Commit 2c761313 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Extend cpuid_test to verify KVM_GET_CPUID2 "nent" updates 

Verify that KVM reports the actual number of CPUID entries on success, but
doesn't touch the userspace struct on failure (which for better or worse,
is KVM's ABI).

Link: https://lore.kernel.org/r/20230526210340.2799158-3-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent ab322c43

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

+21 −0
Original line number Diff line number Diff line
@@ -163,6 +163,25 @@ static void set_cpuid_after_run(struct kvm_vcpu *vcpu) 
	ent->eax = eax;

}



static void test_get_cpuid2(struct kvm_vcpu *vcpu)

{

	struct kvm_cpuid2 *cpuid = allocate_kvm_cpuid2(vcpu->cpuid->nent + 1);

	int i, r;



	vcpu_ioctl(vcpu, KVM_GET_CPUID2, cpuid);

	TEST_ASSERT(cpuid->nent == vcpu->cpuid->nent,

		    "KVM didn't update nent on success, wanted %u, got %u\n",

		    vcpu->cpuid->nent, cpuid->nent);



	for (i = 0; i < vcpu->cpuid->nent; i++) {

		cpuid->nent = i;

		r = __vcpu_ioctl(vcpu, KVM_GET_CPUID2, cpuid);

		TEST_ASSERT(r && errno == E2BIG, KVM_IOCTL_ERROR(KVM_GET_CPUID2, r));

		TEST_ASSERT(cpuid->nent == i, "KVM modified nent on failure");

	}

	free(cpuid);

}



int main(void)

{

	struct kvm_vcpu *vcpu;
@@ -183,5 +202,7 @@ int main(void) 


	set_cpuid_after_run(vcpu);



	test_get_cpuid2(vcpu);



	kvm_vm_free(vm);

}