The msr_filter_deny test covers the FILTER and UNKNOWN MSR exit reasons, but nothing exercises KVM_MSR_EXIT_REASON_INVAL.
Have the guest set a reserved bit (bit 63) in EFER while preserving the other bits, and verify that the write exits to userspace with KVM_MSR_EXIT_REASON_INVAL along with the attempted value. Signed-off-by: Tharit Tangkijwanichakul <[email protected]> --- Tested on Intel Core i5-10210U (VMX). Not tested on AMD. --- .../selftests/kvm/x86/userspace_msr_exit_test.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/x86/userspace_msr_exit_test.c b/tools/testing/selftests/kvm/x86/userspace_msr_exit_test.c index 2808ce727e5f..7446e1404264 100644 --- a/tools/testing/selftests/kvm/x86/userspace_msr_exit_test.c +++ b/tools/testing/selftests/kvm/x86/userspace_msr_exit_test.c @@ -309,6 +309,9 @@ static void guest_msr_calls(bool trapped) /* Invalid MSR, should always be handled by user space exit */ GUEST_ASSERT(rdmsr(0xdeadbeef) == 0xdeadbeef); wrmsr(0xdeadbeef, 0x1234); + + /* Setting a reserved EFER bit is rejected by KVM, exit with INVAL */ + wrmsr(MSR_EFER, rdmsr(MSR_EFER) | BIT_ULL(63)); } static void guest_code_filter_deny(void) @@ -627,6 +630,13 @@ static void handle_wrmsr(struct kvm_run *run) TEST_ASSERT(run->msr.reason == KVM_MSR_EXIT_REASON_UNKNOWN, "deadbeef trap w/o inval fault"); } + + if (run->msr.index == MSR_EFER) { + TEST_ASSERT(run->msr.data & BIT_ULL(63), + "MSR_EFER data missing reserved bit"); + TEST_ASSERT(run->msr.reason == KVM_MSR_EXIT_REASON_INVAL, + "MSR_EFER trap w/o inval fault"); + } } KVM_ONE_VCPU_TEST(user_msr, msr_filter_deny, guest_code_filter_deny) @@ -667,7 +677,7 @@ KVM_ONE_VCPU_TEST(user_msr, msr_filter_deny, guest_code_filter_deny) done: TEST_ASSERT(msr_reads == 4, "Handled 4 rdmsr in user space"); - TEST_ASSERT(msr_writes == 3, "Handled 3 wrmsr in user space"); + TEST_ASSERT(msr_writes == 5, "Handled 5 wrmsr in user space"); } KVM_ONE_VCPU_TEST(user_msr, msr_permission_bitmap, guest_code_permission_bitmap) -- 2.53.0
