// 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 MSR_BITS 64 int main(int argc, char *argv[]) { bool xss_in_msr_list; struct kvm_vm *vm; struct kvm_vcpu *vcpu; uint64_t xss_val; int i, r; /* Create VM */ vm = vm_create_with_one_vcpu(&vcpu, NULL); TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVES)); xss_val = vcpu_get_msr(vcpu, MSR_IA32_XSS); TEST_ASSERT(xss_val == 0, "MSR_IA32_XSS should be initialized to zero\n"); vcpu_set_msr(vcpu, 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 list of MSRs to save/restore. */ xss_in_msr_list = kvm_msr_is_in_save_restore_list(MSR_IA32_XSS); for (i = 0; i < MSR_BITS; ++i) { r = _vcpu_set_msr(vcpu, MSR_IA32_XSS, 1ull << i); /* * Setting a list of MSRs returns the entry that "faulted", or * the last entry +1 if all MSRs were successfully written. */ TEST_ASSERT(!r || r == 1, KVM_IOCTL_ERROR(KVM_SET_MSRS, r)); TEST_ASSERT(r != 1 || xss_in_msr_list, "IA32_XSS was able to be set, but was not in save/restore list"); } kvm_vm_free(vm); }