From 2c76131319982f9c9410bc12127ac1df4e810b87 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 26 May 2023 14:03:40 -0700 Subject: [PATCH] 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: Sean Christopherson --- tools/testing/selftests/kvm/x86_64/cpuid_test.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/tools/testing/selftests/kvm/x86_64/cpuid_test.c b/tools/testing/selftests/kvm/x86_64/cpuid_test.c index 2fc3ad9..d3c3aa9 100644 --- a/tools/testing/selftests/kvm/x86_64/cpuid_test.c +++ b/tools/testing/selftests/kvm/x86_64/cpuid_test.c @@ -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); } -- 2.7.4