1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * CR4 and CPUID sync test
4  *
5  * Copyright 2018, Red Hat, Inc. and/or its affiliates.
6  *
7  * Author:
8  *   Wei Huang <wei@redhat.com>
9  */
10 
11 #include <fcntl.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <sys/ioctl.h>
16 
17 #include "test_util.h"
18 
19 #include "kvm_util.h"
20 #include "processor.h"
21 
22 static inline bool cr4_cpuid_is_sync(void)
23 {
24 	uint64_t cr4 = get_cr4();
25 
26 	return (this_cpu_has(X86_FEATURE_OSXSAVE) == !!(cr4 & X86_CR4_OSXSAVE));
27 }
28 
29 static void guest_code(void)
30 {
31 	uint64_t cr4;
32 
33 	/* turn on CR4.OSXSAVE */
34 	cr4 = get_cr4();
35 	cr4 |= X86_CR4_OSXSAVE;
36 	set_cr4(cr4);
37 
38 	/* verify CR4.OSXSAVE == CPUID.OSXSAVE */
39 	GUEST_ASSERT(cr4_cpuid_is_sync());
40 
41 	/* notify hypervisor to change CR4 */
42 	GUEST_SYNC(0);
43 
44 	/* check again */
45 	GUEST_ASSERT(cr4_cpuid_is_sync());
46 
47 	GUEST_DONE();
48 }
49 
50 int main(int argc, char *argv[])
51 {
52 	struct kvm_vcpu *vcpu;
53 	struct kvm_vm *vm;
54 	struct kvm_sregs sregs;
55 	struct ucall uc;
56 
57 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVE));
58 
59 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
60 
61 	while (1) {
62 		vcpu_run(vcpu);
63 		TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
64 
65 		switch (get_ucall(vcpu, &uc)) {
66 		case UCALL_SYNC:
67 			/* emulate hypervisor clearing CR4.OSXSAVE */
68 			vcpu_sregs_get(vcpu, &sregs);
69 			sregs.cr4 &= ~X86_CR4_OSXSAVE;
70 			vcpu_sregs_set(vcpu, &sregs);
71 			break;
72 		case UCALL_ABORT:
73 			REPORT_GUEST_ASSERT(uc);
74 			break;
75 		case UCALL_DONE:
76 			goto done;
77 		default:
78 			TEST_FAIL("Unknown ucall %lu", uc.cmd);
79 		}
80 	}
81 
82 done:
83 	kvm_vm_free(vm);
84 	return 0;
85 }
86