xref: /linux/tools/testing/selftests/kvm/x86_64/cpuid_test.c (revision c34e9ab9a612ee8b18273398ef75c207b01f516d)
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 struct cpuid_mask {
16 	union {
17 		struct {
18 			u32 eax;
19 			u32 ebx;
20 			u32 ecx;
21 			u32 edx;
22 		};
23 		u32 regs[4];
24 	};
25 };
26 
27 static void test_guest_cpuids(struct kvm_cpuid2 *guest_cpuid)
28 {
29 	int i;
30 	u32 eax, ebx, ecx, edx;
31 
32 	for (i = 0; i < guest_cpuid->nent; i++) {
33 		__cpuid(guest_cpuid->entries[i].function,
34 			guest_cpuid->entries[i].index,
35 			&eax, &ebx, &ecx, &edx);
36 
37 		GUEST_ASSERT_EQ(eax, guest_cpuid->entries[i].eax);
38 		GUEST_ASSERT_EQ(ebx, guest_cpuid->entries[i].ebx);
39 		GUEST_ASSERT_EQ(ecx, guest_cpuid->entries[i].ecx);
40 		GUEST_ASSERT_EQ(edx, guest_cpuid->entries[i].edx);
41 	}
42 
43 }
44 
45 static void guest_main(struct kvm_cpuid2 *guest_cpuid)
46 {
47 	GUEST_SYNC(1);
48 
49 	test_guest_cpuids(guest_cpuid);
50 
51 	GUEST_SYNC(2);
52 
53 	GUEST_ASSERT_EQ(this_cpu_property(X86_PROPERTY_MAX_KVM_LEAF), 0x40000001);
54 
55 	GUEST_DONE();
56 }
57 
58 static struct cpuid_mask get_const_cpuid_mask(const struct kvm_cpuid_entry2 *entry)
59 {
60 	struct cpuid_mask mask;
61 
62 	memset(&mask, 0xff, sizeof(mask));
63 
64 	switch (entry->function) {
65 	case 0x1:
66 		mask.regs[X86_FEATURE_OSXSAVE.reg] &= ~BIT(X86_FEATURE_OSXSAVE.bit);
67 		break;
68 	case 0x7:
69 		mask.regs[X86_FEATURE_OSPKE.reg] &= ~BIT(X86_FEATURE_OSPKE.bit);
70 		break;
71 	case 0xd:
72 		/*
73 		 * CPUID.0xD.{0,1}.EBX enumerate XSAVE size based on the current
74 		 * XCR0 and IA32_XSS MSR values.
75 		 */
76 		if (entry->index < 2)
77 			mask.ebx = 0;
78 		break;
79 	}
80 	return mask;
81 }
82 
83 static void compare_cpuids(const struct kvm_cpuid2 *cpuid1,
84 			   const struct kvm_cpuid2 *cpuid2)
85 {
86 	const struct kvm_cpuid_entry2 *e1, *e2;
87 	int i;
88 
89 	TEST_ASSERT(cpuid1->nent == cpuid2->nent,
90 		    "CPUID nent mismatch: %d vs. %d", cpuid1->nent, cpuid2->nent);
91 
92 	for (i = 0; i < cpuid1->nent; i++) {
93 		struct cpuid_mask mask;
94 
95 		e1 = &cpuid1->entries[i];
96 		e2 = &cpuid2->entries[i];
97 
98 		TEST_ASSERT(e1->function == e2->function &&
99 			    e1->index == e2->index && e1->flags == e2->flags,
100 			    "CPUID entries[%d] mismtach: 0x%x.%d.%x vs. 0x%x.%d.%x",
101 			    i, e1->function, e1->index, e1->flags,
102 			    e2->function, e2->index, e2->flags);
103 
104 		/* Mask off dynamic bits, e.g. OSXSAVE, when comparing entries. */
105 		mask = get_const_cpuid_mask(e1);
106 
107 		TEST_ASSERT((e1->eax & mask.eax) == (e2->eax & mask.eax) &&
108 			    (e1->ebx & mask.ebx) == (e2->ebx & mask.ebx) &&
109 			    (e1->ecx & mask.ecx) == (e2->ecx & mask.ecx) &&
110 			    (e1->edx & mask.edx) == (e2->edx & mask.edx),
111 			    "CPUID 0x%x.%x differ: 0x%x:0x%x:0x%x:0x%x vs 0x%x:0x%x:0x%x:0x%x",
112 			    e1->function, e1->index,
113 			    e1->eax & mask.eax, e1->ebx & mask.ebx,
114 			    e1->ecx & mask.ecx, e1->edx & mask.edx,
115 			    e2->eax & mask.eax, e2->ebx & mask.ebx,
116 			    e2->ecx & mask.ecx, e2->edx & mask.edx);
117 	}
118 }
119 
120 static void run_vcpu(struct kvm_vcpu *vcpu, int stage)
121 {
122 	struct ucall uc;
123 
124 	vcpu_run(vcpu);
125 
126 	switch (get_ucall(vcpu, &uc)) {
127 	case UCALL_SYNC:
128 		TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
129 			    uc.args[1] == stage + 1,
130 			    "Stage %d: Unexpected register values vmexit, got %lx",
131 			    stage + 1, (ulong)uc.args[1]);
132 		return;
133 	case UCALL_DONE:
134 		return;
135 	case UCALL_ABORT:
136 		REPORT_GUEST_ASSERT(uc);
137 	default:
138 		TEST_ASSERT(false, "Unexpected exit: %s",
139 			    exit_reason_str(vcpu->run->exit_reason));
140 	}
141 }
142 
143 struct kvm_cpuid2 *vcpu_alloc_cpuid(struct kvm_vm *vm, vm_vaddr_t *p_gva, struct kvm_cpuid2 *cpuid)
144 {
145 	int size = sizeof(*cpuid) + cpuid->nent * sizeof(cpuid->entries[0]);
146 	vm_vaddr_t gva = vm_vaddr_alloc(vm, size, KVM_UTIL_MIN_VADDR);
147 	struct kvm_cpuid2 *guest_cpuids = addr_gva2hva(vm, gva);
148 
149 	memcpy(guest_cpuids, cpuid, size);
150 
151 	*p_gva = gva;
152 	return guest_cpuids;
153 }
154 
155 static void set_cpuid_after_run(struct kvm_vcpu *vcpu)
156 {
157 	struct kvm_cpuid_entry2 *ent;
158 	int rc;
159 	u32 eax, ebx, x;
160 
161 	/* Setting unmodified CPUID is allowed */
162 	rc = __vcpu_set_cpuid(vcpu);
163 	TEST_ASSERT(!rc, "Setting unmodified CPUID after KVM_RUN failed: %d", rc);
164 
165 	/* Changing CPU features is forbidden */
166 	ent = vcpu_get_cpuid_entry(vcpu, 0x7);
167 	ebx = ent->ebx;
168 	ent->ebx--;
169 	rc = __vcpu_set_cpuid(vcpu);
170 	TEST_ASSERT(rc, "Changing CPU features should fail");
171 	ent->ebx = ebx;
172 
173 	/* Changing MAXPHYADDR is forbidden */
174 	ent = vcpu_get_cpuid_entry(vcpu, 0x80000008);
175 	eax = ent->eax;
176 	x = eax & 0xff;
177 	ent->eax = (eax & ~0xffu) | (x - 1);
178 	rc = __vcpu_set_cpuid(vcpu);
179 	TEST_ASSERT(rc, "Changing MAXPHYADDR should fail");
180 	ent->eax = eax;
181 }
182 
183 static void test_get_cpuid2(struct kvm_vcpu *vcpu)
184 {
185 	struct kvm_cpuid2 *cpuid = allocate_kvm_cpuid2(vcpu->cpuid->nent + 1);
186 	int i, r;
187 
188 	vcpu_ioctl(vcpu, KVM_GET_CPUID2, cpuid);
189 	TEST_ASSERT(cpuid->nent == vcpu->cpuid->nent,
190 		    "KVM didn't update nent on success, wanted %u, got %u",
191 		    vcpu->cpuid->nent, cpuid->nent);
192 
193 	for (i = 0; i < vcpu->cpuid->nent; i++) {
194 		cpuid->nent = i;
195 		r = __vcpu_ioctl(vcpu, KVM_GET_CPUID2, cpuid);
196 		TEST_ASSERT(r && errno == E2BIG, KVM_IOCTL_ERROR(KVM_GET_CPUID2, r));
197 		TEST_ASSERT(cpuid->nent == i, "KVM modified nent on failure");
198 	}
199 	free(cpuid);
200 }
201 
202 int main(void)
203 {
204 	struct kvm_vcpu *vcpu;
205 	vm_vaddr_t cpuid_gva;
206 	struct kvm_vm *vm;
207 	int stage;
208 
209 	vm = vm_create_with_one_vcpu(&vcpu, guest_main);
210 
211 	compare_cpuids(kvm_get_supported_cpuid(), vcpu->cpuid);
212 
213 	vcpu_alloc_cpuid(vm, &cpuid_gva, vcpu->cpuid);
214 
215 	vcpu_args_set(vcpu, 1, cpuid_gva);
216 
217 	for (stage = 0; stage < 3; stage++)
218 		run_vcpu(vcpu, stage);
219 
220 	set_cpuid_after_run(vcpu);
221 
222 	test_get_cpuid2(vcpu);
223 
224 	kvm_vm_free(vm);
225 }
226