc ("Drivers: hv: Remove
fcopy driver").

Therefore, remove the hv_fcopy declarations which are no longer needed
or defined.

Fixes: ec314f61e4fc ("Drivers: hv: Remove fcopy driver")
Signed-off-by: Rachel Menge <rachelmenge@linux.microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Link: https://lore.kernel.org/r/20240620225040.700563-1-rachelmenge@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240620225040.700563-1-rachelmenge@linux.microsoft.com>

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Drivers: hv: vmbus: Add utility function for querying ring size

Add a function to query for the preferred ring buffer size of VMBus
device. This will allow the drivers (eg. UIO) to allocate the most

Drivers: hv: vmbus: Add utility function for querying ring size

Add a function to query for the preferred ring buffer size of VMBus
device. This will allow the drivers (eg. UIO) to allocate the most
optimized ring buffer size for devices.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Link: https://lore.kernel.org/r/1711788723-8593-2-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor

The post_msg_page was removed in
commit 9a6b1a170ca8 ("Drivers: hv: vmbus: Remove the per-CPU post_msg_page")

However

Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor

The post_msg_page was removed in
commit 9a6b1a170ca8 ("Drivers: hv: vmbus: Remove the per-CPU post_msg_page")

However, it turns out that we need to bring it back, but only for a TDX VM
with the paravisor: in such a VM, the hyperv_pcpu_input_arg is not decrypted,
but the HVCALL_POST_MESSAGE in such a VM needs a decrypted page as the
hypercall input page: see the comments in hyperv_init() for a detailed
explanation.

Except for HVCALL_POST_MESSAGE and HVCALL_SIGNAL_EVENT, the other hypercalls
in a TDX VM with the paravisor still use hv_hypercall_pg and must use the
hyperv_pcpu_input_arg (which is encrypted in such a VM), when a hypercall
input page is used.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230824080712.30327-8-decui@microsoft.com

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Drivers: hv: vmbus: Remove the per-CPU post_msg_page

The post_msg_page was introduced in 2014 in
commit b29ef3546aec ("Drivers: hv: vmbus: Cleanup hv_post_message()")

Commit 68bb7bfb7985 ("X86/Hype

Drivers: hv: vmbus: Remove the per-CPU post_msg_page

The post_msg_page was introduced in 2014 in
commit b29ef3546aec ("Drivers: hv: vmbus: Cleanup hv_post_message()")

Commit 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments") introduced
the hyperv_pcpu_input_arg in 2018, which can be used in hv_post_message().

Remove post_msg_page to simplify the code a little bit.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Jinank Jain <jinankjain@linux.microsoft.com>
Link: https://lore.kernel.org/r/20230408213441.15472-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vmbus: Remove second mapping of VMBus monitor pages

With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), creating a second kernel virtua

Drivers: hv: vmbus: Remove second mapping of VMBus monitor pages

With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), creating a second kernel virtual
mapping for shared memory is no longer necessary. Everything needed
for the transition to shared is handled by set_memory_decrypted().

As such, remove the code to create and manage the second
mapping for VMBus monitor pages. Because set_memory_decrypted()
and set_memory_encrypted() are no-ops in normal VMs, it's
not even necessary to test for being in a Confidential VM
(a.k.a., "Isolation VM").

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/1679838727-87310-9-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vm_bus: Handle vmbus rescind calls after vmbus is suspended

Add a flag to indicate that the vmbus is suspended so we should ignore
any offer message. Add a new work_queue for rescind ms

Drivers: hv: vm_bus: Handle vmbus rescind calls after vmbus is suspended

Add a flag to indicate that the vmbus is suspended so we should ignore
any offer message. Add a new work_queue for rescind msg, so we could drain
it along with other offer work_queues upon suspension.
It was observed that in some hibernation related scenario testing, after
vmbus_bus_suspend() we get rescind offer message for the vmbus. This would
lead to processing of a rescind message for a channel that has already been
suspended.

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220711041147.GA5569@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vmbus: Introduce vmbus_sendpacket_getid()

The function can be used to send a VMbus packet and retrieve the
corresponding transaction ID. It will be used by hv_pci.

No functional chang

Drivers: hv: vmbus: Introduce vmbus_sendpacket_getid()

The function can be used to send a VMbus packet and retrieve the
corresponding transaction ID. It will be used by hv_pci.

No functional change.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220419122325.10078-4-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: Rename 'alloced' to 'allocated'

'Alloced' is not a real word and only saves us two letters, let's
use 'allocated' instead.

No functional change intended.

Signed-off-by: Vitaly Kuznets

Drivers: hv: Rename 'alloced' to 'allocated'

'Alloced' is not a real word and only saves us two letters, let's
use 'allocated' instead.

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220128103412.3033736-2-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vmbus: Add SNP support for VMbus channel initiate message

The monitor pages in the CHANNELMSG_INITIATE_CONTACT msg are shared
with host in Isolation VM and so it's necessary to use hvca

Drivers: hv: vmbus: Add SNP support for VMbus channel initiate message

The monitor pages in the CHANNELMSG_INITIATE_CONTACT msg are shared
with host in Isolation VM and so it's necessary to use hvcall to set
them visible to host. In Isolation VM with AMD SEV SNP, the access
address should be in the extra space which is above shared gpa
boundary. So remap these pages into the extra address(pa +
shared_gpa_boundary).

Introduce monitor_pages_original[] in the struct vmbus_connection
to store monitor page virtual address returned by hv_alloc_hyperv_
zeroed_page() and free monitor page via monitor_pages_original in
the vmbus_disconnect(). The monitor_pages[] is to used to access
monitor page and it is initialized to be equal with monitor_pages_
original. The monitor_pages[] will be overridden in the isolation VM
with va of extra address. Introduce monitor_pages_pa[] to store
monitor pages' physical address and use it to populate pa in the
initiate msg.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-9-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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hyperv/vmbus: include linux/bitops.h

On arm64 randconfig builds, hyperv sometimes fails with this
error:

In file included from drivers/hv/hv_trace.c:3:
In file included from drivers/hv/hyperv_vmbus

hyperv/vmbus: include linux/bitops.h

On arm64 randconfig builds, hyperv sometimes fails with this
error:

In file included from drivers/hv/hv_trace.c:3:
In file included from drivers/hv/hyperv_vmbus.h:16:
In file included from arch/arm64/include/asm/sync_bitops.h:5:
arch/arm64/include/asm/bitops.h:11:2: error: only <linux/bitops.h> can be included directly
In file included from include/asm-generic/bitops/hweight.h:5:
include/asm-generic/bitops/arch_hweight.h:9:9: error: implicit declaration of function '__sw_hweight32' [-Werror,-Wimplicit-function-declaration]
include/asm-generic/bitops/atomic.h:17:7: error: implicit declaration of function 'BIT_WORD' [-Werror,-Wimplicit-function-declaration]

Include the correct header first.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20211018131929.2260087-1-arnd@kernel.org
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer

Pointers to ring-buffer packets sent by Hyper-V are used within the
guest VM. Hyper-V can send packets with erroneous values o

Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer

Pointers to ring-buffer packets sent by Hyper-V are used within the
guest VM. Hyper-V can send packets with erroneous values or modify
packet fields after they are processed by the guest. To defend
against these scenarios, return a copy of the incoming VMBus packet
after validating its length and offset fields in hv_pkt_iter_first().
In this way, the packet can no longer be modified by the host.

Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210408161439.341988-1-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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drivers/hv: remove obsolete TODO and fix misleading typo in comment

Removes an obsolete TODO in the VMBus module and fixes a misleading typo
in the comment for the macro MAX_NUM_CHANNELS, where two

drivers/hv: remove obsolete TODO and fix misleading typo in comment

Removes an obsolete TODO in the VMBus module and fixes a misleading typo
in the comment for the macro MAX_NUM_CHANNELS, where two digits have been
twisted.

Signed-off-by: Stefan Eschenbacher <stefan.eschenbacher@fau.de>
Co-developed-by: Max Stolze <max.stolze@fau.de>
Signed-off-by: Max Stolze <max.stolze@fau.de>
Link: https://lore.kernel.org/r/20201206104850.24843-1-stefan.eschenbacher@fau.de
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening

Currently, VMbus drivers use pointers into guest memory as request IDs
for interactions with Hyper-V. To be more robust in

Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening

Currently, VMbus drivers use pointers into guest memory as request IDs
for interactions with Hyper-V. To be more robust in the face of errors
or malicious behavior from a compromised Hyper-V, avoid exposing
guest memory addresses to Hyper-V. Also avoid Hyper-V giving back a
bad request ID that is then treated as the address of a guest data
structure with no validation. Instead, encapsulate these memory
addresses and provide small integers as request IDs.

Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20201109100402.8946-2-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vmbus: Resolve more races involving init_vp_index()

init_vp_index() uses the (per-node) hv_numa_map[] masks to record the
CPUs allocated for channel interrupts at a given time, and dist

Drivers: hv: vmbus: Resolve more races involving init_vp_index()

init_vp_index() uses the (per-node) hv_numa_map[] masks to record the
CPUs allocated for channel interrupts at a given time, and distribute
the performance-critical channels across the available CPUs: in part.,
the mask of "candidate" target CPUs in a given NUMA node, for a newly
offered channel, is determined by XOR-ing the node's CPU mask and the
node's hv_numa_map. This operation/mechanism assumes that no offline
CPUs is set in the hv_numa_map mask, an assumption that does not hold
since such mask is currently not updated when a channel is removed or
assigned to a different CPU.

To address the issues described above, this adds hooks in the channel
removal path (hv_process_channel_removal()) and in target_cpu_store()
in order to clear, resp. to update, the hv_numa_map[] masks as needed.
This also adds a (missed) update of the masks in init_vp_index() (cf.,
e.g., the memory-allocation failure path in this function).

Like in the case of init_vp_index(), such hooks require to determine
if the given channel is performance critical. init_vp_index() does
this by parsing the channel's offer, it can not rely on the device
data structure (device_obj) to retrieve such information because the
device data structure has not been allocated/linked with the channel
by the time that init_vp_index() executes. A similar situation may
hold in hv_is_alloced_cpu() (defined below); the adopted approach is
to "cache" the device type of the channel, as computed by parsing the
channel's offer, in the channel structure itself.

Fixes: 7527810573436f ("Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type")
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200522171901.204127-3-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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hv_utils: Always execute the fcopy and vss callbacks in a tasklet

The fcopy and vss callback functions could be running in a tasklet
at the same time they are called in hv_poll_channel(). Current c

hv_utils: Always execute the fcopy and vss callbacks in a tasklet

The fcopy and vss callback functions could be running in a tasklet
at the same time they are called in hv_poll_channel(). Current code
serializes the invocations of these functions, and their accesses to
the channel ring buffer, by sending an IPI to the CPU that is allowed
to access the ring buffer, cf. hv_poll_channel(). This IPI mechanism
becomes infeasible if we allow changing the CPU that a channel will
interrupt. Instead modify the callback wrappers to always execute
the fcopy and vss callbacks in a tasklet, thus mirroring the solution
for the kvp callback functions adopted since commit a3ade8cc474d8
("HV: properly delay KVP packets when negotiation is in progress").
This will ensure that the callback function can't run on two CPUs at
the same time.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-6-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels

When Hyper-V sends an interrupt to the guest, the guest has to figure
out which channel the interrupt is associa

Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels

When Hyper-V sends an interrupt to the guest, the guest has to figure
out which channel the interrupt is associated with. Hyper-V sets a bit
in a memory page that is shared with the guest, indicating a particular
"relid" that the interrupt is associated with. The current Linux code
then uses a set of per-CPU linked lists to map a given "relid" to a
pointer to a channel structure.

This design introduces a synchronization problem if the CPU that Hyper-V
will interrupt for a certain channel is changed. If the interrupt comes
on the "old CPU" and the channel was already moved to the per-CPU list
of the "new CPU", then the relid -> channel mapping will fail and the
interrupt is dropped. Similarly, if the interrupt comes on the new CPU
but the channel was not moved to the per-CPU list of the new CPU, then
the mapping will fail and the interrupt is dropped.

Relids are integers ranging from 0 to 2047. The mapping from relids to
channel structures can be done by setting up an array with 2048 entries,
each entry being a pointer to a channel structure (hence total size ~16K
bytes, which is not a problem). The array is global, so there are no
per-CPU linked lists to update. The array can be searched and updated
by loading from/storing to the array at the specified index. With no
per-CPU data structures, the above mentioned synchronization problem is
avoided and the relid2channel() function gets simpler.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-4-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: vmbus: Always handle the VMBus messages on CPU0

A Linux guest have to pick a "connect CPU" to communicate with the
Hyper-V host. This CPU can not be taken offline because Hyper-V does

Drivers: hv: vmbus: Always handle the VMBus messages on CPU0

A Linux guest have to pick a "connect CPU" to communicate with the
Hyper-V host. This CPU can not be taken offline because Hyper-V does
not provide a way to change that CPU assignment.

Current code sets the connect CPU to whatever CPU ends up running the
function vmbus_negotiate_version(), and this will generate problems if
that CPU is taken offine.

Establish CPU0 as the connect CPU, and add logics to prevents the
connect CPU from being taken offline. We could pick some other CPU,
and we could pick that "other CPU" dynamically if there was a reason to
do so at some point in the future. But for now, #defining the connect
CPU to 0 is the most straightforward and least complex solution.

While on this, add inline comments explaining "why" offer and rescind
messages should not be handled by a same serialized work queue.

Suggested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20200406001514.19876-2-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Drivers: hv: check VMBus messages lengths

VMBus message handlers (channel_message_table) receive a pointer to
'struct vmbus_channel_message_header' and cast it to a structure of their
choice, which

Drivers: hv: check VMBus messages lengths

VMBus message handlers (channel_message_table) receive a pointer to
'struct vmbus_channel_message_header' and cast it to a structure of their
choice, which is sometimes longer than the header. We, however, don't check
that the message is long enough so in case hypervisor screws up we'll be
accessing memory beyond what was allocated for temporary buffer.

Previously, we used to always allocate and copy 256 bytes from message page
to temporary buffer but this is hardly better: in case the message is
shorter than we expect we'll be trying to consume garbage as some real
data and no memory guarding technique will be able to identify an issue.

Introduce 'min_payload_len' to 'struct vmbus_channel_message_table_entry'
and check against it in vmbus_on_msg_dpc(). Note, we can't require the
exact length as new hypervisor versions may add extra fields to messages,
we only check that the message is not shorter than we expect.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104326.45361-1-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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hv: hyperv_vmbus.h: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism t

hv: hyperv_vmbus.h: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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hv_utils: Add the support of hibernation

Add util_pre_suspend() and util_pre_resume() for some hv_utils devices
(e.g. kvp/vss/fcopy), because they need special handling before
util_suspend() calls v

hv_utils: Add the support of hibernation

Add util_pre_suspend() and util_pre_resume() for some hv_utils devices
(e.g. kvp/vss/fcopy), because they need special handling before
util_suspend() calls vmbus_close().

For kvp, all the possible pending work items should be cancelled.

For vss and fcopy, some extra clean-up needs to be done, i.e. fake a
THAW message for hv_vss_daemon and fake a CANCEL_FCOPY message for
hv_fcopy_daemon, otherwise when the VM resums back, the daemons
can end up in an inconsistent state (i.e. the file systems are
frozen but will never be thawed; the file transmitted via fcopy
may not be complete). Note: there is an extra patch for the daemons:
"Tools: hv: Reopen the devices if read() or write() returns errors",
because the hv_utils driver can not guarantee the whole transaction
finishes completely once util_suspend() starts to run (at this time,
all the userspace processes are frozen).

util_probe() disables channel->callback_event to avoid the race with
the channel callback.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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drivers: hv: vmbus: Introduce latency testing

Introduce user specified latency in the packet reception path
By exposing the test parameters as part of the debugfs channel
attributes. We will control

drivers: hv: vmbus: Introduce latency testing

Introduce user specified latency in the packet reception path
By exposing the test parameters as part of the debugfs channel
attributes. We will control the testing state via these attributes.

Signed-off-by: Branden Bonaby <brandonbonaby94@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Drivers: hv: vmbus: Resume after fixing up old primary channels

When the host re-offers the primary channels upon resume, the host only
guarantees the Instance GUID doesn't change, so vmbus_bus_sus

Drivers: hv: vmbus: Resume after fixing up old primary channels

When the host re-offers the primary channels upon resume, the host only
guarantees the Instance GUID doesn't change, so vmbus_bus_suspend()
should invalidate channel->offermsg.child_relid and figure out the
number of primary channels that need to be fixed up upon resume.

Upon resume, vmbus_onoffer() finds the old channel structs, and maps
the new offers to the old channels, and fixes up the old structs,
and finally the resume callbacks of the VSC drivers will re-open
the channels.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Drivers: hv: vmbus: Suspend after cleaning up hv_sock and sub channels

Before suspend, Linux must make sure all the hv_sock channels have been
properly cleaned up, because a hv_sock connection can n

Drivers: hv: vmbus: Suspend after cleaning up hv_sock and sub channels

Before suspend, Linux must make sure all the hv_sock channels have been
properly cleaned up, because a hv_sock connection can not persist across
hibernation, and the user-space app must be properly notified of the
state change of the connection.

Before suspend, Linux also must make sure all the sub-channels have been
destroyed, i.e. the related channel structs of the sub-channels must be
properly removed, otherwise they would cause a conflict when the
sub-channels are recreated upon resume.

Add a counter to track such channels, and vmbus_bus_suspend() should wait
for the counter to drop to zero.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation

Before Linux enters hibernation, it sends the CHANNELMSG_UNLOAD message to
the host so all the offers are gone. After hibernation,

Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation

Before Linux enters hibernation, it sends the CHANNELMSG_UNLOAD message to
the host so all the offers are gone. After hibernation, Linux needs to
re-negotiate with the host using the same vmbus protocol version (which
was in use before hibernation), and ask the host to re-offer the vmbus
devices.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Drivers: hv: vmbus: Break out synic enable and disable operations

Break out synic enable and disable operations into separate
hv_synic_disable_regs() and hv_synic_enable_regs() functions for use by

Drivers: hv: vmbus: Break out synic enable and disable operations

Break out synic enable and disable operations into separate
hv_synic_disable_regs() and hv_synic_enable_regs() functions for use by a
later patch to support hibernation.

There is no functional change except the unnecessary check
"if (sctrl.enable != 1) return -EFAULT;" which is removed, because when
we're in hv_synic_cleanup(), we're absolutely sure sctrl.enable must be 1.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...