1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * vmx_set_nested_state_test
4  *
5  * Copyright (C) 2019, Google LLC.
6  *
7  * This test verifies the integrity of calling the ioctl KVM_SET_NESTED_STATE.
8  */
9 
10 #include "test_util.h"
11 #include "kvm_util.h"
12 #include "processor.h"
13 #include "vmx.h"
14 
15 #include <errno.h>
16 #include <linux/kvm.h>
17 #include <string.h>
18 #include <sys/ioctl.h>
19 #include <unistd.h>
20 
21 /*
22  * Mirror of VMCS12_REVISION in arch/x86/kvm/vmx/vmcs12.h. If that value
23  * changes this should be updated.
24  */
25 #define VMCS12_REVISION 0x11e57ed0
26 
27 bool have_evmcs;
28 
29 void test_nested_state(struct kvm_vcpu *vcpu, struct kvm_nested_state *state)
30 {
31 	vcpu_nested_state_set(vcpu, state);
32 }
33 
34 void test_nested_state_expect_errno(struct kvm_vcpu *vcpu,
35 				    struct kvm_nested_state *state,
36 				    int expected_errno)
37 {
38 	int rv;
39 
40 	rv = __vcpu_nested_state_set(vcpu, state);
41 	TEST_ASSERT(rv == -1 && errno == expected_errno,
42 		"Expected %s (%d) from vcpu_nested_state_set but got rv: %i errno: %s (%d)",
43 		strerror(expected_errno), expected_errno, rv, strerror(errno),
44 		errno);
45 }
46 
47 void test_nested_state_expect_einval(struct kvm_vcpu *vcpu,
48 				     struct kvm_nested_state *state)
49 {
50 	test_nested_state_expect_errno(vcpu, state, EINVAL);
51 }
52 
53 void test_nested_state_expect_efault(struct kvm_vcpu *vcpu,
54 				     struct kvm_nested_state *state)
55 {
56 	test_nested_state_expect_errno(vcpu, state, EFAULT);
57 }
58 
59 void set_revision_id_for_vmcs12(struct kvm_nested_state *state,
60 				u32 vmcs12_revision)
61 {
62 	/* Set revision_id in vmcs12 to vmcs12_revision. */
63 	memcpy(&state->data, &vmcs12_revision, sizeof(u32));
64 }
65 
66 void set_default_state(struct kvm_nested_state *state)
67 {
68 	memset(state, 0, sizeof(*state));
69 	state->flags = KVM_STATE_NESTED_RUN_PENDING |
70 		       KVM_STATE_NESTED_GUEST_MODE;
71 	state->format = 0;
72 	state->size = sizeof(*state);
73 }
74 
75 void set_default_vmx_state(struct kvm_nested_state *state, int size)
76 {
77 	memset(state, 0, size);
78 	if (have_evmcs)
79 		state->flags = KVM_STATE_NESTED_EVMCS;
80 	state->format = 0;
81 	state->size = size;
82 	state->hdr.vmx.vmxon_pa = 0x1000;
83 	state->hdr.vmx.vmcs12_pa = 0x2000;
84 	state->hdr.vmx.smm.flags = 0;
85 	set_revision_id_for_vmcs12(state, VMCS12_REVISION);
86 }
87 
88 void test_vmx_nested_state(struct kvm_vcpu *vcpu)
89 {
90 	/* Add a page for VMCS12. */
91 	const int state_sz = sizeof(struct kvm_nested_state) + getpagesize();
92 	struct kvm_nested_state *state =
93 		(struct kvm_nested_state *)malloc(state_sz);
94 
95 	/* The format must be set to 0. 0 for VMX, 1 for SVM. */
96 	set_default_vmx_state(state, state_sz);
97 	state->format = 1;
98 	test_nested_state_expect_einval(vcpu, state);
99 
100 	/*
101 	 * We cannot virtualize anything if the guest does not have VMX
102 	 * enabled.
103 	 */
104 	set_default_vmx_state(state, state_sz);
105 	test_nested_state_expect_einval(vcpu, state);
106 
107 	/*
108 	 * We cannot virtualize anything if the guest does not have VMX
109 	 * enabled.  We expect KVM_SET_NESTED_STATE to return 0 if vmxon_pa
110 	 * is set to -1ull, but the flags must be zero.
111 	 */
112 	set_default_vmx_state(state, state_sz);
113 	state->hdr.vmx.vmxon_pa = -1ull;
114 	test_nested_state_expect_einval(vcpu, state);
115 
116 	state->hdr.vmx.vmcs12_pa = -1ull;
117 	state->flags = KVM_STATE_NESTED_EVMCS;
118 	test_nested_state_expect_einval(vcpu, state);
119 
120 	state->flags = 0;
121 	test_nested_state(vcpu, state);
122 
123 	/* Enable VMX in the guest CPUID. */
124 	vcpu_set_cpuid_feature(vcpu, X86_FEATURE_VMX);
125 
126 	/*
127 	 * Setting vmxon_pa == -1ull and vmcs_pa == -1ull exits early without
128 	 * setting the nested state but flags other than eVMCS must be clear.
129 	 * The eVMCS flag can be set if the enlightened VMCS capability has
130 	 * been enabled.
131 	 */
132 	set_default_vmx_state(state, state_sz);
133 	state->hdr.vmx.vmxon_pa = -1ull;
134 	state->hdr.vmx.vmcs12_pa = -1ull;
135 	test_nested_state_expect_einval(vcpu, state);
136 
137 	state->flags &= KVM_STATE_NESTED_EVMCS;
138 	if (have_evmcs) {
139 		test_nested_state_expect_einval(vcpu, state);
140 		vcpu_enable_evmcs(vcpu);
141 	}
142 	test_nested_state(vcpu, state);
143 
144 	/* It is invalid to have vmxon_pa == -1ull and SMM flags non-zero. */
145 	state->hdr.vmx.smm.flags = 1;
146 	test_nested_state_expect_einval(vcpu, state);
147 
148 	/* Invalid flags are rejected. */
149 	set_default_vmx_state(state, state_sz);
150 	state->hdr.vmx.flags = ~0;
151 	test_nested_state_expect_einval(vcpu, state);
152 
153 	/* It is invalid to have vmxon_pa == -1ull and vmcs_pa != -1ull. */
154 	set_default_vmx_state(state, state_sz);
155 	state->hdr.vmx.vmxon_pa = -1ull;
156 	state->flags = 0;
157 	test_nested_state_expect_einval(vcpu, state);
158 
159 	/* It is invalid to have vmxon_pa set to a non-page aligned address. */
160 	set_default_vmx_state(state, state_sz);
161 	state->hdr.vmx.vmxon_pa = 1;
162 	test_nested_state_expect_einval(vcpu, state);
163 
164 	/*
165 	 * It is invalid to have KVM_STATE_NESTED_SMM_GUEST_MODE and
166 	 * KVM_STATE_NESTED_GUEST_MODE set together.
167 	 */
168 	set_default_vmx_state(state, state_sz);
169 	state->flags = KVM_STATE_NESTED_GUEST_MODE  |
170 		      KVM_STATE_NESTED_RUN_PENDING;
171 	state->hdr.vmx.smm.flags = KVM_STATE_NESTED_SMM_GUEST_MODE;
172 	test_nested_state_expect_einval(vcpu, state);
173 
174 	/*
175 	 * It is invalid to have any of the SMM flags set besides:
176 	 *	KVM_STATE_NESTED_SMM_GUEST_MODE
177 	 *	KVM_STATE_NESTED_SMM_VMXON
178 	 */
179 	set_default_vmx_state(state, state_sz);
180 	state->hdr.vmx.smm.flags = ~(KVM_STATE_NESTED_SMM_GUEST_MODE |
181 				KVM_STATE_NESTED_SMM_VMXON);
182 	test_nested_state_expect_einval(vcpu, state);
183 
184 	/* Outside SMM, SMM flags must be zero. */
185 	set_default_vmx_state(state, state_sz);
186 	state->flags = 0;
187 	state->hdr.vmx.smm.flags = KVM_STATE_NESTED_SMM_GUEST_MODE;
188 	test_nested_state_expect_einval(vcpu, state);
189 
190 	/*
191 	 * Size must be large enough to fit kvm_nested_state and vmcs12
192 	 * if VMCS12 physical address is set
193 	 */
194 	set_default_vmx_state(state, state_sz);
195 	state->size = sizeof(*state);
196 	state->flags = 0;
197 	test_nested_state_expect_einval(vcpu, state);
198 
199 	set_default_vmx_state(state, state_sz);
200 	state->size = sizeof(*state);
201 	state->flags = 0;
202 	state->hdr.vmx.vmcs12_pa = -1;
203 	test_nested_state(vcpu, state);
204 
205 	/*
206 	 * KVM_SET_NESTED_STATE succeeds with invalid VMCS
207 	 * contents but L2 not running.
208 	 */
209 	set_default_vmx_state(state, state_sz);
210 	state->flags = 0;
211 	test_nested_state(vcpu, state);
212 
213 	/* Invalid flags are rejected, even if no VMCS loaded. */
214 	set_default_vmx_state(state, state_sz);
215 	state->size = sizeof(*state);
216 	state->flags = 0;
217 	state->hdr.vmx.vmcs12_pa = -1;
218 	state->hdr.vmx.flags = ~0;
219 	test_nested_state_expect_einval(vcpu, state);
220 
221 	/* vmxon_pa cannot be the same address as vmcs_pa. */
222 	set_default_vmx_state(state, state_sz);
223 	state->hdr.vmx.vmxon_pa = 0;
224 	state->hdr.vmx.vmcs12_pa = 0;
225 	test_nested_state_expect_einval(vcpu, state);
226 
227 	/*
228 	 * Test that if we leave nesting the state reflects that when we get
229 	 * it again.
230 	 */
231 	set_default_vmx_state(state, state_sz);
232 	state->hdr.vmx.vmxon_pa = -1ull;
233 	state->hdr.vmx.vmcs12_pa = -1ull;
234 	state->flags = 0;
235 	test_nested_state(vcpu, state);
236 	vcpu_nested_state_get(vcpu, state);
237 	TEST_ASSERT(state->size >= sizeof(*state) && state->size <= state_sz,
238 		    "Size must be between %ld and %d.  The size returned was %d.",
239 		    sizeof(*state), state_sz, state->size);
240 	TEST_ASSERT(state->hdr.vmx.vmxon_pa == -1ull, "vmxon_pa must be -1ull.");
241 	TEST_ASSERT(state->hdr.vmx.vmcs12_pa == -1ull, "vmcs_pa must be -1ull.");
242 
243 	free(state);
244 }
245 
246 int main(int argc, char *argv[])
247 {
248 	struct kvm_vm *vm;
249 	struct kvm_nested_state state;
250 	struct kvm_vcpu *vcpu;
251 
252 	have_evmcs = kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS);
253 
254 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_NESTED_STATE));
255 
256 	/*
257 	 * AMD currently does not implement set_nested_state, so for now we
258 	 * just early out.
259 	 */
260 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
261 
262 	vm = vm_create_with_one_vcpu(&vcpu, NULL);
263 
264 	/*
265 	 * First run tests with VMX disabled to check error handling.
266 	 */
267 	vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_VMX);
268 
269 	/* Passing a NULL kvm_nested_state causes a EFAULT. */
270 	test_nested_state_expect_efault(vcpu, NULL);
271 
272 	/* 'size' cannot be smaller than sizeof(kvm_nested_state). */
273 	set_default_state(&state);
274 	state.size = 0;
275 	test_nested_state_expect_einval(vcpu, &state);
276 
277 	/*
278 	 * Setting the flags 0xf fails the flags check.  The only flags that
279 	 * can be used are:
280 	 *     KVM_STATE_NESTED_GUEST_MODE
281 	 *     KVM_STATE_NESTED_RUN_PENDING
282 	 *     KVM_STATE_NESTED_EVMCS
283 	 */
284 	set_default_state(&state);
285 	state.flags = 0xf;
286 	test_nested_state_expect_einval(vcpu, &state);
287 
288 	/*
289 	 * If KVM_STATE_NESTED_RUN_PENDING is set then
290 	 * KVM_STATE_NESTED_GUEST_MODE has to be set as well.
291 	 */
292 	set_default_state(&state);
293 	state.flags = KVM_STATE_NESTED_RUN_PENDING;
294 	test_nested_state_expect_einval(vcpu, &state);
295 
296 	test_vmx_nested_state(vcpu);
297 
298 	kvm_vm_free(vm);
299 	return 0;
300 }
301