1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Test for x86 KVM_CAP_MSR_PLATFORM_INFO
4  *
5  * Copyright (C) 2018, Google LLC.
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2.
8  *
9  * Verifies expected behavior of controlling guest access to
10  * MSR_PLATFORM_INFO.
11  */
12 
13 #define _GNU_SOURCE /* for program_invocation_short_name */
14 #include <fcntl.h>
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include <string.h>
18 #include <sys/ioctl.h>
19 
20 #include "test_util.h"
21 #include "kvm_util.h"
22 #include "processor.h"
23 
24 #define VCPU_ID 0
25 #define MSR_PLATFORM_INFO_MAX_TURBO_RATIO 0xff00
26 
guest_code(void)27 static void guest_code(void)
28 {
29 	uint64_t msr_platform_info;
30 
31 	for (;;) {
32 		msr_platform_info = rdmsr(MSR_PLATFORM_INFO);
33 		GUEST_SYNC(msr_platform_info);
34 		asm volatile ("inc %r11");
35 	}
36 }
37 
set_msr_platform_info_enabled(struct kvm_vm * vm,bool enable)38 static void set_msr_platform_info_enabled(struct kvm_vm *vm, bool enable)
39 {
40 	struct kvm_enable_cap cap = {};
41 
42 	cap.cap = KVM_CAP_MSR_PLATFORM_INFO;
43 	cap.flags = 0;
44 	cap.args[0] = (int)enable;
45 	vm_enable_cap(vm, &cap);
46 }
47 
test_msr_platform_info_enabled(struct kvm_vm * vm)48 static void test_msr_platform_info_enabled(struct kvm_vm *vm)
49 {
50 	struct kvm_run *run = vcpu_state(vm, VCPU_ID);
51 	struct ucall uc;
52 
53 	set_msr_platform_info_enabled(vm, true);
54 	vcpu_run(vm, VCPU_ID);
55 	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
56 			"Exit_reason other than KVM_EXIT_IO: %u (%s),\n",
57 			run->exit_reason,
58 			exit_reason_str(run->exit_reason));
59 	get_ucall(vm, VCPU_ID, &uc);
60 	TEST_ASSERT(uc.cmd == UCALL_SYNC,
61 			"Received ucall other than UCALL_SYNC: %lu\n", uc.cmd);
62 	TEST_ASSERT((uc.args[1] & MSR_PLATFORM_INFO_MAX_TURBO_RATIO) ==
63 		MSR_PLATFORM_INFO_MAX_TURBO_RATIO,
64 		"Expected MSR_PLATFORM_INFO to have max turbo ratio mask: %i.",
65 		MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
66 }
67 
test_msr_platform_info_disabled(struct kvm_vm * vm)68 static void test_msr_platform_info_disabled(struct kvm_vm *vm)
69 {
70 	struct kvm_run *run = vcpu_state(vm, VCPU_ID);
71 
72 	set_msr_platform_info_enabled(vm, false);
73 	vcpu_run(vm, VCPU_ID);
74 	TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
75 			"Exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s)\n",
76 			run->exit_reason,
77 			exit_reason_str(run->exit_reason));
78 }
79 
main(int argc,char * argv[])80 int main(int argc, char *argv[])
81 {
82 	struct kvm_vm *vm;
83 	int rv;
84 	uint64_t msr_platform_info;
85 
86 	/* Tell stdout not to buffer its content */
87 	setbuf(stdout, NULL);
88 
89 	rv = kvm_check_cap(KVM_CAP_MSR_PLATFORM_INFO);
90 	if (!rv) {
91 		print_skip("KVM_CAP_MSR_PLATFORM_INFO not supported");
92 		exit(KSFT_SKIP);
93 	}
94 
95 	vm = vm_create_default(VCPU_ID, 0, guest_code);
96 
97 	msr_platform_info = vcpu_get_msr(vm, VCPU_ID, MSR_PLATFORM_INFO);
98 	vcpu_set_msr(vm, VCPU_ID, MSR_PLATFORM_INFO,
99 		msr_platform_info | MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
100 	test_msr_platform_info_enabled(vm);
101 	test_msr_platform_info_disabled(vm);
102 	vcpu_set_msr(vm, VCPU_ID, MSR_PLATFORM_INFO, msr_platform_info);
103 
104 	kvm_vm_free(vm);
105 
106 	return 0;
107 }
108