Re: [PATCH 11/11] KVM: selftests: Ensure KVM supports AVX for SEV-ES VMSA FPU test
From: Vitaly Kuznetsov
Date: Fri Oct 04 2024 - 05:15:10 EST
Sean Christopherson <seanjc@xxxxxxxxxx> writes:
> Verify that KVM's supported XCR0 includes AVX (and earlier features) when
> running the SEV-ES VMSA XSAVE test. In practice, the issue will likely
> never pop up, since KVM support for AVX predates KVM support for SEV-ES,
> but checking for KVM support makes the requirement more obvious.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/x86_64/sev_smoke_test.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c b/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
> index 965fc362dee3..ae77698e6e97 100644
> --- a/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
> @@ -181,6 +181,8 @@ static void test_sev_es_shutdown(void)
>
> int main(int argc, char *argv[])
> {
> + const u64 xf_mask = XFEATURE_MASK_X87_AVX;
> +
> TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SEV));
>
> test_sev(guest_sev_code, SEV_POLICY_NO_DBG);
> @@ -193,7 +195,7 @@ int main(int argc, char *argv[])
> test_sev_es_shutdown();
>
> if (kvm_has_cap(KVM_CAP_XCRS) &&
> - (xgetbv(0) & XFEATURE_MASK_X87_AVX) == XFEATURE_MASK_X87_AVX) {
> + (xgetbv(0) & kvm_cpu_supported_xcr0() & xf_mask) == xf_mask) {
> test_sync_vmsa(0);
> test_sync_vmsa(SEV_POLICY_NO_DBG);
> }
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
--
Vitaly