Commit c41880b5 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Add helpers to get and modify a vCPU's CPUID entries 



Add helpers to get a specific CPUID entry for a given vCPU, and to toggle
a specific CPUID-based feature for a vCPU.  The helpers will reduce the
amount of boilerplate code needed to tweak a vCPU's CPUID model, improve
code clarity, and most importantly move tests away from modifying the
static "cpuid" returned by kvm_get_supported_cpuid().

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-23-seanjc@google.com
parent 662162fe

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

+30 −0
Original line number Diff line number Diff line
@@ -622,6 +622,19 @@ struct kvm_cpuid_entry2 *get_cpuid_entry(struct kvm_cpuid2 *cpuid, 
					 uint32_t function, uint32_t index);

void vcpu_init_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid);



static inline struct kvm_cpuid_entry2 *__vcpu_get_cpuid_entry(struct kvm_vcpu *vcpu,

							      uint32_t function,

							      uint32_t index)

{

	return get_cpuid_entry(vcpu->cpuid, function, index);

}



static inline struct kvm_cpuid_entry2 *vcpu_get_cpuid_entry(struct kvm_vcpu *vcpu,

							    uint32_t function)

{

	return __vcpu_get_cpuid_entry(vcpu, function, 0);

}



static inline int __vcpu_set_cpuid(struct kvm_vcpu *vcpu)

{

	int r;
@@ -645,6 +658,23 @@ static inline void vcpu_set_cpuid(struct kvm_vcpu *vcpu) 
	vcpu_ioctl(vcpu, KVM_GET_CPUID2, vcpu->cpuid);

}



void vcpu_set_or_clear_cpuid_feature(struct kvm_vcpu *vcpu,

				     struct kvm_x86_cpu_feature feature,

				     bool set);



static inline void vcpu_set_cpuid_feature(struct kvm_vcpu *vcpu,

					  struct kvm_x86_cpu_feature feature)

{

	vcpu_set_or_clear_cpuid_feature(vcpu, feature, true);



}



static inline void vcpu_clear_cpuid_feature(struct kvm_vcpu *vcpu,

					    struct kvm_x86_cpu_feature feature)

{

	vcpu_set_or_clear_cpuid_feature(vcpu, feature, false);

}



static inline struct kvm_cpuid_entry2 *kvm_get_supported_cpuid_index(uint32_t function,

								     uint32_t index)

{

tools/testing/selftests/kvm/lib/x86_64/processor.c

+18 −0
Original line number Diff line number Diff line
@@ -766,6 +766,24 @@ void vcpu_init_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid) 
	vcpu_set_cpuid(vcpu);

}



void vcpu_set_or_clear_cpuid_feature(struct kvm_vcpu *vcpu,

				     struct kvm_x86_cpu_feature feature,

				     bool set)

{

	struct kvm_cpuid_entry2 *entry;

	u32 *reg;



	entry = __vcpu_get_cpuid_entry(vcpu, feature.function, feature.index);

	reg = (&entry->eax) + feature.reg;



	if (set)

		*reg |= BIT(feature.bit);

	else

		*reg &= ~BIT(feature.bit);



	vcpu_set_cpuid(vcpu);

}



uint64_t vcpu_get_msr(struct kvm_vcpu *vcpu, uint64_t msr_index)

{

	struct {