diff options
Diffstat (limited to 'tools/testing/selftests/kvm/x86_64/xss_msr_test.c')
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/xss_msr_test.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/xss_msr_test.c b/tools/testing/selftests/kvm/x86_64/xss_msr_test.c new file mode 100644 index 0000000000..e0ddf47362 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/xss_msr_test.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019, Google LLC. + * + * Tests for the IA32_XSS MSR. + */ + +#define _GNU_SOURCE /* for program_invocation_short_name */ +#include <sys/ioctl.h> + +#include "test_util.h" +#include "kvm_util.h" +#include "vmx.h" + +#define MSR_BITS 64 + +int main(int argc, char *argv[]) +{ + bool xss_in_msr_list; + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + uint64_t xss_val; + int i, r; + + /* Create VM */ + vm = vm_create_with_one_vcpu(&vcpu, NULL); + + TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVES)); + + xss_val = vcpu_get_msr(vcpu, MSR_IA32_XSS); + TEST_ASSERT(xss_val == 0, + "MSR_IA32_XSS should be initialized to zero\n"); + + vcpu_set_msr(vcpu, MSR_IA32_XSS, xss_val); + + /* + * At present, KVM only supports a guest IA32_XSS value of 0. Verify + * that trying to set the guest IA32_XSS to an unsupported value fails. + * Also, in the future when a non-zero value succeeds check that + * IA32_XSS is in the list of MSRs to save/restore. + */ + xss_in_msr_list = kvm_msr_is_in_save_restore_list(MSR_IA32_XSS); + for (i = 0; i < MSR_BITS; ++i) { + r = _vcpu_set_msr(vcpu, MSR_IA32_XSS, 1ull << i); + + /* + * Setting a list of MSRs returns the entry that "faulted", or + * the last entry +1 if all MSRs were successfully written. + */ + TEST_ASSERT(!r || r == 1, KVM_IOCTL_ERROR(KVM_SET_MSRS, r)); + TEST_ASSERT(r != 1 || xss_in_msr_list, + "IA32_XSS was able to be set, but was not in save/restore list"); + } + + kvm_vm_free(vm); +} |