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charset="UTF-8" Adjust the EFER.LMSLE testcases to expect failure, not success, when attempting to stuff EFER.LMSLE=1 even when the guest CPUID model is configured with EFER_LMSLE_MBZ enabled, i.e. when it should be impossible to set EFER.LMSLE=1. KVM's ABI is that userspace *must* set CPUID and feature MSRs before restoring (or stuffing) vCPU state, i.e. before writing normal MSRs. The previous KVM behavior of allowing usersepace to stuff garbage was a KVM bug (that has since been fixed). Reported-by: Sashiko Bot Closes: https://lore.kernel.org/all/sashiko-outbox-182135@kernel.org Signed-off-by: Sean Christopherson --- .../selftests/kvm/x86/svm_nested_efer_test.c | 20 ++++++------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/tools/testing/selftests/kvm/x86/svm_nested_efer_test.c b/tools/testing/selftests/kvm/x86/svm_nested_efer_test.c index fa9cfe8b1242..bdec7cdb3714 100644 --- a/tools/testing/selftests/kvm/x86/svm_nested_efer_test.c +++ b/tools/testing/selftests/kvm/x86/svm_nested_efer_test.c @@ -193,23 +193,20 @@ static void test_host_initiated_lmsle(void) struct kvm_vcpu *vcpu; struct kvm_vm *vm; u64 efer; + int r; vm = vm_create_with_one_vcpu(&vcpu, NULL); vcpu_set_cpuid_feature(vcpu, X86_FEATURE_EFER_LMSLE_MBZ); - /* - * EFER_LMSLE_MBZ is a guest CPUID consistency check, not a host - * capability, i.e. must not be enforced against host-initiated writes, - * so that userspace can set MSRs before it sets guest CPUID. - */ efer = vcpu_get_msr(vcpu, MSR_EFER); TEST_ASSERT(!(efer & EFER_LMSLE), "EFER.LMSLE unexpectedly set"); - vcpu_set_msr(vcpu, MSR_EFER, efer | EFER_LMSLE); - TEST_ASSERT_EQ(vcpu_get_msr(vcpu, MSR_EFER), efer | EFER_LMSLE); + r = _vcpu_set_msr(vcpu, MSR_EFER, efer | EFER_LMSLE); + TEST_ASSERT_EQ(r, 0); + TEST_ASSERT_EQ(vcpu_get_msr(vcpu, MSR_EFER), efer); kvm_vm_free(vm); - ksft_test_result_pass("Host-initiated EFER.LMSLE=1 is allowed\n"); + ksft_test_result_pass("KVM_SET_MSRS rejects EFER.LMSLE=1 with EFER_LMSLE_MBZ\n"); } static void test_sregs_lmsle(void) @@ -222,11 +219,6 @@ static void test_sregs_lmsle(void) vm = vm_create_with_one_vcpu(&vcpu, NULL); vcpu_set_cpuid_feature(vcpu, X86_FEATURE_EFER_LMSLE_MBZ); - /* - * Unlike KVM_SET_MSRS, KVM_SET_SREGS runs the full set of guest CPUID - * checks, i.e. rejects EFER.LMSLE even though it's host-initiated. - */ - vcpu_sregs_get(vcpu, &sregs); TEST_ASSERT(!(sregs.efer & EFER_LMSLE), "EFER.LMSLE unexpectedly set"); sregs.efer |= EFER_LMSLE; @@ -275,7 +267,7 @@ int main(int argc, char *argv[]) test_sregs_lmsle(); } else { ksft_test_result_skip("Guest EFER_LMSLE_MBZ=0\n"); - ksft_test_result_skip("Host-initiated EFER.LMSLE=1 is allowed\n"); + ksft_test_result_skip("KVM_SET_MSRS rejects EFER.LMSLE=1 with EFER_LMSLE_MBZ\n"); ksft_test_result_skip("KVM_SET_SREGS rejects EFER.LMSLE=1\n"); } -- 2.56.0.307.g5fe7bd680c-goog