1 // SPDX-License-Identifier: GPL-2.0
3 * CR4 and CPUID sync test
5 * Copyright 2018, Red Hat, Inc. and/or its affiliates.
8 * Wei Huang <wei@redhat.com>
15 #include <sys/ioctl.h>
17 #include "test_util.h"
20 #include "processor.h"
22 #define X86_FEATURE_XSAVE (1<<26)
23 #define X86_FEATURE_OSXSAVE (1<<27)
26 static inline bool cr4_cpuid_is_sync(void)
29 uint32_t eax, ebx, ecx, edx;
34 __asm__ __volatile__("cpuid"
35 : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
36 : "a"(func), "c"(subfunc));
40 return (!!(ecx & X86_FEATURE_OSXSAVE)) == (!!(cr4 & X86_CR4_OSXSAVE));
43 static void guest_code(void)
47 /* turn on CR4.OSXSAVE */
49 cr4 |= X86_CR4_OSXSAVE;
52 /* verify CR4.OSXSAVE == CPUID.OSXSAVE */
53 GUEST_ASSERT(cr4_cpuid_is_sync());
55 /* notify hypervisor to change CR4 */
59 GUEST_ASSERT(cr4_cpuid_is_sync());
64 int main(int argc, char *argv[])
68 struct kvm_sregs sregs;
69 struct kvm_cpuid_entry2 *entry;
73 entry = kvm_get_supported_cpuid_entry(1);
74 if (!(entry->ecx & X86_FEATURE_XSAVE)) {
75 printf("XSAVE feature not supported, skipping test\n");
79 /* Tell stdout not to buffer its content */
83 vm = vm_create_default(VCPU_ID, 0, guest_code);
84 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
85 run = vcpu_state(vm, VCPU_ID);
88 rc = _vcpu_run(vm, VCPU_ID);
90 if (run->exit_reason == KVM_EXIT_IO) {
91 switch (get_ucall(vm, VCPU_ID, &uc)) {
93 /* emulate hypervisor clearing CR4.OSXSAVE */
94 vcpu_sregs_get(vm, VCPU_ID, &sregs);
95 sregs.cr4 &= ~X86_CR4_OSXSAVE;
96 vcpu_sregs_set(vm, VCPU_ID, &sregs);
99 TEST_ASSERT(false, "Guest CR4 bit (OSXSAVE) unsynchronized with CPUID bit.");
104 TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd);