Commit 48ce3ed0 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

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: default avatarSean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-33-seanjc@google.com
parent 8fe09d6a

tools/testing/selftests/kvm/include/x86_64/processor.h

+11 −1
Original line number Diff line number Diff line
@@ -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)

tools/testing/selftests/kvm/x86_64/amx_test.c

+2 −7
Original line number Diff line number Diff line
@@ -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)