Use KVM or HVF if supported by the QEMU binary and available on the
system.
This produces a nice improvement on my Apple M3 Pro running macOS 14.7:
Before:
./tools/testing/kunit/kunit.py exec --arch arm64
[HH:MM:SS] Elapsed time: 10.145s
After:
./tools/testing/kunit/kunit.py exec --arch arm64
[HH:MM:SS] Elapsed time: 1.773s
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
---
tools/testing/kunit/kunit_kernel.py | 26 +++++++++++++++++++++++++-
tools/testing/kunit/qemu_configs/arm64.py | 2 +-
2 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
index 61931c4926fd6645f2c62dd13f9842a432ec4167..10cacf5a3c443bacd6c074647e4bddfc31599cf8 100644
--- a/tools/testing/kunit/kunit_kernel.py
+++ b/tools/testing/kunit/kunit_kernel.py
@@ -116,7 +116,8 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
kernel_path = os.path.join(build_dir, self._kernel_path)
- qemu_command = ['qemu-system-' + self._qemu_arch,
+ qemu_binary = 'qemu-system-' + self._qemu_arch
+ qemu_command = [qemu_binary,
'-nodefaults',
'-m', '1024',
'-kernel', kernel_path,
@@ -124,6 +125,29 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
'-no-reboot',
'-nographic',
'-serial', self._serial] + self._extra_qemu_params
+ accelerators = {
+ line.strip()
+ for line in subprocess.check_output([qemu_binary, "-accel", "help"], text=True).splitlines()
+ if line and line.islower()
+ }
+ if 'kvm' in accelerators:
+ try:
+ with open('/dev/kvm', 'rb+'):
+ qemu_command.extend(['-accel', 'kvm'])
+ except OSError as e:
+ print(e)
+ elif 'hvf' in accelerators:
+ try:
+ for line in subprocess.check_output(['sysctl', 'kern.hv_support'], text=True).splitlines():
+ if not line:
+ continue
+ key, value = line.split(':')
+ if key == 'kern.hv_support' and bool(value):
+ qemu_command.extend(['-accel', 'hvf'])
+ break
+ except subprocess.CalledProcessError as e:
+ print(e)
+
# Note: shlex.join() does what we want, but requires python 3.8+.
print('Running tests with:\n$', ' '.join(shlex.quote(arg) for arg in qemu_command))
return subprocess.Popen(qemu_command,
diff --git a/tools/testing/kunit/qemu_configs/arm64.py b/tools/testing/kunit/qemu_configs/arm64.py
index d3ff27024755411441f910799be30399295c9541..5c44d3a87e6dd2cd6b086138186a277a1473585b 100644
--- a/tools/testing/kunit/qemu_configs/arm64.py
+++ b/tools/testing/kunit/qemu_configs/arm64.py
@@ -9,4 +9,4 @@ CONFIG_SERIAL_AMBA_PL011_CONSOLE=y''',
qemu_arch='aarch64',
kernel_path='arch/arm64/boot/Image.gz',
kernel_command_line='console=ttyAMA0',
- extra_qemu_params=['-machine', 'virt', '-cpu', 'max,pauth-impdef=on'])
+ extra_qemu_params=['-machine', 'virt', '-cpu', 'max'])
--
2.47.0On Fri, Oct 25, 2024 at 05:03:54PM -0400, Tamir Duberstein wrote:
> @@ -124,6 +125,29 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
> '-no-reboot',
> '-nographic',
> '-serial', self._serial] + self._extra_qemu_params
> + accelerators = {
> + line.strip()
> + for line in subprocess.check_output([qemu_binary, "-accel", "help"], text=True).splitlines()
> + if line and line.islower()
> + }
> + if 'kvm' in accelerators:
> + try:
> + with open('/dev/kvm', 'rb+'):
> + qemu_command.extend(['-accel', 'kvm'])
> + except OSError as e:
> + print(e)
> + elif 'hvf' in accelerators:
> + try:
> + for line in subprocess.check_output(['sysctl', 'kern.hv_support'], text=True).splitlines():
> + if not line:
> + continue
> + key, value = line.split(':')
> + if key == 'kern.hv_support' and bool(value):
> + qemu_command.extend(['-accel', 'hvf'])
> + break
> + except subprocess.CalledProcessError as e:
> + print(e)
> +
QEMU supports falling back if one accelerator is not available, if you
specify multiple like -accel kvm:tcg. Couldn't you rely on that rather
than re-implementing the availability checks here?
On Fri, Nov 1, 2024, 09:52 Alyssa Ross <hi@alyssa.is> wrote:
>
> On Fri, Oct 25, 2024 at 05:03:54PM -0400, Tamir Duberstein wrote:
> > @@ -124,6 +125,29 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
> > '-no-reboot',
> > '-nographic',
> > '-serial', self._serial] + self._extra_qemu_params
> > + accelerators = {
> > + line.strip()
> > + for line in subprocess.check_output([qemu_binary, "-accel", "help"], text=True).splitlines()
> > + if line and line.islower()
> > + }
> > + if 'kvm' in accelerators:
> > + try:
> > + with open('/dev/kvm', 'rb+'):
> > + qemu_command.extend(['-accel', 'kvm'])
> > + except OSError as e:
> > + print(e)
> > + elif 'hvf' in accelerators:
> > + try:
> > + for line in subprocess.check_output(['sysctl', 'kern.hv_support'], text=True).splitlines():
> > + if not line:
> > + continue
> > + key, value = line.split(':')
> > + if key == 'kern.hv_support' and bool(value):
> > + qemu_command.extend(['-accel', 'hvf'])
> > + break
> > + except subprocess.CalledProcessError as e:
> > + print(e)
> > +
>
> QEMU supports falling back if one accelerator is not available, if you
> specify multiple like -accel kvm:tcg. Couldn't you rely on that rather
> than re-implementing the availability checks here?
Have you ever used that? Here's what I get when I try:
tamird@Tamirs-MacBook-Pro linux % tools/testing/kunit/kunit.py run
--arch arm64 --make_options LLVM=1 --raw_output=all
[10:45:03] Configuring KUnit Kernel ...
[10:45:03] Building KUnit Kernel ...
Populating config with:
$ make ARCH=arm64 O=.kunit olddefconfig LLVM=1
Building with:
$ make all compile_commands.json ARCH=arm64 O=.kunit --jobs=12 LLVM=1
[10:45:07] Starting KUnit Kernel (1/1)...
Running tests with:
$ qemu-system-aarch64 -nodefaults -m 1024 -kernel
.kunit/arch/arm64/boot/Image.gz -append 'kunit.enable=1
console=ttyAMA0 kunit_shutdown=reboot' -no-reboot -nographic -serial
stdio -accel kvm:tcg -machine virt -cpu max
qemu-system-aarch64: -accel kvm:tcg: invalid accelerator kvm:tcg
The same thing happens with hvf:kvm:tcg or just hvf:tcg.
I also can't find this in the documentation.
Tamir
On 2024-11-01 10:49:36-0400, Tamir Duberstein wrote:
> On Fri, Nov 1, 2024, 09:52 Alyssa Ross <hi@alyssa.is> wrote:
> >
> > On Fri, Oct 25, 2024 at 05:03:54PM -0400, Tamir Duberstein wrote:
> > > @@ -124,6 +125,29 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
> > > '-no-reboot',
> > > '-nographic',
> > > '-serial', self._serial] + self._extra_qemu_params
> > > + accelerators = {
> > > + line.strip()
> > > + for line in subprocess.check_output([qemu_binary, "-accel", "help"], text=True).splitlines()
> > > + if line and line.islower()
> > > + }
> > > + if 'kvm' in accelerators:
> > > + try:
> > > + with open('/dev/kvm', 'rb+'):
> > > + qemu_command.extend(['-accel', 'kvm'])
> > > + except OSError as e:
> > > + print(e)
> > > + elif 'hvf' in accelerators:
> > > + try:
> > > + for line in subprocess.check_output(['sysctl', 'kern.hv_support'], text=True).splitlines():
> > > + if not line:
> > > + continue
> > > + key, value = line.split(':')
> > > + if key == 'kern.hv_support' and bool(value):
> > > + qemu_command.extend(['-accel', 'hvf'])
> > > + break
> > > + except subprocess.CalledProcessError as e:
> > > + print(e)
> > > +
> >
> > QEMU supports falling back if one accelerator is not available, if you
> > specify multiple like -accel kvm:tcg. Couldn't you rely on that rather
> > than re-implementing the availability checks here?
>
> Have you ever used that? Here's what I get when I try:
>
> tamird@Tamirs-MacBook-Pro linux % tools/testing/kunit/kunit.py run
> --arch arm64 --make_options LLVM=1 --raw_output=all
> [10:45:03] Configuring KUnit Kernel ...
> [10:45:03] Building KUnit Kernel ...
> Populating config with:
> $ make ARCH=arm64 O=.kunit olddefconfig LLVM=1
> Building with:
> $ make all compile_commands.json ARCH=arm64 O=.kunit --jobs=12 LLVM=1
> [10:45:07] Starting KUnit Kernel (1/1)...
> Running tests with:
> $ qemu-system-aarch64 -nodefaults -m 1024 -kernel
> .kunit/arch/arm64/boot/Image.gz -append 'kunit.enable=1
> console=ttyAMA0 kunit_shutdown=reboot' -no-reboot -nographic -serial
> stdio -accel kvm:tcg -machine virt -cpu max
> qemu-system-aarch64: -accel kvm:tcg: invalid accelerator kvm:tcg
>
> The same thing happens with hvf:kvm:tcg or just hvf:tcg.
That syntax is for -machine accel=hvf:kvm:tcg.
But you can also specify -accel multiple times.
> I also can't find this in the documentation.
-accel name[,prop=value[,...]]
This is used to enable an accelerator. [..]
If there is more than one accelerator specified,
the next one is used if the previous one fails to initialize.
-machine [type=]name[,prop=value[,...]]
Supported machine properties are:
accel=accels1[:accels2[:...]]
[..]
If there is more than one accelerator specified,
the next one is used if the previous one fails to initialize.
Thomas
On Fri, Nov 1, 2024 at 11:23 AM Thomas Weißschuh <thomas@t-8ch.de> wrote:
>
> On 2024-11-01 10:49:36-0400, Tamir Duberstein wrote:
> > On Fri, Nov 1, 2024, 09:52 Alyssa Ross <hi@alyssa.is> wrote:
> > >
> > > On Fri, Oct 25, 2024 at 05:03:54PM -0400, Tamir Duberstein wrote:
> > > > @@ -124,6 +125,29 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
> > > > '-no-reboot',
> > > > '-nographic',
> > > > '-serial', self._serial] + self._extra_qemu_params
> > > > + accelerators = {
> > > > + line.strip()
> > > > + for line in subprocess.check_output([qemu_binary, "-accel", "help"], text=True).splitlines()
> > > > + if line and line.islower()
> > > > + }
> > > > + if 'kvm' in accelerators:
> > > > + try:
> > > > + with open('/dev/kvm', 'rb+'):
> > > > + qemu_command.extend(['-accel', 'kvm'])
> > > > + except OSError as e:
> > > > + print(e)
> > > > + elif 'hvf' in accelerators:
> > > > + try:
> > > > + for line in subprocess.check_output(['sysctl', 'kern.hv_support'], text=True).splitlines():
> > > > + if not line:
> > > > + continue
> > > > + key, value = line.split(':')
> > > > + if key == 'kern.hv_support' and bool(value):
> > > > + qemu_command.extend(['-accel', 'hvf'])
> > > > + break
> > > > + except subprocess.CalledProcessError as e:
> > > > + print(e)
> > > > +
> > >
> > > QEMU supports falling back if one accelerator is not available, if you
> > > specify multiple like -accel kvm:tcg. Couldn't you rely on that rather
> > > than re-implementing the availability checks here?
> >
> > Have you ever used that? Here's what I get when I try:
> >
> > tamird@Tamirs-MacBook-Pro linux % tools/testing/kunit/kunit.py run
> > --arch arm64 --make_options LLVM=1 --raw_output=all
> > [10:45:03] Configuring KUnit Kernel ...
> > [10:45:03] Building KUnit Kernel ...
> > Populating config with:
> > $ make ARCH=arm64 O=.kunit olddefconfig LLVM=1
> > Building with:
> > $ make all compile_commands.json ARCH=arm64 O=.kunit --jobs=12 LLVM=1
> > [10:45:07] Starting KUnit Kernel (1/1)...
> > Running tests with:
> > $ qemu-system-aarch64 -nodefaults -m 1024 -kernel
> > .kunit/arch/arm64/boot/Image.gz -append 'kunit.enable=1
> > console=ttyAMA0 kunit_shutdown=reboot' -no-reboot -nographic -serial
> > stdio -accel kvm:tcg -machine virt -cpu max
> > qemu-system-aarch64: -accel kvm:tcg: invalid accelerator kvm:tcg
> >
> > The same thing happens with hvf:kvm:tcg or just hvf:tcg.
>
> That syntax is for -machine accel=hvf:kvm:tcg.
> But you can also specify -accel multiple times.
>
> > I also can't find this in the documentation.
>
> -accel name[,prop=value[,...]]
> This is used to enable an accelerator. [..]
> If there is more than one accelerator specified,
> the next one is used if the previous one fails to initialize.
>
> -machine [type=]name[,prop=value[,...]]
> Supported machine properties are:
>
> accel=accels1[:accels2[:...]]
> [..]
> If there is more than one accelerator specified,
> the next one is used if the previous one fails to initialize.
>
>
> Thomas
Nice, thank you. These details seem to appear only in the docs[0] and
not in the output of `--help`. I'll make that change in v2.
Link: https://www.qemu.org/docs/master/system/invocation.html [0]
Tamir
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