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19#include <linux/cpu.h>
20#include <linux/of_irq.h>
21#include <linux/kvm.h>
22#include <linux/kvm_host.h>
23#include <linux/interrupt.h>
24
25#include <clocksource/arm_arch_timer.h>
26#include <asm/arch_timer.h>
27
28#include <kvm/arm_vgic.h>
29#include <kvm/arm_arch_timer.h>
30
31static struct timecounter *timecounter;
32static struct workqueue_struct *wqueue;
33static unsigned int host_vtimer_irq;
34
35static cycle_t kvm_phys_timer_read(void)
36{
37 return timecounter->cc->read(timecounter->cc);
38}
39
40static bool timer_is_armed(struct arch_timer_cpu *timer)
41{
42 return timer->armed;
43}
44
45
46static void timer_arm(struct arch_timer_cpu *timer, u64 ns)
47{
48 timer->armed = true;
49 hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns),
50 HRTIMER_MODE_ABS);
51}
52
53static void timer_disarm(struct arch_timer_cpu *timer)
54{
55 if (timer_is_armed(timer)) {
56 hrtimer_cancel(&timer->timer);
57 cancel_work_sync(&timer->expired);
58 timer->armed = false;
59 }
60}
61
62static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu)
63{
64 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
65
66 timer->cntv_ctl |= ARCH_TIMER_CTRL_IT_MASK;
67 kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
68 timer->irq->irq,
69 timer->irq->level);
70}
71
72static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
73{
74 struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id;
75
76
77
78
79
80
81
82 pr_warn("Unexpected interrupt %d on vcpu %p\n", irq, vcpu);
83 return IRQ_HANDLED;
84}
85
86static void kvm_timer_inject_irq_work(struct work_struct *work)
87{
88 struct kvm_vcpu *vcpu;
89
90 vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired);
91 vcpu->arch.timer_cpu.armed = false;
92 kvm_timer_inject_irq(vcpu);
93}
94
95static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt)
96{
97 struct arch_timer_cpu *timer;
98 timer = container_of(hrt, struct arch_timer_cpu, timer);
99 queue_work(wqueue, &timer->expired);
100 return HRTIMER_NORESTART;
101}
102
103
104
105
106
107
108
109
110void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
111{
112 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
113
114
115
116
117
118
119 timer_disarm(timer);
120}
121
122
123
124
125
126
127
128
129void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
130{
131 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
132 cycle_t cval, now;
133 u64 ns;
134
135 if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) ||
136 !(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE))
137 return;
138
139 cval = timer->cntv_cval;
140 now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
141
142 BUG_ON(timer_is_armed(timer));
143
144 if (cval <= now) {
145
146
147
148
149 kvm_timer_inject_irq(vcpu);
150 return;
151 }
152
153 ns = cyclecounter_cyc2ns(timecounter->cc, cval - now);
154 timer_arm(timer, ns);
155}
156
157void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
158 const struct kvm_irq_level *irq)
159{
160 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
161
162
163
164
165
166
167
168 timer->irq = irq;
169}
170
171void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
172{
173 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
174
175 INIT_WORK(&timer->expired, kvm_timer_inject_irq_work);
176 hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
177 timer->timer.function = kvm_timer_expire;
178}
179
180static void kvm_timer_init_interrupt(void *info)
181{
182 enable_percpu_irq(host_vtimer_irq, 0);
183}
184
185int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
186{
187 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
188
189 switch (regid) {
190 case KVM_REG_ARM_TIMER_CTL:
191 timer->cntv_ctl = value;
192 break;
193 case KVM_REG_ARM_TIMER_CNT:
194 vcpu->kvm->arch.timer.cntvoff = kvm_phys_timer_read() - value;
195 break;
196 case KVM_REG_ARM_TIMER_CVAL:
197 timer->cntv_cval = value;
198 break;
199 default:
200 return -1;
201 }
202 return 0;
203}
204
205u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
206{
207 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
208
209 switch (regid) {
210 case KVM_REG_ARM_TIMER_CTL:
211 return timer->cntv_ctl;
212 case KVM_REG_ARM_TIMER_CNT:
213 return kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
214 case KVM_REG_ARM_TIMER_CVAL:
215 return timer->cntv_cval;
216 }
217 return (u64)-1;
218}
219
220static int kvm_timer_cpu_notify(struct notifier_block *self,
221 unsigned long action, void *cpu)
222{
223 switch (action) {
224 case CPU_STARTING:
225 case CPU_STARTING_FROZEN:
226 kvm_timer_init_interrupt(NULL);
227 break;
228 case CPU_DYING:
229 case CPU_DYING_FROZEN:
230 disable_percpu_irq(host_vtimer_irq);
231 break;
232 }
233
234 return NOTIFY_OK;
235}
236
237static struct notifier_block kvm_timer_cpu_nb = {
238 .notifier_call = kvm_timer_cpu_notify,
239};
240
241static const struct of_device_id arch_timer_of_match[] = {
242 { .compatible = "arm,armv7-timer", },
243 { .compatible = "arm,armv8-timer", },
244 {},
245};
246
247int kvm_timer_hyp_init(void)
248{
249 struct device_node *np;
250 unsigned int ppi;
251 int err;
252
253 timecounter = arch_timer_get_timecounter();
254 if (!timecounter)
255 return -ENODEV;
256
257 np = of_find_matching_node(NULL, arch_timer_of_match);
258 if (!np) {
259 kvm_err("kvm_arch_timer: can't find DT node\n");
260 return -ENODEV;
261 }
262
263 ppi = irq_of_parse_and_map(np, 2);
264 if (!ppi) {
265 kvm_err("kvm_arch_timer: no virtual timer interrupt\n");
266 err = -EINVAL;
267 goto out;
268 }
269
270 err = request_percpu_irq(ppi, kvm_arch_timer_handler,
271 "kvm guest timer", kvm_get_running_vcpus());
272 if (err) {
273 kvm_err("kvm_arch_timer: can't request interrupt %d (%d)\n",
274 ppi, err);
275 goto out;
276 }
277
278 host_vtimer_irq = ppi;
279
280 err = __register_cpu_notifier(&kvm_timer_cpu_nb);
281 if (err) {
282 kvm_err("Cannot register timer CPU notifier\n");
283 goto out_free;
284 }
285
286 wqueue = create_singlethread_workqueue("kvm_arch_timer");
287 if (!wqueue) {
288 err = -ENOMEM;
289 goto out_free;
290 }
291
292 kvm_info("%s IRQ%d\n", np->name, ppi);
293 on_each_cpu(kvm_timer_init_interrupt, NULL, 1);
294
295 goto out;
296out_free:
297 free_percpu_irq(ppi, kvm_get_running_vcpus());
298out:
299 of_node_put(np);
300 return err;
301}
302
303void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
304{
305 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
306
307 timer_disarm(timer);
308}
309
310int kvm_timer_init(struct kvm *kvm)
311{
312 if (timecounter && wqueue) {
313 kvm->arch.timer.cntvoff = kvm_phys_timer_read();
314 kvm->arch.timer.enabled = 1;
315 }
316
317 return 0;
318}
319