xref: /linux/tools/testing/selftests/kvm/arm64/psci_test.c (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
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 	do_smccc(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 	do_smccc(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 	do_smccc(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 	do_smccc(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 	do_smccc(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 	kvm_get_default_vcpu_target(vm, &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 	kvm_arch_vm_finalize_vcpus(vm);
99 	return vm;
100 }
101 
102 static void enter_guest(struct kvm_vcpu *vcpu)
103 {
104 	struct ucall uc;
105 
106 	vcpu_run(vcpu);
107 	if (get_ucall(vcpu, &uc) == UCALL_ABORT)
108 		REPORT_GUEST_ASSERT(uc);
109 }
110 
111 static void assert_vcpu_reset(struct kvm_vcpu *vcpu)
112 {
113 	uint64_t obs_pc, obs_x0;
114 
115 	obs_pc = vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.pc));
116 	obs_x0 = vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.regs[0]));
117 
118 	TEST_ASSERT(obs_pc == CPU_ON_ENTRY_ADDR,
119 		    "unexpected target cpu pc: %lx (expected: %lx)",
120 		    obs_pc, CPU_ON_ENTRY_ADDR);
121 	TEST_ASSERT(obs_x0 == CPU_ON_CONTEXT_ID,
122 		    "unexpected target context id: %lx (expected: %lx)",
123 		    obs_x0, CPU_ON_CONTEXT_ID);
124 }
125 
126 static void guest_test_cpu_on(uint64_t target_cpu)
127 {
128 	uint64_t target_state;
129 
130 	GUEST_ASSERT(!psci_cpu_on(target_cpu, CPU_ON_ENTRY_ADDR, CPU_ON_CONTEXT_ID));
131 
132 	do {
133 		target_state = psci_affinity_info(target_cpu, 0);
134 
135 		GUEST_ASSERT((target_state == PSCI_0_2_AFFINITY_LEVEL_ON) ||
136 			     (target_state == PSCI_0_2_AFFINITY_LEVEL_OFF));
137 	} while (target_state != PSCI_0_2_AFFINITY_LEVEL_ON);
138 
139 	GUEST_DONE();
140 }
141 
142 static void host_test_cpu_on(void)
143 {
144 	struct kvm_vcpu *source, *target;
145 	uint64_t target_mpidr;
146 	struct kvm_vm *vm;
147 	struct ucall uc;
148 
149 	vm = setup_vm(guest_test_cpu_on, &source, &target);
150 
151 	/*
152 	 * make sure the target is already off when executing the test.
153 	 */
154 	vcpu_power_off(target);
155 
156 	target_mpidr = vcpu_get_reg(target, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1));
157 	vcpu_args_set(source, 1, target_mpidr & MPIDR_HWID_BITMASK);
158 	enter_guest(source);
159 
160 	if (get_ucall(source, &uc) != UCALL_DONE)
161 		TEST_FAIL("Unhandled ucall: %lu", uc.cmd);
162 
163 	assert_vcpu_reset(target);
164 	kvm_vm_free(vm);
165 }
166 
167 static void guest_test_system_suspend(void)
168 {
169 	uint64_t ret;
170 
171 	/* assert that SYSTEM_SUSPEND is discoverable */
172 	GUEST_ASSERT(!psci_features(PSCI_1_0_FN_SYSTEM_SUSPEND));
173 	GUEST_ASSERT(!psci_features(PSCI_1_0_FN64_SYSTEM_SUSPEND));
174 
175 	ret = psci_system_suspend(CPU_ON_ENTRY_ADDR, CPU_ON_CONTEXT_ID);
176 	GUEST_SYNC(ret);
177 }
178 
179 static void host_test_system_suspend(void)
180 {
181 	struct kvm_vcpu *source, *target;
182 	struct kvm_run *run;
183 	struct kvm_vm *vm;
184 
185 	vm = setup_vm(guest_test_system_suspend, &source, &target);
186 	vm_enable_cap(vm, KVM_CAP_ARM_SYSTEM_SUSPEND, 0);
187 
188 	vcpu_power_off(target);
189 	run = source->run;
190 
191 	enter_guest(source);
192 
193 	TEST_ASSERT_KVM_EXIT_REASON(source, KVM_EXIT_SYSTEM_EVENT);
194 	TEST_ASSERT(run->system_event.type == KVM_SYSTEM_EVENT_SUSPEND,
195 		    "Unhandled system event: %u (expected: %u)",
196 		    run->system_event.type, KVM_SYSTEM_EVENT_SUSPEND);
197 
198 	kvm_vm_free(vm);
199 }
200 
201 static void guest_test_system_off2(void)
202 {
203 	uint64_t ret;
204 
205 	/* assert that SYSTEM_OFF2 is discoverable */
206 	GUEST_ASSERT(psci_features(PSCI_1_3_FN_SYSTEM_OFF2) &
207 		     PSCI_1_3_OFF_TYPE_HIBERNATE_OFF);
208 	GUEST_ASSERT(psci_features(PSCI_1_3_FN64_SYSTEM_OFF2) &
209 		     PSCI_1_3_OFF_TYPE_HIBERNATE_OFF);
210 
211 	/* With non-zero 'cookie' field, it should fail */
212 	ret = psci_system_off2(PSCI_1_3_OFF_TYPE_HIBERNATE_OFF, 1);
213 	GUEST_ASSERT(ret == PSCI_RET_INVALID_PARAMS);
214 
215 	/*
216 	 * This would normally never return, so KVM sets the return value
217 	 * to PSCI_RET_INTERNAL_FAILURE. The test case *does* return, so
218 	 * that it can test both values for HIBERNATE_OFF.
219 	 */
220 	ret = psci_system_off2(PSCI_1_3_OFF_TYPE_HIBERNATE_OFF, 0);
221 	GUEST_ASSERT(ret == PSCI_RET_INTERNAL_FAILURE);
222 
223 	/*
224 	 * Revision F.b of the PSCI v1.3 specification documents zero as an
225 	 * alias for HIBERNATE_OFF, since that's the value used in earlier
226 	 * revisions of the spec and some implementations in the field.
227 	 */
228 	ret = psci_system_off2(0, 1);
229 	GUEST_ASSERT(ret == PSCI_RET_INVALID_PARAMS);
230 
231 	ret = psci_system_off2(0, 0);
232 	GUEST_ASSERT(ret == PSCI_RET_INTERNAL_FAILURE);
233 
234 	GUEST_DONE();
235 }
236 
237 static void host_test_system_off2(void)
238 {
239 	struct kvm_vcpu *source, *target;
240 	struct kvm_mp_state mps;
241 	uint64_t psci_version = 0;
242 	int nr_shutdowns = 0;
243 	struct kvm_run *run;
244 	struct ucall uc;
245 
246 	setup_vm(guest_test_system_off2, &source, &target);
247 
248 	psci_version = vcpu_get_reg(target, KVM_REG_ARM_PSCI_VERSION);
249 
250 	TEST_ASSERT(psci_version >= PSCI_VERSION(1, 3),
251 		    "Unexpected PSCI version %lu.%lu",
252 		    PSCI_VERSION_MAJOR(psci_version),
253 		    PSCI_VERSION_MINOR(psci_version));
254 
255 	vcpu_power_off(target);
256 	run = source->run;
257 
258 	enter_guest(source);
259 	while (run->exit_reason == KVM_EXIT_SYSTEM_EVENT) {
260 		TEST_ASSERT(run->system_event.type == KVM_SYSTEM_EVENT_SHUTDOWN,
261 			    "Unhandled system event: %u (expected: %u)",
262 			    run->system_event.type, KVM_SYSTEM_EVENT_SHUTDOWN);
263 		TEST_ASSERT(run->system_event.ndata >= 1,
264 			    "Unexpected amount of system event data: %u (expected, >= 1)",
265 			    run->system_event.ndata);
266 		TEST_ASSERT(run->system_event.data[0] & KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2,
267 			    "PSCI_OFF2 flag not set. Flags %llu (expected %llu)",
268 			    run->system_event.data[0], KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2);
269 
270 		nr_shutdowns++;
271 
272 		/* Restart the vCPU */
273 	        mps.mp_state = KVM_MP_STATE_RUNNABLE;
274 		vcpu_mp_state_set(source, &mps);
275 
276 		enter_guest(source);
277 	}
278 
279 	TEST_ASSERT(get_ucall(source, &uc) == UCALL_DONE, "Guest did not exit cleanly");
280 	TEST_ASSERT(nr_shutdowns == 2, "Two shutdown events were expected, but saw %d", nr_shutdowns);
281 }
282 
283 int main(void)
284 {
285 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_SYSTEM_SUSPEND));
286 
287 	host_test_cpu_on();
288 	host_test_system_suspend();
289 	host_test_system_off2();
290 	return 0;
291 }
292