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_run *run;
54 	struct kvm_vm *vm;
55 	struct kvm_sregs sregs;
56 	struct ucall uc;
57 
58 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVE));
59 
60 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
61 	run = vcpu->run;
62 
63 	while (1) {
64 		vcpu_run(vcpu);
65 
66 		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
67 			    "Unexpected exit reason: %u (%s),\n",
68 			    run->exit_reason,
69 			    exit_reason_str(run->exit_reason));
70 
71 		switch (get_ucall(vcpu, &uc)) {
72 		case UCALL_SYNC:
73 			/* emulate hypervisor clearing CR4.OSXSAVE */
74 			vcpu_sregs_get(vcpu, &sregs);
75 			sregs.cr4 &= ~X86_CR4_OSXSAVE;
76 			vcpu_sregs_set(vcpu, &sregs);
77 			break;
78 		case UCALL_ABORT:
79 			REPORT_GUEST_ASSERT(uc);
80 			break;
81 		case UCALL_DONE:
82 			goto done;
83 		default:
84 			TEST_FAIL("Unknown ucall %lu", uc.cmd);
85 		}
86 	}
87 
88 done:
89 	kvm_vm_free(vm);
90 	return 0;
91 }
92