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
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