xref: /linux/tools/testing/selftests/kvm/aarch64/arch_timer.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * The test validates both the virtual and physical timer IRQs using
4  * CVAL and TVAL registers.
5  *
6  * Copyright (c) 2021, Google LLC.
7  */
8 #include "arch_timer.h"
9 #include "delay.h"
10 #include "gic.h"
11 #include "processor.h"
12 #include "timer_test.h"
13 #include "ucall_common.h"
14 #include "vgic.h"
15 
16 enum guest_stage {
17 	GUEST_STAGE_VTIMER_CVAL = 1,
18 	GUEST_STAGE_VTIMER_TVAL,
19 	GUEST_STAGE_PTIMER_CVAL,
20 	GUEST_STAGE_PTIMER_TVAL,
21 	GUEST_STAGE_MAX,
22 };
23 
24 static int vtimer_irq, ptimer_irq;
25 
26 static void
27 guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
28 {
29 	switch (shared_data->guest_stage) {
30 	case GUEST_STAGE_VTIMER_CVAL:
31 		timer_set_next_cval_ms(VIRTUAL, test_args.timer_period_ms);
32 		shared_data->xcnt = timer_get_cntct(VIRTUAL);
33 		timer_set_ctl(VIRTUAL, CTL_ENABLE);
34 		break;
35 	case GUEST_STAGE_VTIMER_TVAL:
36 		timer_set_next_tval_ms(VIRTUAL, test_args.timer_period_ms);
37 		shared_data->xcnt = timer_get_cntct(VIRTUAL);
38 		timer_set_ctl(VIRTUAL, CTL_ENABLE);
39 		break;
40 	case GUEST_STAGE_PTIMER_CVAL:
41 		timer_set_next_cval_ms(PHYSICAL, test_args.timer_period_ms);
42 		shared_data->xcnt = timer_get_cntct(PHYSICAL);
43 		timer_set_ctl(PHYSICAL, CTL_ENABLE);
44 		break;
45 	case GUEST_STAGE_PTIMER_TVAL:
46 		timer_set_next_tval_ms(PHYSICAL, test_args.timer_period_ms);
47 		shared_data->xcnt = timer_get_cntct(PHYSICAL);
48 		timer_set_ctl(PHYSICAL, CTL_ENABLE);
49 		break;
50 	default:
51 		GUEST_ASSERT(0);
52 	}
53 }
54 
55 static void guest_validate_irq(unsigned int intid,
56 				struct test_vcpu_shared_data *shared_data)
57 {
58 	enum guest_stage stage = shared_data->guest_stage;
59 	uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
60 	unsigned long xctl = 0;
61 	unsigned int timer_irq = 0;
62 	unsigned int accessor;
63 
64 	if (intid == IAR_SPURIOUS)
65 		return;
66 
67 	switch (stage) {
68 	case GUEST_STAGE_VTIMER_CVAL:
69 	case GUEST_STAGE_VTIMER_TVAL:
70 		accessor = VIRTUAL;
71 		timer_irq = vtimer_irq;
72 		break;
73 	case GUEST_STAGE_PTIMER_CVAL:
74 	case GUEST_STAGE_PTIMER_TVAL:
75 		accessor = PHYSICAL;
76 		timer_irq = ptimer_irq;
77 		break;
78 	default:
79 		GUEST_ASSERT(0);
80 		return;
81 	}
82 
83 	xctl = timer_get_ctl(accessor);
84 	if ((xctl & CTL_IMASK) || !(xctl & CTL_ENABLE))
85 		return;
86 
87 	timer_set_ctl(accessor, CTL_IMASK);
88 	xcnt = timer_get_cntct(accessor);
89 	cval = timer_get_cval(accessor);
90 
91 	xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
92 
93 	/* Make sure we are dealing with the correct timer IRQ */
94 	GUEST_ASSERT_EQ(intid, timer_irq);
95 
96 	/* Basic 'timer condition met' check */
97 	__GUEST_ASSERT(xcnt >= cval,
98 		       "xcnt = 0x%lx, cval = 0x%lx, xcnt_diff_us = 0x%lx",
99 		       xcnt, cval, xcnt_diff_us);
100 	__GUEST_ASSERT(xctl & CTL_ISTATUS, "xctl = 0x%lx", xctl);
101 
102 	WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
103 }
104 
105 static void guest_irq_handler(struct ex_regs *regs)
106 {
107 	unsigned int intid = gic_get_and_ack_irq();
108 	uint32_t cpu = guest_get_vcpuid();
109 	struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
110 
111 	guest_validate_irq(intid, shared_data);
112 
113 	gic_set_eoi(intid);
114 }
115 
116 static void guest_run_stage(struct test_vcpu_shared_data *shared_data,
117 				enum guest_stage stage)
118 {
119 	uint32_t irq_iter, config_iter;
120 
121 	shared_data->guest_stage = stage;
122 	shared_data->nr_iter = 0;
123 
124 	for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
125 		/* Setup the next interrupt */
126 		guest_configure_timer_action(shared_data);
127 
128 		/* Setup a timeout for the interrupt to arrive */
129 		udelay(msecs_to_usecs(test_args.timer_period_ms) +
130 			test_args.timer_err_margin_us);
131 
132 		irq_iter = READ_ONCE(shared_data->nr_iter);
133 		__GUEST_ASSERT(config_iter + 1 == irq_iter,
134 				"config_iter + 1 = 0x%x, irq_iter = 0x%x.\n"
135 				"  Guest timer interrupt was not triggered within the specified\n"
136 				"  interval, try to increase the error margin by [-e] option.\n",
137 				config_iter + 1, irq_iter);
138 	}
139 }
140 
141 static void guest_code(void)
142 {
143 	uint32_t cpu = guest_get_vcpuid();
144 	struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
145 
146 	local_irq_disable();
147 
148 	gic_init(GIC_V3, test_args.nr_vcpus);
149 
150 	timer_set_ctl(VIRTUAL, CTL_IMASK);
151 	timer_set_ctl(PHYSICAL, CTL_IMASK);
152 
153 	gic_irq_enable(vtimer_irq);
154 	gic_irq_enable(ptimer_irq);
155 	local_irq_enable();
156 
157 	guest_run_stage(shared_data, GUEST_STAGE_VTIMER_CVAL);
158 	guest_run_stage(shared_data, GUEST_STAGE_VTIMER_TVAL);
159 	guest_run_stage(shared_data, GUEST_STAGE_PTIMER_CVAL);
160 	guest_run_stage(shared_data, GUEST_STAGE_PTIMER_TVAL);
161 
162 	GUEST_DONE();
163 }
164 
165 static void test_init_timer_irq(struct kvm_vm *vm)
166 {
167 	/* Timer initid should be same for all the vCPUs, so query only vCPU-0 */
168 	vcpu_device_attr_get(vcpus[0], KVM_ARM_VCPU_TIMER_CTRL,
169 			     KVM_ARM_VCPU_TIMER_IRQ_PTIMER, &ptimer_irq);
170 	vcpu_device_attr_get(vcpus[0], KVM_ARM_VCPU_TIMER_CTRL,
171 			     KVM_ARM_VCPU_TIMER_IRQ_VTIMER, &vtimer_irq);
172 
173 	sync_global_to_guest(vm, ptimer_irq);
174 	sync_global_to_guest(vm, vtimer_irq);
175 
176 	pr_debug("ptimer_irq: %d; vtimer_irq: %d\n", ptimer_irq, vtimer_irq);
177 }
178 
179 static int gic_fd;
180 
181 struct kvm_vm *test_vm_create(void)
182 {
183 	struct kvm_vm *vm;
184 	unsigned int i;
185 	int nr_vcpus = test_args.nr_vcpus;
186 
187 	vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
188 
189 	vm_init_descriptor_tables(vm);
190 	vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
191 
192 	if (!test_args.reserved) {
193 		if (kvm_has_cap(KVM_CAP_COUNTER_OFFSET)) {
194 			struct kvm_arm_counter_offset offset = {
195 				.counter_offset = test_args.counter_offset,
196 				.reserved = 0,
197 			};
198 			vm_ioctl(vm, KVM_ARM_SET_COUNTER_OFFSET, &offset);
199 		} else
200 			TEST_FAIL("no support for global offset");
201 	}
202 
203 	for (i = 0; i < nr_vcpus; i++)
204 		vcpu_init_descriptor_tables(vcpus[i]);
205 
206 	test_init_timer_irq(vm);
207 	gic_fd = vgic_v3_setup(vm, nr_vcpus, 64);
208 	__TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3");
209 
210 	/* Make all the test's cmdline args visible to the guest */
211 	sync_global_to_guest(vm, test_args);
212 
213 	return vm;
214 }
215 
216 void test_vm_cleanup(struct kvm_vm *vm)
217 {
218 	close(gic_fd);
219 	kvm_vm_free(vm);
220 }
221