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 MSR_BITS 64 16 main(int argc,char * argv[])17 int main(int argc, char *argv[]) 18 { 19 bool xss_in_msr_list; 20 struct kvm_vm *vm; 21 struct kvm_vcpu *vcpu; 22 uint64_t xss_val; 23 int i, r; 24 25 /* Create VM */ 26 vm = vm_create_with_one_vcpu(&vcpu, NULL); 27 28 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVES)); 29 30 xss_val = vcpu_get_msr(vcpu, MSR_IA32_XSS); 31 TEST_ASSERT(xss_val == 0, 32 "MSR_IA32_XSS should be initialized to zero\n"); 33 34 vcpu_set_msr(vcpu, MSR_IA32_XSS, xss_val); 35 36 /* 37 * At present, KVM only supports a guest IA32_XSS value of 0. Verify 38 * that trying to set the guest IA32_XSS to an unsupported value fails. 39 * Also, in the future when a non-zero value succeeds check that 40 * IA32_XSS is in the list of MSRs to save/restore. 41 */ 42 xss_in_msr_list = kvm_msr_is_in_save_restore_list(MSR_IA32_XSS); 43 for (i = 0; i < MSR_BITS; ++i) { 44 r = _vcpu_set_msr(vcpu, MSR_IA32_XSS, 1ull << i); 45 46 /* 47 * Setting a list of MSRs returns the entry that "faulted", or 48 * the last entry +1 if all MSRs were successfully written. 49 */ 50 TEST_ASSERT(!r || r == 1, KVM_IOCTL_ERROR(KVM_SET_MSRS, r)); 51 TEST_ASSERT(r != 1 || xss_in_msr_list, 52 "IA32_XSS was able to be set, but was not in save/restore list"); 53 } 54 55 kvm_vm_free(vm); 56 } 57