linux/tools/testing/selftests/kvm/x86_64/xss_msr_test.c

77 lines
1.8 KiB
C

// 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);
}