1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2019, Google LLC. 4 * 5 * Tests for the IA32_XSS MSR. 6 */ 7 #include <sys/ioctl.h> 8 9 #include "test_util.h" 10 #include "kvm_util.h" 11 #include "vmx.h" 12 13 #define MSR_BITS 64 14 15 int main(int argc, char *argv[]) 16 { 17 bool xss_in_msr_list; 18 struct kvm_vm *vm; 19 struct kvm_vcpu *vcpu; 20 uint64_t xss_val; 21 int i, r; 22 23 /* Create VM */ 24 vm = vm_create_with_one_vcpu(&vcpu, NULL); 25 26 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVES)); 27 28 xss_val = vcpu_get_msr(vcpu, MSR_IA32_XSS); 29 TEST_ASSERT(xss_val == 0, 30 "MSR_IA32_XSS should be initialized to zero"); 31 32 vcpu_set_msr(vcpu, MSR_IA32_XSS, xss_val); 33 34 /* 35 * At present, KVM only supports a guest IA32_XSS value of 0. Verify 36 * that trying to set the guest IA32_XSS to an unsupported value fails. 37 * Also, in the future when a non-zero value succeeds check that 38 * IA32_XSS is in the list of MSRs to save/restore. 39 */ 40 xss_in_msr_list = kvm_msr_is_in_save_restore_list(MSR_IA32_XSS); 41 for (i = 0; i < MSR_BITS; ++i) { 42 r = _vcpu_set_msr(vcpu, MSR_IA32_XSS, 1ull << i); 43 44 /* 45 * Setting a list of MSRs returns the entry that "faulted", or 46 * the last entry +1 if all MSRs were successfully written. 47 */ 48 TEST_ASSERT(!r || r == 1, KVM_IOCTL_ERROR(KVM_SET_MSRS, r)); 49 TEST_ASSERT(r != 1 || xss_in_msr_list, 50 "IA32_XSS was able to be set, but was not in save/restore list"); 51 } 52 53 kvm_vm_free(vm); 54 } 55