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 MSR_PLATFORM_INFO_MAX_TURBO_RATIO 0xff00
25 
guest_code(void)26 static void guest_code(void)
27 {
28 	uint64_t msr_platform_info;
29 
30 	for (;;) {
31 		msr_platform_info = rdmsr(MSR_PLATFORM_INFO);
32 		GUEST_SYNC(msr_platform_info);
33 		asm volatile ("inc %r11");
34 	}
35 }
36 
test_msr_platform_info_enabled(struct kvm_vcpu * vcpu)37 static void test_msr_platform_info_enabled(struct kvm_vcpu *vcpu)
38 {
39 	struct ucall uc;
40 
41 	vm_enable_cap(vcpu->vm, KVM_CAP_MSR_PLATFORM_INFO, true);
42 	vcpu_run(vcpu);
43 	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
44 
45 	get_ucall(vcpu, &uc);
46 	TEST_ASSERT(uc.cmd == UCALL_SYNC,
47 			"Received ucall other than UCALL_SYNC: %lu\n", uc.cmd);
48 	TEST_ASSERT((uc.args[1] & MSR_PLATFORM_INFO_MAX_TURBO_RATIO) ==
49 		MSR_PLATFORM_INFO_MAX_TURBO_RATIO,
50 		"Expected MSR_PLATFORM_INFO to have max turbo ratio mask: %i.",
51 		MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
52 }
53 
test_msr_platform_info_disabled(struct kvm_vcpu * vcpu)54 static void test_msr_platform_info_disabled(struct kvm_vcpu *vcpu)
55 {
56 	vm_enable_cap(vcpu->vm, KVM_CAP_MSR_PLATFORM_INFO, false);
57 	vcpu_run(vcpu);
58 	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_SHUTDOWN);
59 }
60 
main(int argc,char * argv[])61 int main(int argc, char *argv[])
62 {
63 	struct kvm_vcpu *vcpu;
64 	struct kvm_vm *vm;
65 	uint64_t msr_platform_info;
66 
67 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_MSR_PLATFORM_INFO));
68 
69 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
70 
71 	msr_platform_info = vcpu_get_msr(vcpu, MSR_PLATFORM_INFO);
72 	vcpu_set_msr(vcpu, MSR_PLATFORM_INFO,
73 		     msr_platform_info | MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
74 	test_msr_platform_info_enabled(vcpu);
75 	test_msr_platform_info_disabled(vcpu);
76 	vcpu_set_msr(vcpu, MSR_PLATFORM_INFO, msr_platform_info);
77 
78 	kvm_vm_free(vm);
79 
80 	return 0;
81 }
82