From 48ce3ed052e8336a17c64ca1787648d9e17c54d9 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 14 Jun 2022 20:06:57 +0000 Subject: KVM: selftests: Add this_cpu_has() to query X86_FEATURE_* via cpuid() Add this_cpu_has() to query an X86_FEATURE_* via cpuid(), i.e. to query a feature from L1 (or L2) guest code. Arbitrarily select the AMX test to be the first user. Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20220614200707.3315957-33-seanjc@google.com --- tools/testing/selftests/kvm/include/x86_64/processor.h | 12 +++++++++++- tools/testing/selftests/kvm/x86_64/amx_test.c | 9 ++------- 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 47e74beda155..b065d6cadba1 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -161,7 +161,6 @@ struct kvm_x86_cpu_feature { #define X86_FEATURE_KVM_MIGRATION_CONTROL KVM_X86_CPU_FEATURE(0x40000001, 0, EAX, 17) /* CPUID.1.ECX */ -#define CPUID_XSAVE (1ul << 26) #define CPUID_OSXSAVE (1ul << 27) /* Page table bitfield declarations */ @@ -427,6 +426,17 @@ static inline void cpuid(uint32_t function, return __cpuid(function, 0, eax, ebx, ecx, edx); } +static inline bool this_cpu_has(struct kvm_x86_cpu_feature feature) +{ + uint32_t gprs[4]; + + __cpuid(feature.function, feature.index, + &gprs[KVM_CPUID_EAX], &gprs[KVM_CPUID_EBX], + &gprs[KVM_CPUID_ECX], &gprs[KVM_CPUID_EDX]); + + return gprs[feature.reg] & BIT(feature.bit); +} + #define SET_XMM(__var, __xmm) \ asm volatile("movq %0, %%"#__xmm : : "r"(__var) : #__xmm) diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c index cb5e20936cc1..c867f10532af 100644 --- a/tools/testing/selftests/kvm/x86_64/amx_test.c +++ b/tools/testing/selftests/kvm/x86_64/amx_test.c @@ -120,13 +120,8 @@ static inline void __xsavec(struct xsave_data *data, uint64_t rfbm) static inline void check_cpuid_xsave(void) { - uint32_t eax, ebx, ecx, edx; - - cpuid(1, &eax, &ebx, &ecx, &edx); - if (!(ecx & CPUID_XSAVE)) - GUEST_ASSERT(!"cpuid: no CPU xsave support!"); - if (!(ecx & CPUID_OSXSAVE)) - GUEST_ASSERT(!"cpuid: no OS xsave support!"); + GUEST_ASSERT(this_cpu_has(X86_FEATURE_XSAVE)); + GUEST_ASSERT(this_cpu_has(X86_FEATURE_OSXSAVE)); } static bool check_xsave_supports_xtile(void) -- cgit v1.2.3-59-g8ed1b