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Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/xss_msr_test.c | 76 |
1 files changed, 76 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 000000000..352937674 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/xss_msr_test.c @@ -0,0 +1,76 @@ +// 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 VCPU_ID 1 +#define MSR_BITS 64 + +#define X86_FEATURE_XSAVES (1<<3) + +bool is_supported_msr(u32 msr_index) +{ + struct kvm_msr_list *list; + bool found = false; + int i; + + list = kvm_get_msr_index_list(); + for (i = 0; i < list->nmsrs; ++i) { + if (list->indices[i] == msr_index) { + found = true; + break; + } + } + + free(list); + return found; +} + +int main(int argc, char *argv[]) +{ + struct kvm_cpuid_entry2 *entry; + bool xss_supported = false; + struct kvm_vm *vm; + uint64_t xss_val; + int i, r; + + /* Create VM */ + vm = vm_create_default(VCPU_ID, 0, 0); + + if (kvm_get_cpuid_max_basic() >= 0xd) { + entry = kvm_get_supported_cpuid_index(0xd, 1); + xss_supported = entry && !!(entry->eax & X86_FEATURE_XSAVES); + } + if (!xss_supported) { + print_skip("IA32_XSS is not supported by the vCPU"); + exit(KSFT_SKIP); + } + + xss_val = vcpu_get_msr(vm, VCPU_ID, MSR_IA32_XSS); + TEST_ASSERT(xss_val == 0, + "MSR_IA32_XSS should be initialized to zero\n"); + + vcpu_set_msr(vm, VCPU_ID, 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 KVM_GET_MSR_INDEX_LIST. + */ + for (i = 0; i < MSR_BITS; ++i) { + r = _vcpu_set_msr(vm, VCPU_ID, MSR_IA32_XSS, 1ull << i); + TEST_ASSERT(r == 0 || is_supported_msr(MSR_IA32_XSS), + "IA32_XSS was able to be set, but was not found in KVM_GET_MSR_INDEX_LIST.\n"); + } + + kvm_vm_free(vm); +} |