tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 "x86.h"
23
24#define VCPU_ID 0
25#define MSR_PLATFORM_INFO_MAX_TURBO_RATIO 0xff00
26
27static 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
38static 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
48static void test_msr_platform_info_enabled(struct kvm_vm *vm)
49{
50 struct kvm_run *run = vcpu_state(vm, VCPU_ID);
51 struct guest_args args;
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 guest_args_read(vm, VCPU_ID, &args);
60 TEST_ASSERT(args.port == GUEST_PORT_SYNC,
61 "Received IO from port other than PORT_HOST_SYNC: %u\n",
62 run->io.port);
63 TEST_ASSERT((args.arg1 & MSR_PLATFORM_INFO_MAX_TURBO_RATIO) ==
64 MSR_PLATFORM_INFO_MAX_TURBO_RATIO,
65 "Expected MSR_PLATFORM_INFO to have max turbo ratio mask: %i.",
66 MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
67}
68
69static void test_msr_platform_info_disabled(struct kvm_vm *vm)
70{
71 struct kvm_run *run = vcpu_state(vm, VCPU_ID);
72
73 set_msr_platform_info_enabled(vm, false);
74 vcpu_run(vm, VCPU_ID);
75 TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
76 "Exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s)\n",
77 run->exit_reason,
78 exit_reason_str(run->exit_reason));
79}
80
81int main(int argc, char *argv[])
82{
83 struct kvm_vm *vm;
84 struct kvm_run *state;
85 int rv;
86 uint64_t msr_platform_info;
87
88 /* Tell stdout not to buffer its content */
89 setbuf(stdout, NULL);
90
91 rv = kvm_check_cap(KVM_CAP_MSR_PLATFORM_INFO);
92 if (!rv) {
93 fprintf(stderr,
94 "KVM_CAP_MSR_PLATFORM_INFO not supported, skip test\n");
95 exit(KSFT_SKIP);
96 }
97
98 vm = vm_create_default(VCPU_ID, 0, guest_code);
99
100 msr_platform_info = vcpu_get_msr(vm, VCPU_ID, MSR_PLATFORM_INFO);
101 vcpu_set_msr(vm, VCPU_ID, MSR_PLATFORM_INFO,
102 msr_platform_info | MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
103 test_msr_platform_info_disabled(vm);
104 test_msr_platform_info_enabled(vm);
105 vcpu_set_msr(vm, VCPU_ID, MSR_PLATFORM_INFO, msr_platform_info);
106
107 kvm_vm_free(vm);
108
109 return 0;
110}