xss_msr_test.c (1793B)
1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (C) 2019, Google LLC. 4 * 5 * Tests for the IA32_XSS MSR. 6 */ 7 8#define _GNU_SOURCE /* for program_invocation_short_name */ 9#include <sys/ioctl.h> 10 11#include "test_util.h" 12#include "kvm_util.h" 13#include "vmx.h" 14 15#define VCPU_ID 1 16#define MSR_BITS 64 17 18#define X86_FEATURE_XSAVES (1<<3) 19 20bool is_supported_msr(u32 msr_index) 21{ 22 struct kvm_msr_list *list; 23 bool found = false; 24 int i; 25 26 list = kvm_get_msr_index_list(); 27 for (i = 0; i < list->nmsrs; ++i) { 28 if (list->indices[i] == msr_index) { 29 found = true; 30 break; 31 } 32 } 33 34 free(list); 35 return found; 36} 37 38int main(int argc, char *argv[]) 39{ 40 struct kvm_cpuid_entry2 *entry; 41 bool xss_supported = false; 42 struct kvm_vm *vm; 43 uint64_t xss_val; 44 int i, r; 45 46 /* Create VM */ 47 vm = vm_create_default(VCPU_ID, 0, 0); 48 49 if (kvm_get_cpuid_max_basic() >= 0xd) { 50 entry = kvm_get_supported_cpuid_index(0xd, 1); 51 xss_supported = entry && !!(entry->eax & X86_FEATURE_XSAVES); 52 } 53 if (!xss_supported) { 54 print_skip("IA32_XSS is not supported by the vCPU"); 55 exit(KSFT_SKIP); 56 } 57 58 xss_val = vcpu_get_msr(vm, VCPU_ID, MSR_IA32_XSS); 59 TEST_ASSERT(xss_val == 0, 60 "MSR_IA32_XSS should be initialized to zero\n"); 61 62 vcpu_set_msr(vm, VCPU_ID, MSR_IA32_XSS, xss_val); 63 /* 64 * At present, KVM only supports a guest IA32_XSS value of 0. Verify 65 * that trying to set the guest IA32_XSS to an unsupported value fails. 66 * Also, in the future when a non-zero value succeeds check that 67 * IA32_XSS is in the KVM_GET_MSR_INDEX_LIST. 68 */ 69 for (i = 0; i < MSR_BITS; ++i) { 70 r = _vcpu_set_msr(vm, VCPU_ID, MSR_IA32_XSS, 1ull << i); 71 TEST_ASSERT(r == 0 || is_supported_msr(MSR_IA32_XSS), 72 "IA32_XSS was able to be set, but was not found in KVM_GET_MSR_INDEX_LIST.\n"); 73 } 74 75 kvm_vm_free(vm); 76}