Re: [PATCH v2 1/2] KVM: selftests: Assert that XSAVE supports XTILE in amx_test

Sean Christopherson
2023-01-03T18:14:07Z

On Fri, Dec 30, 2022, Aaron Lewis wrote:
> The check in amx_test that ensures that XSAVE supports XTILE, doesn't
> actually check anything. It simply returns a bool which the test does
> nothing with.
>
> Assert that XSAVE supports XTILE.
>
> Fixes: 5dc19f1c7dd3 ("KVM: selftests: Convert AMX test to use X86_PROPRETY_XXX")

Doh.

> Signed-off-by: Aaron Lewis <aaronlewis@google.com>
> ---
> tools/testing/selftests/kvm/x86_64/amx_test.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c
> index bd72c6eb3b670..2f555f5c93e99 100644
> --- a/tools/testing/selftests/kvm/x86_64/amx_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/amx_test.c
> @@ -119,9 +119,9 @@ static inline void check_cpuid_xsave(void)
> GUEST_ASSERT(this_cpu_has(X86_FEATURE_OSXSAVE));
> }
>
> -static bool check_xsave_supports_xtile(void)
> +static inline void check_xsave_supports_xtile(void)

Don't explicitly tag local static functions as inline (ignore the existing code
that sets a bad precedent), modern compilers don't need the hint to generate
optimal code,

> {
> - return __xgetbv(0) & XFEATURE_MASK_XTILE;
> + GUEST_ASSERT(__xgetbv(0) & XFEATURE_MASK_XTILE);

Any objection to moving the assertion into check_xtile_info() and dropping this
one-line helper?

> }
>
> static void check_xtile_info(void)
> --
> 2.39.0.314.g84b9a713c41-goog
>