Re: [kvm-unit-tests PATCH v3] runtime: Allow to specify properties for accelerator

[Andrew Jones <andrew.jones@linux.dev>]

On Thu, Jun 15, 2023 at 04:21:48PM +1000, Gavin Shan wrote:
> There are extra properties for accelerators to enable the specific
> features. For example, the dirty ring for KVM accelerator can be
> enabled by "-accel kvm,dirty-ring-size=65536". Unfortuntely, the
> extra properties for the accelerators aren't supported. It makes
> it's impossible to test the combination of KVM and dirty ring
> as the following error message indicates.
> 
>   # cd /home/gavin/sandbox/kvm-unit-tests/tests
>   # QEMU=/home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \
>     ACCEL=kvm,dirty-ring-size=65536 ./its-migration
>      :
>   BUILD_HEAD=2fffb37e
>   timeout -k 1s --foreground 90s /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \
>   -nodefaults -machine virt -accel kvm,dirty-ring-size=65536 -cpu cortex-a57             \
>   -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd   \
>   -device pci-testdev -display none -serial stdio -kernel _NO_FILE_4Uhere_ -smp 160      \
>   -machine gic-version=3 -append its-pending-migration # -initrd /tmp/tmp.gfDLa1EtWk
>   qemu-system-aarch64: kvm_init_vcpu: kvm_arch_init_vcpu failed (0): Invalid argument
> 
> Allow to specify extra properties for accelerators. With this, the
> "its-migration" can be tested for the combination of KVM and dirty
> ring.
> 
> Signed-off-by: Gavin Shan <gshan@redhat.com>
> ---
> v3: Split $ACCEL to $ACCEL and $ACCEL_PROPS in get_qemu_accelerator()
>     and don't print them as output, suggested by Drew.
> ---
>  arm/run               | 12 ++++--------
>  powerpc/run           |  5 ++---
>  s390x/run             |  5 ++---
>  scripts/arch-run.bash | 21 +++++++++++++--------
>  x86/run               |  5 ++---
>  5 files changed, 23 insertions(+), 25 deletions(-)
> 
> diff --git a/arm/run b/arm/run
> index c6f25b8..d9ebe59 100755
> --- a/arm/run
> +++ b/arm/run
> @@ -10,10 +10,8 @@ if [ -z "$KUT_STANDALONE" ]; then
>  fi
>  processor="$PROCESSOR"
>  
> -accel=$(get_qemu_accelerator) ||
> -	exit $?
> -
> -if [ "$accel" = "kvm" ]; then
> +get_qemu_accelerator || exit $?
> +if [ "$ACCEL" = "kvm" ]; then
>  	QEMU_ARCH=$HOST
>  fi
>  
> @@ -23,11 +21,9 @@ qemu=$(search_qemu_binary) ||
>  if [ "$QEMU" ] && [ -z "$ACCEL" ] &&
>     [ "$HOST" = "aarch64" ] && [ "$ARCH" = "arm" ] &&
>     [ "$(basename $QEMU)" = "qemu-system-arm" ]; then
> -	accel=tcg
> +	ACCEL="tcg"
>  fi
>  

As I pointed out in the v2 review we can't just s/accel/ACCEL/ without
other changes. Now ACCEL will also be set when the above condition
is checked, making it useless. Please ensure the test case that commit
c7d6c7f00e7c ("arm/run: Use TCG with qemu-system-arm on arm64 systems")
fixed still works with your patch.

Thanks,
drew