nvmm: Fix comm page unmapping issue by doing it on userland side

Previously, we're mapping and unmapping the comm page for userland
process both on the kernel side. The unmapping was called at the

nvmm: Fix comm page unmapping issue by doing it on userland side

Previously, we're mapping and unmapping the comm page for userland
process both on the kernel side. The unmapping was called at the point
of closing the fd.

However, the kernel may destroy process' vmspace before or after closing
the fd, so there is no guarantee that kernel can get the correct address
space to unmap the comm page for the userland process. Therefore, do
the comm page unmapping on the userland side in libnvmm to fix the above
issue.

In addition, add the 'comm_size' member to 'struct nvmm_capability' to
expose the comm page size to userland, which is required for the
unmapping operation. This breaks ABI, so bump NVMM_KERN_VERSION.
Update nvmmctl(8) accordingly to print the comm page size.

This commit partially reverts:
"nvmm: Add missing comm page unmapping"

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nvmm: Move DragonFly module code in nvmm.c to nvmm_dragonfly.c

Move the OS-specific DragonFly module code in nvmm.c to nvmm_dragonfly.c,
making nvmm.c source file more OS-independent. Adjust severa

nvmm: Move DragonFly module code in nvmm.c to nvmm_dragonfly.c

Move the OS-specific DragonFly module code in nvmm.c to nvmm_dragonfly.c,
making nvmm.c source file more OS-independent. Adjust several static
functions and variables for this purpose.

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nvmm: Don't assume comm page size to be PAGE_SIZE

Don't assume the comm page size to be PAGE_SIZE but add the
'NVMM_COMM_PAGE_SIZE' macro to determine the size. So the code is
now independent to co

nvmm: Don't assume comm page size to be PAGE_SIZE

Don't assume the comm page size to be PAGE_SIZE but add the
'NVMM_COMM_PAGE_SIZE' macro to determine the size. So the code is
now independent to comm page size and thus it can be easily extended
in the future.

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nvmm: Add missing comm page unmapping

The comm page mapping has been changed from libnvmm to the kernel side,
so I removed the munmap() code from libnvmm, but the kernel wasn't doing
the unmapping.

nvmm: Add missing comm page unmapping

The comm page mapping has been changed from libnvmm to the kernel side,
so I removed the munmap() code from libnvmm, but the kernel wasn't doing
the unmapping. Now add the missing unmapping operation.

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nvmm - Change NVMM_MAX_RAM

* Add __NetBSD__ conditional back in with original 128GB limit.

* Set DragonFly limit to 127TB (down from 128TB) to ensure that
no valid memory exists at the canonical

nvmm - Change NVMM_MAX_RAM

* Add __NetBSD__ conditional back in with original 128GB limit.

* Set DragonFly limit to 127TB (down from 128TB) to ensure that
no valid memory exists at the canonical transition.

Additional limits may have to be set as Intel specifies that the
backing memory map not have an address space larger than the
hardware's physical address space.

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nvmm: More OS independence

* Abstract out various OS-specific defines and functions and organize
them in 'nvmm_os.h' and 'nvmm_os.c'. This provides more flexibility
for us to port NVMM to Drago

nvmm: More OS independence

* Abstract out various OS-specific defines and functions and organize
them in 'nvmm_os.h' and 'nvmm_os.c'. This provides more flexibility
for us to port NVMM to DragonFly and other OSes.
* Remove 'nvmm_compat.h' and merge the code into the above new files.

Some local changes specific to DragonFly are not abstracted out, and
there also exists some NetBSD-specific code. The current version only
builds and works on DragonFly.

The OS-dependent code in nvmm_os.* and nvmm_x86.h is a bit messy at the
moment. I'll further clean them up later.

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nvmm: Various misc cleanups and minor updates

* Rework header inclusions.
* Improve the arguments given to uvmspace_alloc().
* Lowercase "NVMM" in printf() logs.
* Reorganize a few macros in 'nvmm_x

nvmm: Various misc cleanups and minor updates

* Rework header inclusions.
* Improve the arguments given to uvmspace_alloc().
* Lowercase "NVMM" in printf() logs.
* Reorganize a few macros in 'nvmm_x86.h' for clarity.
* Remove NetBSD VCS markers and update copyright.

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nvmm: Reduce NVMM_MAX_VCPUS from 256 to 128

Unfortunately not all x86 guests can work with a max value of 256, due
to overflowing uint8_t. Reduce it to 128.

nvmm: Rename a few things for clarity

nvmm - Change max emulated RAM from 128GB to 128TB

* Increase the max emulated RAM from 128GB to 128TB. Ok, I'm not
sure what the actual maximum is, but it sure as heck is more
than 128GB.

* S

nvmm - Change max emulated RAM from 128GB to 128TB

* Increase the max emulated RAM from 128GB to 128TB. Ok, I'm not
sure what the actual maximum is, but it sure as heck is more
than 128GB.

* Successfully booted a 8TB qemu on the threadripper (host ate
~275GB to boot it, mostly initializing the vm_page_array[]).

This points to other things we could work on in the kernel
to reduce memory overhead. Our really fat struct vm_page's,
for one.

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nvmm: Improve nvmm_return_needed() by using nvmm_break_wanted()

Use the newly added nvmm_break_wanted() routine to check for pending
host events, improving nvmm_return_needed(). Just stuff
nvmm_bre

nvmm: Improve nvmm_return_needed() by using nvmm_break_wanted()

Use the newly added nvmm_break_wanted() routine to check for pending
host events, improving nvmm_return_needed(). Just stuff
nvmm_break_wanted() into nvmm_return_needed() and get rid of
preempt_needed(), making the code clearer.

Also add __predict_false() macro to help performance a bit.

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NVMM: Sync with NetBSD #1: copyright headers

nvmm: Rewrite makefiles and hook to build

Note that kernel header files are install by the top-level
'include/Makefile'. However, it will install all found header
files in the specified directories

nvmm: Rewrite makefiles and hook to build

Note that kernel header files are install by the top-level
'include/Makefile'. However, it will install all found header
files in the specified directories, including 'nvmm_compat.h'
and 'nvmm_internal.h'. Therefore, add a guard to prevent them
from including by userland utilities (e.g., libnvmm, nvmmctl).

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nvmm: Port to DragonFly #20: preemption & critical section

In DragonFly, a normal kernel thread will not migrate to another CPU or be
preempted (except by an interrupt thread), so kpreempt_{disable,

nvmm: Port to DragonFly #20: preemption & critical section

In DragonFly, a normal kernel thread will not migrate to another CPU or be
preempted (except by an interrupt thread), so kpreempt_{disable,enable}()
are not needed. However, we can't use critical section as an instead,
because that would also prevent interrupt/reschedule flags from being
set, which would be a problem for nvmm_return_needed() that's called from
vcpu_run() loop. (credit to Matt Dillon)

Port nvmm_return_needed() to DragonFly. But note that the
*_resched_wanted() functions cannot be used in critical sections, which
would prevent the relevant flags from being set. (credit to Matt Dillon)

Port splhigh()/splx() as critical sections in DragonFly for the moment.
Don't worry about it unless we have issues with it later.

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nvmm: Bring some minor changes from NetBSD-current

These changes help port NVMM to DragonFly by reducing the required
difference.

Import nvmm(4) from NetBSD 9-stable

This is the kernel driver that provides support for hardware-accelerated
virtualization. It is made of an MI frontend with the following two MD
backends:
- x86 I

Import nvmm(4) from NetBSD 9-stable

This is the kernel driver that provides support for hardware-accelerated
virtualization. It is made of an MI frontend with the following two MD
backends:
- x86 Intel VMX
- x86 AMD SVM

Branch: NetBSD 9-stable
Date: Fri Apr 30 14:08:16 2021 +0000
Path: sys/dev/nvmm

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