1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Test for x86 KVM_CAP_HYPERV_CPUID
4  *
5  * Copyright (C) 2018, Red Hat, Inc.
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2.
8  *
9  */
10 
11 #define _GNU_SOURCE /* for program_invocation_short_name */
12 #include <fcntl.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <sys/ioctl.h>
17 
18 #include "test_util.h"
19 #include "kvm_util.h"
20 #include "processor.h"
21 #include "vmx.h"
22 
23 #define VCPU_ID 0
24 
25 static void guest_code(void)
26 {
27 }
28 
29 static int smt_possible(void)
30 {
31 	char buf[16];
32 	FILE *f;
33 	bool res = 1;
34 
35 	f = fopen("/sys/devices/system/cpu/smt/control", "r");
36 	if (f) {
37 		if (fread(buf, sizeof(*buf), sizeof(buf), f) > 0) {
38 			if (!strncmp(buf, "forceoff", 8) ||
39 			    !strncmp(buf, "notsupported", 12))
40 				res = 0;
41 		}
42 		fclose(f);
43 	}
44 
45 	return res;
46 }
47 
48 static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
49 			  int evmcs_enabled)
50 {
51 	int i;
52 
53 	if (!evmcs_enabled)
54 		TEST_ASSERT(hv_cpuid_entries->nent == 6,
55 			    "KVM_GET_SUPPORTED_HV_CPUID should return 6 entries"
56 			    " when Enlightened VMCS is disabled (returned %d)",
57 			    hv_cpuid_entries->nent);
58 	else
59 		TEST_ASSERT(hv_cpuid_entries->nent == 7,
60 			    "KVM_GET_SUPPORTED_HV_CPUID should return 7 entries"
61 			    " when Enlightened VMCS is enabled (returned %d)",
62 			    hv_cpuid_entries->nent);
63 
64 	for (i = 0; i < hv_cpuid_entries->nent; i++) {
65 		struct kvm_cpuid_entry2 *entry = &hv_cpuid_entries->entries[i];
66 
67 		TEST_ASSERT((entry->function >= 0x40000000) &&
68 			    (entry->function <= 0x4000000A),
69 			    "function %x is our of supported range",
70 			    entry->function);
71 
72 		TEST_ASSERT(entry->index == 0,
73 			    ".index field should be zero");
74 
75 		TEST_ASSERT(entry->flags == 0,
76 			    ".flags field should be zero");
77 
78 		TEST_ASSERT(!entry->padding[0] && !entry->padding[1] &&
79 			    !entry->padding[2], "padding should be zero");
80 
81 		if (entry->function == 0x40000004) {
82 			int nononarchcs = !!(entry->eax & (1UL << 18));
83 
84 			TEST_ASSERT(nononarchcs == !smt_possible(),
85 				    "NoNonArchitecturalCoreSharing bit"
86 				    " doesn't reflect SMT setting");
87 		}
88 
89 		/*
90 		 * If needed for debug:
91 		 * fprintf(stdout,
92 		 *	"CPUID%lx EAX=0x%lx EBX=0x%lx ECX=0x%lx EDX=0x%lx\n",
93 		 *	entry->function, entry->eax, entry->ebx, entry->ecx,
94 		 *	entry->edx);
95 		 */
96 	}
97 
98 }
99 
100 void test_hv_cpuid_e2big(struct kvm_vm *vm)
101 {
102 	static struct kvm_cpuid2 cpuid = {.nent = 0};
103 	int ret;
104 
105 	ret = _vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, &cpuid);
106 
107 	TEST_ASSERT(ret == -1 && errno == E2BIG,
108 		    "KVM_GET_SUPPORTED_HV_CPUID didn't fail with -E2BIG when"
109 		    " it should have: %d %d", ret, errno);
110 }
111 
112 
113 struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(struct kvm_vm *vm)
114 {
115 	int nent = 20; /* should be enough */
116 	static struct kvm_cpuid2 *cpuid;
117 
118 	cpuid = malloc(sizeof(*cpuid) + nent * sizeof(struct kvm_cpuid_entry2));
119 
120 	if (!cpuid) {
121 		perror("malloc");
122 		abort();
123 	}
124 
125 	cpuid->nent = nent;
126 
127 	vcpu_ioctl(vm, VCPU_ID, KVM_GET_SUPPORTED_HV_CPUID, cpuid);
128 
129 	return cpuid;
130 }
131 
132 
133 int main(int argc, char *argv[])
134 {
135 	struct kvm_vm *vm;
136 	int rv;
137 	struct kvm_cpuid2 *hv_cpuid_entries;
138 
139 	/* Tell stdout not to buffer its content */
140 	setbuf(stdout, NULL);
141 
142 	rv = kvm_check_cap(KVM_CAP_HYPERV_CPUID);
143 	if (!rv) {
144 		print_skip("KVM_CAP_HYPERV_CPUID not supported");
145 		exit(KSFT_SKIP);
146 	}
147 
148 	/* Create VM */
149 	vm = vm_create_default(VCPU_ID, 0, guest_code);
150 
151 	test_hv_cpuid_e2big(vm);
152 
153 	hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm);
154 	if (!hv_cpuid_entries)
155 		return 1;
156 
157 	test_hv_cpuid(hv_cpuid_entries, 0);
158 
159 	free(hv_cpuid_entries);
160 
161 	if (!kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
162 		print_skip("Enlightened VMCS is unsupported");
163 		goto vm_free;
164 	}
165 
166 	vcpu_enable_evmcs(vm, VCPU_ID);
167 
168 	hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm);
169 	if (!hv_cpuid_entries)
170 		return 1;
171 
172 	test_hv_cpuid(hv_cpuid_entries, 1);
173 
174 	free(hv_cpuid_entries);
175 
176 vm_free:
177 	kvm_vm_free(vm);
178 
179 	return 0;
180 }
181