xref: /linux/tools/testing/selftests/kvm/x86_64/cpuid_test.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2021, Red Hat Inc.
4  *
5  * Generic tests for KVM CPUID set/get ioctls
6  */
7 #include <asm/kvm_para.h>
8 #include <linux/kvm_para.h>
9 #include <stdint.h>
10 
11 #include "test_util.h"
12 #include "kvm_util.h"
13 #include "processor.h"
14 
15 /* CPUIDs known to differ */
16 struct {
17 	u32 function;
18 	u32 index;
19 } mangled_cpuids[] = {
20 	/*
21 	 * These entries depend on the vCPU's XCR0 register and IA32_XSS MSR,
22 	 * which are not controlled for by this test.
23 	 */
24 	{.function = 0xd, .index = 0},
25 	{.function = 0xd, .index = 1},
26 };
27 
28 static void test_guest_cpuids(struct kvm_cpuid2 *guest_cpuid)
29 {
30 	int i;
31 	u32 eax, ebx, ecx, edx;
32 
33 	for (i = 0; i < guest_cpuid->nent; i++) {
34 		__cpuid(guest_cpuid->entries[i].function,
35 			guest_cpuid->entries[i].index,
36 			&eax, &ebx, &ecx, &edx);
37 
38 		GUEST_ASSERT_EQ(eax, guest_cpuid->entries[i].eax);
39 		GUEST_ASSERT_EQ(ebx, guest_cpuid->entries[i].ebx);
40 		GUEST_ASSERT_EQ(ecx, guest_cpuid->entries[i].ecx);
41 		GUEST_ASSERT_EQ(edx, guest_cpuid->entries[i].edx);
42 	}
43 
44 }
45 
46 static void guest_main(struct kvm_cpuid2 *guest_cpuid)
47 {
48 	GUEST_SYNC(1);
49 
50 	test_guest_cpuids(guest_cpuid);
51 
52 	GUEST_SYNC(2);
53 
54 	GUEST_ASSERT_EQ(this_cpu_property(X86_PROPERTY_MAX_KVM_LEAF), 0x40000001);
55 
56 	GUEST_DONE();
57 }
58 
59 static bool is_cpuid_mangled(const struct kvm_cpuid_entry2 *entrie)
60 {
61 	int i;
62 
63 	for (i = 0; i < sizeof(mangled_cpuids); i++) {
64 		if (mangled_cpuids[i].function == entrie->function &&
65 		    mangled_cpuids[i].index == entrie->index)
66 			return true;
67 	}
68 
69 	return false;
70 }
71 
72 static void compare_cpuids(const struct kvm_cpuid2 *cpuid1,
73 			   const struct kvm_cpuid2 *cpuid2)
74 {
75 	const struct kvm_cpuid_entry2 *e1, *e2;
76 	int i;
77 
78 	TEST_ASSERT(cpuid1->nent == cpuid2->nent,
79 		    "CPUID nent mismatch: %d vs. %d", cpuid1->nent, cpuid2->nent);
80 
81 	for (i = 0; i < cpuid1->nent; i++) {
82 		e1 = &cpuid1->entries[i];
83 		e2 = &cpuid2->entries[i];
84 
85 		TEST_ASSERT(e1->function == e2->function &&
86 			    e1->index == e2->index && e1->flags == e2->flags,
87 			    "CPUID entries[%d] mismtach: 0x%x.%d.%x vs. 0x%x.%d.%x",
88 			    i, e1->function, e1->index, e1->flags,
89 			    e2->function, e2->index, e2->flags);
90 
91 		if (is_cpuid_mangled(e1))
92 			continue;
93 
94 		TEST_ASSERT(e1->eax == e2->eax && e1->ebx == e2->ebx &&
95 			    e1->ecx == e2->ecx && e1->edx == e2->edx,
96 			    "CPUID 0x%x.%x differ: 0x%x:0x%x:0x%x:0x%x vs 0x%x:0x%x:0x%x:0x%x",
97 			    e1->function, e1->index,
98 			    e1->eax, e1->ebx, e1->ecx, e1->edx,
99 			    e2->eax, e2->ebx, e2->ecx, e2->edx);
100 	}
101 }
102 
103 static void run_vcpu(struct kvm_vcpu *vcpu, int stage)
104 {
105 	struct ucall uc;
106 
107 	vcpu_run(vcpu);
108 
109 	switch (get_ucall(vcpu, &uc)) {
110 	case UCALL_SYNC:
111 		TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
112 			    uc.args[1] == stage + 1,
113 			    "Stage %d: Unexpected register values vmexit, got %lx",
114 			    stage + 1, (ulong)uc.args[1]);
115 		return;
116 	case UCALL_DONE:
117 		return;
118 	case UCALL_ABORT:
119 		REPORT_GUEST_ASSERT(uc);
120 	default:
121 		TEST_ASSERT(false, "Unexpected exit: %s",
122 			    exit_reason_str(vcpu->run->exit_reason));
123 	}
124 }
125 
126 struct kvm_cpuid2 *vcpu_alloc_cpuid(struct kvm_vm *vm, vm_vaddr_t *p_gva, struct kvm_cpuid2 *cpuid)
127 {
128 	int size = sizeof(*cpuid) + cpuid->nent * sizeof(cpuid->entries[0]);
129 	vm_vaddr_t gva = vm_vaddr_alloc(vm, size, KVM_UTIL_MIN_VADDR);
130 	struct kvm_cpuid2 *guest_cpuids = addr_gva2hva(vm, gva);
131 
132 	memcpy(guest_cpuids, cpuid, size);
133 
134 	*p_gva = gva;
135 	return guest_cpuids;
136 }
137 
138 static void set_cpuid_after_run(struct kvm_vcpu *vcpu)
139 {
140 	struct kvm_cpuid_entry2 *ent;
141 	int rc;
142 	u32 eax, ebx, x;
143 
144 	/* Setting unmodified CPUID is allowed */
145 	rc = __vcpu_set_cpuid(vcpu);
146 	TEST_ASSERT(!rc, "Setting unmodified CPUID after KVM_RUN failed: %d", rc);
147 
148 	/* Changing CPU features is forbidden */
149 	ent = vcpu_get_cpuid_entry(vcpu, 0x7);
150 	ebx = ent->ebx;
151 	ent->ebx--;
152 	rc = __vcpu_set_cpuid(vcpu);
153 	TEST_ASSERT(rc, "Changing CPU features should fail");
154 	ent->ebx = ebx;
155 
156 	/* Changing MAXPHYADDR is forbidden */
157 	ent = vcpu_get_cpuid_entry(vcpu, 0x80000008);
158 	eax = ent->eax;
159 	x = eax & 0xff;
160 	ent->eax = (eax & ~0xffu) | (x - 1);
161 	rc = __vcpu_set_cpuid(vcpu);
162 	TEST_ASSERT(rc, "Changing MAXPHYADDR should fail");
163 	ent->eax = eax;
164 }
165 
166 static void test_get_cpuid2(struct kvm_vcpu *vcpu)
167 {
168 	struct kvm_cpuid2 *cpuid = allocate_kvm_cpuid2(vcpu->cpuid->nent + 1);
169 	int i, r;
170 
171 	vcpu_ioctl(vcpu, KVM_GET_CPUID2, cpuid);
172 	TEST_ASSERT(cpuid->nent == vcpu->cpuid->nent,
173 		    "KVM didn't update nent on success, wanted %u, got %u",
174 		    vcpu->cpuid->nent, cpuid->nent);
175 
176 	for (i = 0; i < vcpu->cpuid->nent; i++) {
177 		cpuid->nent = i;
178 		r = __vcpu_ioctl(vcpu, KVM_GET_CPUID2, cpuid);
179 		TEST_ASSERT(r && errno == E2BIG, KVM_IOCTL_ERROR(KVM_GET_CPUID2, r));
180 		TEST_ASSERT(cpuid->nent == i, "KVM modified nent on failure");
181 	}
182 	free(cpuid);
183 }
184 
185 int main(void)
186 {
187 	struct kvm_vcpu *vcpu;
188 	vm_vaddr_t cpuid_gva;
189 	struct kvm_vm *vm;
190 	int stage;
191 
192 	vm = vm_create_with_one_vcpu(&vcpu, guest_main);
193 
194 	compare_cpuids(kvm_get_supported_cpuid(), vcpu->cpuid);
195 
196 	vcpu_alloc_cpuid(vm, &cpuid_gva, vcpu->cpuid);
197 
198 	vcpu_args_set(vcpu, 1, cpuid_gva);
199 
200 	for (stage = 0; stage < 3; stage++)
201 		run_vcpu(vcpu, stage);
202 
203 	set_cpuid_after_run(vcpu);
204 
205 	test_get_cpuid2(vcpu);
206 
207 	kvm_vm_free(vm);
208 }
209