xref: /linux/tools/testing/selftests/kvm/aarch64/psci_test.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * psci_test - Tests relating to KVM's PSCI implementation.
4  *
5  * Copyright (c) 2021 Google LLC.
6  *
7  * This test includes:
8  *  - A regression test for a race between KVM servicing the PSCI CPU_ON call
9  *    and userspace reading the targeted vCPU's registers.
10  *  - A test for KVM's handling of PSCI SYSTEM_SUSPEND and the associated
11  *    KVM_SYSTEM_EVENT_SUSPEND UAPI.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/psci.h>
16 #include <asm/cputype.h>
17 
18 #include "kvm_util.h"
19 #include "processor.h"
20 #include "test_util.h"
21 
22 #define CPU_ON_ENTRY_ADDR 0xfeedf00dul
23 #define CPU_ON_CONTEXT_ID 0xdeadc0deul
24 
25 static uint64_t psci_cpu_on(uint64_t target_cpu, uint64_t entry_addr,
26 			    uint64_t context_id)
27 {
28 	struct arm_smccc_res res;
29 
30 	smccc_hvc(PSCI_0_2_FN64_CPU_ON, target_cpu, entry_addr, context_id,
31 		  0, 0, 0, 0, &res);
32 
33 	return res.a0;
34 }
35 
36 static uint64_t psci_affinity_info(uint64_t target_affinity,
37 				   uint64_t lowest_affinity_level)
38 {
39 	struct arm_smccc_res res;
40 
41 	smccc_hvc(PSCI_0_2_FN64_AFFINITY_INFO, target_affinity, lowest_affinity_level,
42 		  0, 0, 0, 0, 0, &res);
43 
44 	return res.a0;
45 }
46 
47 static uint64_t psci_system_suspend(uint64_t entry_addr, uint64_t context_id)
48 {
49 	struct arm_smccc_res res;
50 
51 	smccc_hvc(PSCI_1_0_FN64_SYSTEM_SUSPEND, entry_addr, context_id,
52 		  0, 0, 0, 0, 0, &res);
53 
54 	return res.a0;
55 }
56 
57 static uint64_t psci_system_off2(uint64_t type, uint64_t cookie)
58 {
59 	struct arm_smccc_res res;
60 
61 	smccc_hvc(PSCI_1_3_FN64_SYSTEM_OFF2, type, cookie, 0, 0, 0, 0, 0, &res);
62 
63 	return res.a0;
64 }
65 
66 static uint64_t psci_features(uint32_t func_id)
67 {
68 	struct arm_smccc_res res;
69 
70 	smccc_hvc(PSCI_1_0_FN_PSCI_FEATURES, func_id, 0, 0, 0, 0, 0, 0, &res);
71 
72 	return res.a0;
73 }
74 
75 static void vcpu_power_off(struct kvm_vcpu *vcpu)
76 {
77 	struct kvm_mp_state mp_state = {
78 		.mp_state = KVM_MP_STATE_STOPPED,
79 	};
80 
81 	vcpu_mp_state_set(vcpu, &mp_state);
82 }
83 
84 static struct kvm_vm *setup_vm(void *guest_code, struct kvm_vcpu **source,
85 			       struct kvm_vcpu **target)
86 {
87 	struct kvm_vcpu_init init;
88 	struct kvm_vm *vm;
89 
90 	vm = vm_create(2);
91 
92 	vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init);
93 	init.features[0] |= (1 << KVM_ARM_VCPU_PSCI_0_2);
94 
95 	*source = aarch64_vcpu_add(vm, 0, &init, guest_code);
96 	*target = aarch64_vcpu_add(vm, 1, &init, guest_code);
97 
98 	return vm;
99 }
100 
101 static void enter_guest(struct kvm_vcpu *vcpu)
102 {
103 	struct ucall uc;
104 
105 	vcpu_run(vcpu);
106 	if (get_ucall(vcpu, &uc) == UCALL_ABORT)
107 		REPORT_GUEST_ASSERT(uc);
108 }
109 
110 static void assert_vcpu_reset(struct kvm_vcpu *vcpu)
111 {
112 	uint64_t obs_pc, obs_x0;
113 
114 	vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.pc), &obs_pc);
115 	vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.regs[0]), &obs_x0);
116 
117 	TEST_ASSERT(obs_pc == CPU_ON_ENTRY_ADDR,
118 		    "unexpected target cpu pc: %lx (expected: %lx)",
119 		    obs_pc, CPU_ON_ENTRY_ADDR);
120 	TEST_ASSERT(obs_x0 == CPU_ON_CONTEXT_ID,
121 		    "unexpected target context id: %lx (expected: %lx)",
122 		    obs_x0, CPU_ON_CONTEXT_ID);
123 }
124 
125 static void guest_test_cpu_on(uint64_t target_cpu)
126 {
127 	uint64_t target_state;
128 
129 	GUEST_ASSERT(!psci_cpu_on(target_cpu, CPU_ON_ENTRY_ADDR, CPU_ON_CONTEXT_ID));
130 
131 	do {
132 		target_state = psci_affinity_info(target_cpu, 0);
133 
134 		GUEST_ASSERT((target_state == PSCI_0_2_AFFINITY_LEVEL_ON) ||
135 			     (target_state == PSCI_0_2_AFFINITY_LEVEL_OFF));
136 	} while (target_state != PSCI_0_2_AFFINITY_LEVEL_ON);
137 
138 	GUEST_DONE();
139 }
140 
141 static void host_test_cpu_on(void)
142 {
143 	struct kvm_vcpu *source, *target;
144 	uint64_t target_mpidr;
145 	struct kvm_vm *vm;
146 	struct ucall uc;
147 
148 	vm = setup_vm(guest_test_cpu_on, &source, &target);
149 
150 	/*
151 	 * make sure the target is already off when executing the test.
152 	 */
153 	vcpu_power_off(target);
154 
155 	vcpu_get_reg(target, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), &target_mpidr);
156 	vcpu_args_set(source, 1, target_mpidr & MPIDR_HWID_BITMASK);
157 	enter_guest(source);
158 
159 	if (get_ucall(source, &uc) != UCALL_DONE)
160 		TEST_FAIL("Unhandled ucall: %lu", uc.cmd);
161 
162 	assert_vcpu_reset(target);
163 	kvm_vm_free(vm);
164 }
165 
166 static void guest_test_system_suspend(void)
167 {
168 	uint64_t ret;
169 
170 	/* assert that SYSTEM_SUSPEND is discoverable */
171 	GUEST_ASSERT(!psci_features(PSCI_1_0_FN_SYSTEM_SUSPEND));
172 	GUEST_ASSERT(!psci_features(PSCI_1_0_FN64_SYSTEM_SUSPEND));
173 
174 	ret = psci_system_suspend(CPU_ON_ENTRY_ADDR, CPU_ON_CONTEXT_ID);
175 	GUEST_SYNC(ret);
176 }
177 
178 static void host_test_system_suspend(void)
179 {
180 	struct kvm_vcpu *source, *target;
181 	struct kvm_run *run;
182 	struct kvm_vm *vm;
183 
184 	vm = setup_vm(guest_test_system_suspend, &source, &target);
185 	vm_enable_cap(vm, KVM_CAP_ARM_SYSTEM_SUSPEND, 0);
186 
187 	vcpu_power_off(target);
188 	run = source->run;
189 
190 	enter_guest(source);
191 
192 	TEST_ASSERT_KVM_EXIT_REASON(source, KVM_EXIT_SYSTEM_EVENT);
193 	TEST_ASSERT(run->system_event.type == KVM_SYSTEM_EVENT_SUSPEND,
194 		    "Unhandled system event: %u (expected: %u)",
195 		    run->system_event.type, KVM_SYSTEM_EVENT_SUSPEND);
196 
197 	kvm_vm_free(vm);
198 }
199 
200 static void guest_test_system_off2(void)
201 {
202 	uint64_t ret;
203 
204 	/* assert that SYSTEM_OFF2 is discoverable */
205 	GUEST_ASSERT(psci_features(PSCI_1_3_FN_SYSTEM_OFF2) &
206 		     PSCI_1_3_OFF_TYPE_HIBERNATE_OFF);
207 	GUEST_ASSERT(psci_features(PSCI_1_3_FN64_SYSTEM_OFF2) &
208 		     PSCI_1_3_OFF_TYPE_HIBERNATE_OFF);
209 
210 	/* With non-zero 'cookie' field, it should fail */
211 	ret = psci_system_off2(PSCI_1_3_OFF_TYPE_HIBERNATE_OFF, 1);
212 	GUEST_ASSERT(ret == PSCI_RET_INVALID_PARAMS);
213 
214 	/*
215 	 * This would normally never return, so KVM sets the return value
216 	 * to PSCI_RET_INTERNAL_FAILURE. The test case *does* return, so
217 	 * that it can test both values for HIBERNATE_OFF.
218 	 */
219 	ret = psci_system_off2(PSCI_1_3_OFF_TYPE_HIBERNATE_OFF, 0);
220 	GUEST_ASSERT(ret == PSCI_RET_INTERNAL_FAILURE);
221 
222 	/*
223 	 * Revision F.b of the PSCI v1.3 specification documents zero as an
224 	 * alias for HIBERNATE_OFF, since that's the value used in earlier
225 	 * revisions of the spec and some implementations in the field.
226 	 */
227 	ret = psci_system_off2(0, 1);
228 	GUEST_ASSERT(ret == PSCI_RET_INVALID_PARAMS);
229 
230 	ret = psci_system_off2(0, 0);
231 	GUEST_ASSERT(ret == PSCI_RET_INTERNAL_FAILURE);
232 
233 	GUEST_DONE();
234 }
235 
236 static void host_test_system_off2(void)
237 {
238 	struct kvm_vcpu *source, *target;
239 	struct kvm_mp_state mps;
240 	uint64_t psci_version = 0;
241 	int nr_shutdowns = 0;
242 	struct kvm_run *run;
243 	struct ucall uc;
244 
245 	setup_vm(guest_test_system_off2, &source, &target);
246 
247 	vcpu_get_reg(target, KVM_REG_ARM_PSCI_VERSION, &psci_version);
248 
249 	TEST_ASSERT(psci_version >= PSCI_VERSION(1, 3),
250 		    "Unexpected PSCI version %lu.%lu",
251 		    PSCI_VERSION_MAJOR(psci_version),
252 		    PSCI_VERSION_MINOR(psci_version));
253 
254 	vcpu_power_off(target);
255 	run = source->run;
256 
257 	enter_guest(source);
258 	while (run->exit_reason == KVM_EXIT_SYSTEM_EVENT) {
259 		TEST_ASSERT(run->system_event.type == KVM_SYSTEM_EVENT_SHUTDOWN,
260 			    "Unhandled system event: %u (expected: %u)",
261 			    run->system_event.type, KVM_SYSTEM_EVENT_SHUTDOWN);
262 		TEST_ASSERT(run->system_event.ndata >= 1,
263 			    "Unexpected amount of system event data: %u (expected, >= 1)",
264 			    run->system_event.ndata);
265 		TEST_ASSERT(run->system_event.data[0] & KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2,
266 			    "PSCI_OFF2 flag not set. Flags %llu (expected %llu)",
267 			    run->system_event.data[0], KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2);
268 
269 		nr_shutdowns++;
270 
271 		/* Restart the vCPU */
272 	        mps.mp_state = KVM_MP_STATE_RUNNABLE;
273 		vcpu_mp_state_set(source, &mps);
274 
275 		enter_guest(source);
276 	}
277 
278 	TEST_ASSERT(get_ucall(source, &uc) == UCALL_DONE, "Guest did not exit cleanly");
279 	TEST_ASSERT(nr_shutdowns == 2, "Two shutdown events were expected, but saw %d", nr_shutdowns);
280 }
281 
282 int main(void)
283 {
284 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_SYSTEM_SUSPEND));
285 
286 	host_test_cpu_on();
287 	host_test_system_suspend();
288 	host_test_system_off2();
289 	return 0;
290 }
291