xref: /linux/arch/arm64/kvm/arch_timer.c (revision 3f0a50f345f78183f6e9b39c2f45ca5dcaa511ca)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  * Author: Marc Zyngier <marc.zyngier@arm.com>
5  */
6 
7 #include <linux/cpu.h>
8 #include <linux/kvm.h>
9 #include <linux/kvm_host.h>
10 #include <linux/interrupt.h>
11 #include <linux/irq.h>
12 #include <linux/irqdomain.h>
13 #include <linux/uaccess.h>
14 
15 #include <clocksource/arm_arch_timer.h>
16 #include <asm/arch_timer.h>
17 #include <asm/kvm_emulate.h>
18 #include <asm/kvm_hyp.h>
19 
20 #include <kvm/arm_vgic.h>
21 #include <kvm/arm_arch_timer.h>
22 
23 #include "trace.h"
24 
25 static struct timecounter *timecounter;
26 static unsigned int host_vtimer_irq;
27 static unsigned int host_ptimer_irq;
28 static u32 host_vtimer_irq_flags;
29 static u32 host_ptimer_irq_flags;
30 
31 static DEFINE_STATIC_KEY_FALSE(has_gic_active_state);
32 
33 static const struct kvm_irq_level default_ptimer_irq = {
34 	.irq	= 30,
35 	.level	= 1,
36 };
37 
38 static const struct kvm_irq_level default_vtimer_irq = {
39 	.irq	= 27,
40 	.level	= 1,
41 };
42 
43 static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx);
44 static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
45 				 struct arch_timer_context *timer_ctx);
46 static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx);
47 static void kvm_arm_timer_write(struct kvm_vcpu *vcpu,
48 				struct arch_timer_context *timer,
49 				enum kvm_arch_timer_regs treg,
50 				u64 val);
51 static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
52 			      struct arch_timer_context *timer,
53 			      enum kvm_arch_timer_regs treg);
54 
55 u32 timer_get_ctl(struct arch_timer_context *ctxt)
56 {
57 	struct kvm_vcpu *vcpu = ctxt->vcpu;
58 
59 	switch(arch_timer_ctx_index(ctxt)) {
60 	case TIMER_VTIMER:
61 		return __vcpu_sys_reg(vcpu, CNTV_CTL_EL0);
62 	case TIMER_PTIMER:
63 		return __vcpu_sys_reg(vcpu, CNTP_CTL_EL0);
64 	default:
65 		WARN_ON(1);
66 		return 0;
67 	}
68 }
69 
70 u64 timer_get_cval(struct arch_timer_context *ctxt)
71 {
72 	struct kvm_vcpu *vcpu = ctxt->vcpu;
73 
74 	switch(arch_timer_ctx_index(ctxt)) {
75 	case TIMER_VTIMER:
76 		return __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0);
77 	case TIMER_PTIMER:
78 		return __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);
79 	default:
80 		WARN_ON(1);
81 		return 0;
82 	}
83 }
84 
85 static u64 timer_get_offset(struct arch_timer_context *ctxt)
86 {
87 	struct kvm_vcpu *vcpu = ctxt->vcpu;
88 
89 	switch(arch_timer_ctx_index(ctxt)) {
90 	case TIMER_VTIMER:
91 		return __vcpu_sys_reg(vcpu, CNTVOFF_EL2);
92 	default:
93 		return 0;
94 	}
95 }
96 
97 static void timer_set_ctl(struct arch_timer_context *ctxt, u32 ctl)
98 {
99 	struct kvm_vcpu *vcpu = ctxt->vcpu;
100 
101 	switch(arch_timer_ctx_index(ctxt)) {
102 	case TIMER_VTIMER:
103 		__vcpu_sys_reg(vcpu, CNTV_CTL_EL0) = ctl;
104 		break;
105 	case TIMER_PTIMER:
106 		__vcpu_sys_reg(vcpu, CNTP_CTL_EL0) = ctl;
107 		break;
108 	default:
109 		WARN_ON(1);
110 	}
111 }
112 
113 static void timer_set_cval(struct arch_timer_context *ctxt, u64 cval)
114 {
115 	struct kvm_vcpu *vcpu = ctxt->vcpu;
116 
117 	switch(arch_timer_ctx_index(ctxt)) {
118 	case TIMER_VTIMER:
119 		__vcpu_sys_reg(vcpu, CNTV_CVAL_EL0) = cval;
120 		break;
121 	case TIMER_PTIMER:
122 		__vcpu_sys_reg(vcpu, CNTP_CVAL_EL0) = cval;
123 		break;
124 	default:
125 		WARN_ON(1);
126 	}
127 }
128 
129 static void timer_set_offset(struct arch_timer_context *ctxt, u64 offset)
130 {
131 	struct kvm_vcpu *vcpu = ctxt->vcpu;
132 
133 	switch(arch_timer_ctx_index(ctxt)) {
134 	case TIMER_VTIMER:
135 		__vcpu_sys_reg(vcpu, CNTVOFF_EL2) = offset;
136 		break;
137 	default:
138 		WARN(offset, "timer %ld\n", arch_timer_ctx_index(ctxt));
139 	}
140 }
141 
142 u64 kvm_phys_timer_read(void)
143 {
144 	return timecounter->cc->read(timecounter->cc);
145 }
146 
147 static void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map)
148 {
149 	if (has_vhe()) {
150 		map->direct_vtimer = vcpu_vtimer(vcpu);
151 		map->direct_ptimer = vcpu_ptimer(vcpu);
152 		map->emul_ptimer = NULL;
153 	} else {
154 		map->direct_vtimer = vcpu_vtimer(vcpu);
155 		map->direct_ptimer = NULL;
156 		map->emul_ptimer = vcpu_ptimer(vcpu);
157 	}
158 
159 	trace_kvm_get_timer_map(vcpu->vcpu_id, map);
160 }
161 
162 static inline bool userspace_irqchip(struct kvm *kvm)
163 {
164 	return static_branch_unlikely(&userspace_irqchip_in_use) &&
165 		unlikely(!irqchip_in_kernel(kvm));
166 }
167 
168 static void soft_timer_start(struct hrtimer *hrt, u64 ns)
169 {
170 	hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns),
171 		      HRTIMER_MODE_ABS_HARD);
172 }
173 
174 static void soft_timer_cancel(struct hrtimer *hrt)
175 {
176 	hrtimer_cancel(hrt);
177 }
178 
179 static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
180 {
181 	struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id;
182 	struct arch_timer_context *ctx;
183 	struct timer_map map;
184 
185 	/*
186 	 * We may see a timer interrupt after vcpu_put() has been called which
187 	 * sets the CPU's vcpu pointer to NULL, because even though the timer
188 	 * has been disabled in timer_save_state(), the hardware interrupt
189 	 * signal may not have been retired from the interrupt controller yet.
190 	 */
191 	if (!vcpu)
192 		return IRQ_HANDLED;
193 
194 	get_timer_map(vcpu, &map);
195 
196 	if (irq == host_vtimer_irq)
197 		ctx = map.direct_vtimer;
198 	else
199 		ctx = map.direct_ptimer;
200 
201 	if (kvm_timer_should_fire(ctx))
202 		kvm_timer_update_irq(vcpu, true, ctx);
203 
204 	if (userspace_irqchip(vcpu->kvm) &&
205 	    !static_branch_unlikely(&has_gic_active_state))
206 		disable_percpu_irq(host_vtimer_irq);
207 
208 	return IRQ_HANDLED;
209 }
210 
211 static u64 kvm_timer_compute_delta(struct arch_timer_context *timer_ctx)
212 {
213 	u64 cval, now;
214 
215 	cval = timer_get_cval(timer_ctx);
216 	now = kvm_phys_timer_read() - timer_get_offset(timer_ctx);
217 
218 	if (now < cval) {
219 		u64 ns;
220 
221 		ns = cyclecounter_cyc2ns(timecounter->cc,
222 					 cval - now,
223 					 timecounter->mask,
224 					 &timecounter->frac);
225 		return ns;
226 	}
227 
228 	return 0;
229 }
230 
231 static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx)
232 {
233 	WARN_ON(timer_ctx && timer_ctx->loaded);
234 	return timer_ctx &&
235 		((timer_get_ctl(timer_ctx) &
236 		  (ARCH_TIMER_CTRL_IT_MASK | ARCH_TIMER_CTRL_ENABLE)) == ARCH_TIMER_CTRL_ENABLE);
237 }
238 
239 /*
240  * Returns the earliest expiration time in ns among guest timers.
241  * Note that it will return 0 if none of timers can fire.
242  */
243 static u64 kvm_timer_earliest_exp(struct kvm_vcpu *vcpu)
244 {
245 	u64 min_delta = ULLONG_MAX;
246 	int i;
247 
248 	for (i = 0; i < NR_KVM_TIMERS; i++) {
249 		struct arch_timer_context *ctx = &vcpu->arch.timer_cpu.timers[i];
250 
251 		WARN(ctx->loaded, "timer %d loaded\n", i);
252 		if (kvm_timer_irq_can_fire(ctx))
253 			min_delta = min(min_delta, kvm_timer_compute_delta(ctx));
254 	}
255 
256 	/* If none of timers can fire, then return 0 */
257 	if (min_delta == ULLONG_MAX)
258 		return 0;
259 
260 	return min_delta;
261 }
262 
263 static enum hrtimer_restart kvm_bg_timer_expire(struct hrtimer *hrt)
264 {
265 	struct arch_timer_cpu *timer;
266 	struct kvm_vcpu *vcpu;
267 	u64 ns;
268 
269 	timer = container_of(hrt, struct arch_timer_cpu, bg_timer);
270 	vcpu = container_of(timer, struct kvm_vcpu, arch.timer_cpu);
271 
272 	/*
273 	 * Check that the timer has really expired from the guest's
274 	 * PoV (NTP on the host may have forced it to expire
275 	 * early). If we should have slept longer, restart it.
276 	 */
277 	ns = kvm_timer_earliest_exp(vcpu);
278 	if (unlikely(ns)) {
279 		hrtimer_forward_now(hrt, ns_to_ktime(ns));
280 		return HRTIMER_RESTART;
281 	}
282 
283 	kvm_vcpu_wake_up(vcpu);
284 	return HRTIMER_NORESTART;
285 }
286 
287 static enum hrtimer_restart kvm_hrtimer_expire(struct hrtimer *hrt)
288 {
289 	struct arch_timer_context *ctx;
290 	struct kvm_vcpu *vcpu;
291 	u64 ns;
292 
293 	ctx = container_of(hrt, struct arch_timer_context, hrtimer);
294 	vcpu = ctx->vcpu;
295 
296 	trace_kvm_timer_hrtimer_expire(ctx);
297 
298 	/*
299 	 * Check that the timer has really expired from the guest's
300 	 * PoV (NTP on the host may have forced it to expire
301 	 * early). If not ready, schedule for a later time.
302 	 */
303 	ns = kvm_timer_compute_delta(ctx);
304 	if (unlikely(ns)) {
305 		hrtimer_forward_now(hrt, ns_to_ktime(ns));
306 		return HRTIMER_RESTART;
307 	}
308 
309 	kvm_timer_update_irq(vcpu, true, ctx);
310 	return HRTIMER_NORESTART;
311 }
312 
313 static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx)
314 {
315 	enum kvm_arch_timers index;
316 	u64 cval, now;
317 
318 	if (!timer_ctx)
319 		return false;
320 
321 	index = arch_timer_ctx_index(timer_ctx);
322 
323 	if (timer_ctx->loaded) {
324 		u32 cnt_ctl = 0;
325 
326 		switch (index) {
327 		case TIMER_VTIMER:
328 			cnt_ctl = read_sysreg_el0(SYS_CNTV_CTL);
329 			break;
330 		case TIMER_PTIMER:
331 			cnt_ctl = read_sysreg_el0(SYS_CNTP_CTL);
332 			break;
333 		case NR_KVM_TIMERS:
334 			/* GCC is braindead */
335 			cnt_ctl = 0;
336 			break;
337 		}
338 
339 		return  (cnt_ctl & ARCH_TIMER_CTRL_ENABLE) &&
340 		        (cnt_ctl & ARCH_TIMER_CTRL_IT_STAT) &&
341 		       !(cnt_ctl & ARCH_TIMER_CTRL_IT_MASK);
342 	}
343 
344 	if (!kvm_timer_irq_can_fire(timer_ctx))
345 		return false;
346 
347 	cval = timer_get_cval(timer_ctx);
348 	now = kvm_phys_timer_read() - timer_get_offset(timer_ctx);
349 
350 	return cval <= now;
351 }
352 
353 bool kvm_timer_is_pending(struct kvm_vcpu *vcpu)
354 {
355 	struct timer_map map;
356 
357 	get_timer_map(vcpu, &map);
358 
359 	return kvm_timer_should_fire(map.direct_vtimer) ||
360 	       kvm_timer_should_fire(map.direct_ptimer) ||
361 	       kvm_timer_should_fire(map.emul_ptimer);
362 }
363 
364 /*
365  * Reflect the timer output level into the kvm_run structure
366  */
367 void kvm_timer_update_run(struct kvm_vcpu *vcpu)
368 {
369 	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
370 	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
371 	struct kvm_sync_regs *regs = &vcpu->run->s.regs;
372 
373 	/* Populate the device bitmap with the timer states */
374 	regs->device_irq_level &= ~(KVM_ARM_DEV_EL1_VTIMER |
375 				    KVM_ARM_DEV_EL1_PTIMER);
376 	if (kvm_timer_should_fire(vtimer))
377 		regs->device_irq_level |= KVM_ARM_DEV_EL1_VTIMER;
378 	if (kvm_timer_should_fire(ptimer))
379 		regs->device_irq_level |= KVM_ARM_DEV_EL1_PTIMER;
380 }
381 
382 static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
383 				 struct arch_timer_context *timer_ctx)
384 {
385 	int ret;
386 
387 	timer_ctx->irq.level = new_level;
388 	trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_ctx->irq.irq,
389 				   timer_ctx->irq.level);
390 
391 	if (!userspace_irqchip(vcpu->kvm)) {
392 		ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
393 					  timer_ctx->irq.irq,
394 					  timer_ctx->irq.level,
395 					  timer_ctx);
396 		WARN_ON(ret);
397 	}
398 }
399 
400 /* Only called for a fully emulated timer */
401 static void timer_emulate(struct arch_timer_context *ctx)
402 {
403 	bool should_fire = kvm_timer_should_fire(ctx);
404 
405 	trace_kvm_timer_emulate(ctx, should_fire);
406 
407 	if (should_fire != ctx->irq.level) {
408 		kvm_timer_update_irq(ctx->vcpu, should_fire, ctx);
409 		return;
410 	}
411 
412 	/*
413 	 * If the timer can fire now, we don't need to have a soft timer
414 	 * scheduled for the future.  If the timer cannot fire at all,
415 	 * then we also don't need a soft timer.
416 	 */
417 	if (!kvm_timer_irq_can_fire(ctx)) {
418 		soft_timer_cancel(&ctx->hrtimer);
419 		return;
420 	}
421 
422 	soft_timer_start(&ctx->hrtimer, kvm_timer_compute_delta(ctx));
423 }
424 
425 static void timer_save_state(struct arch_timer_context *ctx)
426 {
427 	struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu);
428 	enum kvm_arch_timers index = arch_timer_ctx_index(ctx);
429 	unsigned long flags;
430 
431 	if (!timer->enabled)
432 		return;
433 
434 	local_irq_save(flags);
435 
436 	if (!ctx->loaded)
437 		goto out;
438 
439 	switch (index) {
440 	case TIMER_VTIMER:
441 		timer_set_ctl(ctx, read_sysreg_el0(SYS_CNTV_CTL));
442 		timer_set_cval(ctx, read_sysreg_el0(SYS_CNTV_CVAL));
443 
444 		/* Disable the timer */
445 		write_sysreg_el0(0, SYS_CNTV_CTL);
446 		isb();
447 
448 		break;
449 	case TIMER_PTIMER:
450 		timer_set_ctl(ctx, read_sysreg_el0(SYS_CNTP_CTL));
451 		timer_set_cval(ctx, read_sysreg_el0(SYS_CNTP_CVAL));
452 
453 		/* Disable the timer */
454 		write_sysreg_el0(0, SYS_CNTP_CTL);
455 		isb();
456 
457 		break;
458 	case NR_KVM_TIMERS:
459 		BUG();
460 	}
461 
462 	trace_kvm_timer_save_state(ctx);
463 
464 	ctx->loaded = false;
465 out:
466 	local_irq_restore(flags);
467 }
468 
469 /*
470  * Schedule the background timer before calling kvm_vcpu_halt, so that this
471  * thread is removed from its waitqueue and made runnable when there's a timer
472  * interrupt to handle.
473  */
474 static void kvm_timer_blocking(struct kvm_vcpu *vcpu)
475 {
476 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
477 	struct timer_map map;
478 
479 	get_timer_map(vcpu, &map);
480 
481 	/*
482 	 * If no timers are capable of raising interrupts (disabled or
483 	 * masked), then there's no more work for us to do.
484 	 */
485 	if (!kvm_timer_irq_can_fire(map.direct_vtimer) &&
486 	    !kvm_timer_irq_can_fire(map.direct_ptimer) &&
487 	    !kvm_timer_irq_can_fire(map.emul_ptimer))
488 		return;
489 
490 	/*
491 	 * At least one guest time will expire. Schedule a background timer.
492 	 * Set the earliest expiration time among the guest timers.
493 	 */
494 	soft_timer_start(&timer->bg_timer, kvm_timer_earliest_exp(vcpu));
495 }
496 
497 static void kvm_timer_unblocking(struct kvm_vcpu *vcpu)
498 {
499 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
500 
501 	soft_timer_cancel(&timer->bg_timer);
502 }
503 
504 static void timer_restore_state(struct arch_timer_context *ctx)
505 {
506 	struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu);
507 	enum kvm_arch_timers index = arch_timer_ctx_index(ctx);
508 	unsigned long flags;
509 
510 	if (!timer->enabled)
511 		return;
512 
513 	local_irq_save(flags);
514 
515 	if (ctx->loaded)
516 		goto out;
517 
518 	switch (index) {
519 	case TIMER_VTIMER:
520 		write_sysreg_el0(timer_get_cval(ctx), SYS_CNTV_CVAL);
521 		isb();
522 		write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTV_CTL);
523 		break;
524 	case TIMER_PTIMER:
525 		write_sysreg_el0(timer_get_cval(ctx), SYS_CNTP_CVAL);
526 		isb();
527 		write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTP_CTL);
528 		break;
529 	case NR_KVM_TIMERS:
530 		BUG();
531 	}
532 
533 	trace_kvm_timer_restore_state(ctx);
534 
535 	ctx->loaded = true;
536 out:
537 	local_irq_restore(flags);
538 }
539 
540 static void set_cntvoff(u64 cntvoff)
541 {
542 	kvm_call_hyp(__kvm_timer_set_cntvoff, cntvoff);
543 }
544 
545 static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, bool active)
546 {
547 	int r;
548 	r = irq_set_irqchip_state(ctx->host_timer_irq, IRQCHIP_STATE_ACTIVE, active);
549 	WARN_ON(r);
550 }
551 
552 static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
553 {
554 	struct kvm_vcpu *vcpu = ctx->vcpu;
555 	bool phys_active = false;
556 
557 	/*
558 	 * Update the timer output so that it is likely to match the
559 	 * state we're about to restore. If the timer expires between
560 	 * this point and the register restoration, we'll take the
561 	 * interrupt anyway.
562 	 */
563 	kvm_timer_update_irq(ctx->vcpu, kvm_timer_should_fire(ctx), ctx);
564 
565 	if (irqchip_in_kernel(vcpu->kvm))
566 		phys_active = kvm_vgic_map_is_active(vcpu, ctx->irq.irq);
567 
568 	phys_active |= ctx->irq.level;
569 
570 	set_timer_irq_phys_active(ctx, phys_active);
571 }
572 
573 static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)
574 {
575 	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
576 
577 	/*
578 	 * Update the timer output so that it is likely to match the
579 	 * state we're about to restore. If the timer expires between
580 	 * this point and the register restoration, we'll take the
581 	 * interrupt anyway.
582 	 */
583 	kvm_timer_update_irq(vcpu, kvm_timer_should_fire(vtimer), vtimer);
584 
585 	/*
586 	 * When using a userspace irqchip with the architected timers and a
587 	 * host interrupt controller that doesn't support an active state, we
588 	 * must still prevent continuously exiting from the guest, and
589 	 * therefore mask the physical interrupt by disabling it on the host
590 	 * interrupt controller when the virtual level is high, such that the
591 	 * guest can make forward progress.  Once we detect the output level
592 	 * being de-asserted, we unmask the interrupt again so that we exit
593 	 * from the guest when the timer fires.
594 	 */
595 	if (vtimer->irq.level)
596 		disable_percpu_irq(host_vtimer_irq);
597 	else
598 		enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
599 }
600 
601 void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)
602 {
603 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
604 	struct timer_map map;
605 
606 	if (unlikely(!timer->enabled))
607 		return;
608 
609 	get_timer_map(vcpu, &map);
610 
611 	if (static_branch_likely(&has_gic_active_state)) {
612 		kvm_timer_vcpu_load_gic(map.direct_vtimer);
613 		if (map.direct_ptimer)
614 			kvm_timer_vcpu_load_gic(map.direct_ptimer);
615 	} else {
616 		kvm_timer_vcpu_load_nogic(vcpu);
617 	}
618 
619 	set_cntvoff(timer_get_offset(map.direct_vtimer));
620 
621 	kvm_timer_unblocking(vcpu);
622 
623 	timer_restore_state(map.direct_vtimer);
624 	if (map.direct_ptimer)
625 		timer_restore_state(map.direct_ptimer);
626 
627 	if (map.emul_ptimer)
628 		timer_emulate(map.emul_ptimer);
629 }
630 
631 bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu)
632 {
633 	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
634 	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
635 	struct kvm_sync_regs *sregs = &vcpu->run->s.regs;
636 	bool vlevel, plevel;
637 
638 	if (likely(irqchip_in_kernel(vcpu->kvm)))
639 		return false;
640 
641 	vlevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_VTIMER;
642 	plevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_PTIMER;
643 
644 	return kvm_timer_should_fire(vtimer) != vlevel ||
645 	       kvm_timer_should_fire(ptimer) != plevel;
646 }
647 
648 void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
649 {
650 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
651 	struct timer_map map;
652 
653 	if (unlikely(!timer->enabled))
654 		return;
655 
656 	get_timer_map(vcpu, &map);
657 
658 	timer_save_state(map.direct_vtimer);
659 	if (map.direct_ptimer)
660 		timer_save_state(map.direct_ptimer);
661 
662 	/*
663 	 * Cancel soft timer emulation, because the only case where we
664 	 * need it after a vcpu_put is in the context of a sleeping VCPU, and
665 	 * in that case we already factor in the deadline for the physical
666 	 * timer when scheduling the bg_timer.
667 	 *
668 	 * In any case, we re-schedule the hrtimer for the physical timer when
669 	 * coming back to the VCPU thread in kvm_timer_vcpu_load().
670 	 */
671 	if (map.emul_ptimer)
672 		soft_timer_cancel(&map.emul_ptimer->hrtimer);
673 
674 	if (kvm_vcpu_is_blocking(vcpu))
675 		kvm_timer_blocking(vcpu);
676 
677 	/*
678 	 * The kernel may decide to run userspace after calling vcpu_put, so
679 	 * we reset cntvoff to 0 to ensure a consistent read between user
680 	 * accesses to the virtual counter and kernel access to the physical
681 	 * counter of non-VHE case. For VHE, the virtual counter uses a fixed
682 	 * virtual offset of zero, so no need to zero CNTVOFF_EL2 register.
683 	 */
684 	set_cntvoff(0);
685 }
686 
687 /*
688  * With a userspace irqchip we have to check if the guest de-asserted the
689  * timer and if so, unmask the timer irq signal on the host interrupt
690  * controller to ensure that we see future timer signals.
691  */
692 static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu)
693 {
694 	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
695 
696 	if (!kvm_timer_should_fire(vtimer)) {
697 		kvm_timer_update_irq(vcpu, false, vtimer);
698 		if (static_branch_likely(&has_gic_active_state))
699 			set_timer_irq_phys_active(vtimer, false);
700 		else
701 			enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
702 	}
703 }
704 
705 void kvm_timer_sync_user(struct kvm_vcpu *vcpu)
706 {
707 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
708 
709 	if (unlikely(!timer->enabled))
710 		return;
711 
712 	if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
713 		unmask_vtimer_irq_user(vcpu);
714 }
715 
716 int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
717 {
718 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
719 	struct timer_map map;
720 
721 	get_timer_map(vcpu, &map);
722 
723 	/*
724 	 * The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8
725 	 * and to 0 for ARMv7.  We provide an implementation that always
726 	 * resets the timer to be disabled and unmasked and is compliant with
727 	 * the ARMv7 architecture.
728 	 */
729 	timer_set_ctl(vcpu_vtimer(vcpu), 0);
730 	timer_set_ctl(vcpu_ptimer(vcpu), 0);
731 
732 	if (timer->enabled) {
733 		kvm_timer_update_irq(vcpu, false, vcpu_vtimer(vcpu));
734 		kvm_timer_update_irq(vcpu, false, vcpu_ptimer(vcpu));
735 
736 		if (irqchip_in_kernel(vcpu->kvm)) {
737 			kvm_vgic_reset_mapped_irq(vcpu, map.direct_vtimer->irq.irq);
738 			if (map.direct_ptimer)
739 				kvm_vgic_reset_mapped_irq(vcpu, map.direct_ptimer->irq.irq);
740 		}
741 	}
742 
743 	if (map.emul_ptimer)
744 		soft_timer_cancel(&map.emul_ptimer->hrtimer);
745 
746 	return 0;
747 }
748 
749 /* Make the updates of cntvoff for all vtimer contexts atomic */
750 static void update_vtimer_cntvoff(struct kvm_vcpu *vcpu, u64 cntvoff)
751 {
752 	unsigned long i;
753 	struct kvm *kvm = vcpu->kvm;
754 	struct kvm_vcpu *tmp;
755 
756 	mutex_lock(&kvm->lock);
757 	kvm_for_each_vcpu(i, tmp, kvm)
758 		timer_set_offset(vcpu_vtimer(tmp), cntvoff);
759 
760 	/*
761 	 * When called from the vcpu create path, the CPU being created is not
762 	 * included in the loop above, so we just set it here as well.
763 	 */
764 	timer_set_offset(vcpu_vtimer(vcpu), cntvoff);
765 	mutex_unlock(&kvm->lock);
766 }
767 
768 void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
769 {
770 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
771 	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
772 	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
773 
774 	vtimer->vcpu = vcpu;
775 	ptimer->vcpu = vcpu;
776 
777 	/* Synchronize cntvoff across all vtimers of a VM. */
778 	update_vtimer_cntvoff(vcpu, kvm_phys_timer_read());
779 	timer_set_offset(ptimer, 0);
780 
781 	hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
782 	timer->bg_timer.function = kvm_bg_timer_expire;
783 
784 	hrtimer_init(&vtimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
785 	hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
786 	vtimer->hrtimer.function = kvm_hrtimer_expire;
787 	ptimer->hrtimer.function = kvm_hrtimer_expire;
788 
789 	vtimer->irq.irq = default_vtimer_irq.irq;
790 	ptimer->irq.irq = default_ptimer_irq.irq;
791 
792 	vtimer->host_timer_irq = host_vtimer_irq;
793 	ptimer->host_timer_irq = host_ptimer_irq;
794 
795 	vtimer->host_timer_irq_flags = host_vtimer_irq_flags;
796 	ptimer->host_timer_irq_flags = host_ptimer_irq_flags;
797 }
798 
799 static void kvm_timer_init_interrupt(void *info)
800 {
801 	enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
802 	enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags);
803 }
804 
805 int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
806 {
807 	struct arch_timer_context *timer;
808 
809 	switch (regid) {
810 	case KVM_REG_ARM_TIMER_CTL:
811 		timer = vcpu_vtimer(vcpu);
812 		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
813 		break;
814 	case KVM_REG_ARM_TIMER_CNT:
815 		timer = vcpu_vtimer(vcpu);
816 		update_vtimer_cntvoff(vcpu, kvm_phys_timer_read() - value);
817 		break;
818 	case KVM_REG_ARM_TIMER_CVAL:
819 		timer = vcpu_vtimer(vcpu);
820 		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
821 		break;
822 	case KVM_REG_ARM_PTIMER_CTL:
823 		timer = vcpu_ptimer(vcpu);
824 		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
825 		break;
826 	case KVM_REG_ARM_PTIMER_CVAL:
827 		timer = vcpu_ptimer(vcpu);
828 		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
829 		break;
830 
831 	default:
832 		return -1;
833 	}
834 
835 	return 0;
836 }
837 
838 static u64 read_timer_ctl(struct arch_timer_context *timer)
839 {
840 	/*
841 	 * Set ISTATUS bit if it's expired.
842 	 * Note that according to ARMv8 ARM Issue A.k, ISTATUS bit is
843 	 * UNKNOWN when ENABLE bit is 0, so we chose to set ISTATUS bit
844 	 * regardless of ENABLE bit for our implementation convenience.
845 	 */
846 	u32 ctl = timer_get_ctl(timer);
847 
848 	if (!kvm_timer_compute_delta(timer))
849 		ctl |= ARCH_TIMER_CTRL_IT_STAT;
850 
851 	return ctl;
852 }
853 
854 u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
855 {
856 	switch (regid) {
857 	case KVM_REG_ARM_TIMER_CTL:
858 		return kvm_arm_timer_read(vcpu,
859 					  vcpu_vtimer(vcpu), TIMER_REG_CTL);
860 	case KVM_REG_ARM_TIMER_CNT:
861 		return kvm_arm_timer_read(vcpu,
862 					  vcpu_vtimer(vcpu), TIMER_REG_CNT);
863 	case KVM_REG_ARM_TIMER_CVAL:
864 		return kvm_arm_timer_read(vcpu,
865 					  vcpu_vtimer(vcpu), TIMER_REG_CVAL);
866 	case KVM_REG_ARM_PTIMER_CTL:
867 		return kvm_arm_timer_read(vcpu,
868 					  vcpu_ptimer(vcpu), TIMER_REG_CTL);
869 	case KVM_REG_ARM_PTIMER_CNT:
870 		return kvm_arm_timer_read(vcpu,
871 					  vcpu_ptimer(vcpu), TIMER_REG_CNT);
872 	case KVM_REG_ARM_PTIMER_CVAL:
873 		return kvm_arm_timer_read(vcpu,
874 					  vcpu_ptimer(vcpu), TIMER_REG_CVAL);
875 	}
876 	return (u64)-1;
877 }
878 
879 static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
880 			      struct arch_timer_context *timer,
881 			      enum kvm_arch_timer_regs treg)
882 {
883 	u64 val;
884 
885 	switch (treg) {
886 	case TIMER_REG_TVAL:
887 		val = timer_get_cval(timer) - kvm_phys_timer_read() + timer_get_offset(timer);
888 		val = lower_32_bits(val);
889 		break;
890 
891 	case TIMER_REG_CTL:
892 		val = read_timer_ctl(timer);
893 		break;
894 
895 	case TIMER_REG_CVAL:
896 		val = timer_get_cval(timer);
897 		break;
898 
899 	case TIMER_REG_CNT:
900 		val = kvm_phys_timer_read() - timer_get_offset(timer);
901 		break;
902 
903 	default:
904 		BUG();
905 	}
906 
907 	return val;
908 }
909 
910 u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu,
911 			      enum kvm_arch_timers tmr,
912 			      enum kvm_arch_timer_regs treg)
913 {
914 	u64 val;
915 
916 	preempt_disable();
917 	kvm_timer_vcpu_put(vcpu);
918 
919 	val = kvm_arm_timer_read(vcpu, vcpu_get_timer(vcpu, tmr), treg);
920 
921 	kvm_timer_vcpu_load(vcpu);
922 	preempt_enable();
923 
924 	return val;
925 }
926 
927 static void kvm_arm_timer_write(struct kvm_vcpu *vcpu,
928 				struct arch_timer_context *timer,
929 				enum kvm_arch_timer_regs treg,
930 				u64 val)
931 {
932 	switch (treg) {
933 	case TIMER_REG_TVAL:
934 		timer_set_cval(timer, kvm_phys_timer_read() - timer_get_offset(timer) + (s32)val);
935 		break;
936 
937 	case TIMER_REG_CTL:
938 		timer_set_ctl(timer, val & ~ARCH_TIMER_CTRL_IT_STAT);
939 		break;
940 
941 	case TIMER_REG_CVAL:
942 		timer_set_cval(timer, val);
943 		break;
944 
945 	default:
946 		BUG();
947 	}
948 }
949 
950 void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu,
951 				enum kvm_arch_timers tmr,
952 				enum kvm_arch_timer_regs treg,
953 				u64 val)
954 {
955 	preempt_disable();
956 	kvm_timer_vcpu_put(vcpu);
957 
958 	kvm_arm_timer_write(vcpu, vcpu_get_timer(vcpu, tmr), treg, val);
959 
960 	kvm_timer_vcpu_load(vcpu);
961 	preempt_enable();
962 }
963 
964 static int kvm_timer_starting_cpu(unsigned int cpu)
965 {
966 	kvm_timer_init_interrupt(NULL);
967 	return 0;
968 }
969 
970 static int kvm_timer_dying_cpu(unsigned int cpu)
971 {
972 	disable_percpu_irq(host_vtimer_irq);
973 	return 0;
974 }
975 
976 static int timer_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
977 {
978 	if (vcpu)
979 		irqd_set_forwarded_to_vcpu(d);
980 	else
981 		irqd_clr_forwarded_to_vcpu(d);
982 
983 	return 0;
984 }
985 
986 static int timer_irq_set_irqchip_state(struct irq_data *d,
987 				       enum irqchip_irq_state which, bool val)
988 {
989 	if (which != IRQCHIP_STATE_ACTIVE || !irqd_is_forwarded_to_vcpu(d))
990 		return irq_chip_set_parent_state(d, which, val);
991 
992 	if (val)
993 		irq_chip_mask_parent(d);
994 	else
995 		irq_chip_unmask_parent(d);
996 
997 	return 0;
998 }
999 
1000 static void timer_irq_eoi(struct irq_data *d)
1001 {
1002 	if (!irqd_is_forwarded_to_vcpu(d))
1003 		irq_chip_eoi_parent(d);
1004 }
1005 
1006 static void timer_irq_ack(struct irq_data *d)
1007 {
1008 	d = d->parent_data;
1009 	if (d->chip->irq_ack)
1010 		d->chip->irq_ack(d);
1011 }
1012 
1013 static struct irq_chip timer_chip = {
1014 	.name			= "KVM",
1015 	.irq_ack		= timer_irq_ack,
1016 	.irq_mask		= irq_chip_mask_parent,
1017 	.irq_unmask		= irq_chip_unmask_parent,
1018 	.irq_eoi		= timer_irq_eoi,
1019 	.irq_set_type		= irq_chip_set_type_parent,
1020 	.irq_set_vcpu_affinity	= timer_irq_set_vcpu_affinity,
1021 	.irq_set_irqchip_state	= timer_irq_set_irqchip_state,
1022 };
1023 
1024 static int timer_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
1025 				  unsigned int nr_irqs, void *arg)
1026 {
1027 	irq_hw_number_t hwirq = (uintptr_t)arg;
1028 
1029 	return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
1030 					     &timer_chip, NULL);
1031 }
1032 
1033 static void timer_irq_domain_free(struct irq_domain *domain, unsigned int virq,
1034 				  unsigned int nr_irqs)
1035 {
1036 }
1037 
1038 static const struct irq_domain_ops timer_domain_ops = {
1039 	.alloc	= timer_irq_domain_alloc,
1040 	.free	= timer_irq_domain_free,
1041 };
1042 
1043 static struct irq_ops arch_timer_irq_ops = {
1044 	.get_input_level = kvm_arch_timer_get_input_level,
1045 };
1046 
1047 static void kvm_irq_fixup_flags(unsigned int virq, u32 *flags)
1048 {
1049 	*flags = irq_get_trigger_type(virq);
1050 	if (*flags != IRQF_TRIGGER_HIGH && *flags != IRQF_TRIGGER_LOW) {
1051 		kvm_err("Invalid trigger for timer IRQ%d, assuming level low\n",
1052 			virq);
1053 		*flags = IRQF_TRIGGER_LOW;
1054 	}
1055 }
1056 
1057 static int kvm_irq_init(struct arch_timer_kvm_info *info)
1058 {
1059 	struct irq_domain *domain = NULL;
1060 
1061 	if (info->virtual_irq <= 0) {
1062 		kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n",
1063 			info->virtual_irq);
1064 		return -ENODEV;
1065 	}
1066 
1067 	host_vtimer_irq = info->virtual_irq;
1068 	kvm_irq_fixup_flags(host_vtimer_irq, &host_vtimer_irq_flags);
1069 
1070 	if (kvm_vgic_global_state.no_hw_deactivation) {
1071 		struct fwnode_handle *fwnode;
1072 		struct irq_data *data;
1073 
1074 		fwnode = irq_domain_alloc_named_fwnode("kvm-timer");
1075 		if (!fwnode)
1076 			return -ENOMEM;
1077 
1078 		/* Assume both vtimer and ptimer in the same parent */
1079 		data = irq_get_irq_data(host_vtimer_irq);
1080 		domain = irq_domain_create_hierarchy(data->domain, 0,
1081 						     NR_KVM_TIMERS, fwnode,
1082 						     &timer_domain_ops, NULL);
1083 		if (!domain) {
1084 			irq_domain_free_fwnode(fwnode);
1085 			return -ENOMEM;
1086 		}
1087 
1088 		arch_timer_irq_ops.flags |= VGIC_IRQ_SW_RESAMPLE;
1089 		WARN_ON(irq_domain_push_irq(domain, host_vtimer_irq,
1090 					    (void *)TIMER_VTIMER));
1091 	}
1092 
1093 	if (info->physical_irq > 0) {
1094 		host_ptimer_irq = info->physical_irq;
1095 		kvm_irq_fixup_flags(host_ptimer_irq, &host_ptimer_irq_flags);
1096 
1097 		if (domain)
1098 			WARN_ON(irq_domain_push_irq(domain, host_ptimer_irq,
1099 						    (void *)TIMER_PTIMER));
1100 	}
1101 
1102 	return 0;
1103 }
1104 
1105 int kvm_timer_hyp_init(bool has_gic)
1106 {
1107 	struct arch_timer_kvm_info *info;
1108 	int err;
1109 
1110 	info = arch_timer_get_kvm_info();
1111 	timecounter = &info->timecounter;
1112 
1113 	if (!timecounter->cc) {
1114 		kvm_err("kvm_arch_timer: uninitialized timecounter\n");
1115 		return -ENODEV;
1116 	}
1117 
1118 	err = kvm_irq_init(info);
1119 	if (err)
1120 		return err;
1121 
1122 	/* First, do the virtual EL1 timer irq */
1123 
1124 	err = request_percpu_irq(host_vtimer_irq, kvm_arch_timer_handler,
1125 				 "kvm guest vtimer", kvm_get_running_vcpus());
1126 	if (err) {
1127 		kvm_err("kvm_arch_timer: can't request vtimer interrupt %d (%d)\n",
1128 			host_vtimer_irq, err);
1129 		return err;
1130 	}
1131 
1132 	if (has_gic) {
1133 		err = irq_set_vcpu_affinity(host_vtimer_irq,
1134 					    kvm_get_running_vcpus());
1135 		if (err) {
1136 			kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
1137 			goto out_free_irq;
1138 		}
1139 
1140 		static_branch_enable(&has_gic_active_state);
1141 	}
1142 
1143 	kvm_debug("virtual timer IRQ%d\n", host_vtimer_irq);
1144 
1145 	/* Now let's do the physical EL1 timer irq */
1146 
1147 	if (info->physical_irq > 0) {
1148 		err = request_percpu_irq(host_ptimer_irq, kvm_arch_timer_handler,
1149 					 "kvm guest ptimer", kvm_get_running_vcpus());
1150 		if (err) {
1151 			kvm_err("kvm_arch_timer: can't request ptimer interrupt %d (%d)\n",
1152 				host_ptimer_irq, err);
1153 			return err;
1154 		}
1155 
1156 		if (has_gic) {
1157 			err = irq_set_vcpu_affinity(host_ptimer_irq,
1158 						    kvm_get_running_vcpus());
1159 			if (err) {
1160 				kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
1161 				goto out_free_irq;
1162 			}
1163 		}
1164 
1165 		kvm_debug("physical timer IRQ%d\n", host_ptimer_irq);
1166 	} else if (has_vhe()) {
1167 		kvm_err("kvm_arch_timer: invalid physical timer IRQ: %d\n",
1168 			info->physical_irq);
1169 		err = -ENODEV;
1170 		goto out_free_irq;
1171 	}
1172 
1173 	cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING,
1174 			  "kvm/arm/timer:starting", kvm_timer_starting_cpu,
1175 			  kvm_timer_dying_cpu);
1176 	return 0;
1177 out_free_irq:
1178 	free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus());
1179 	return err;
1180 }
1181 
1182 void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
1183 {
1184 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1185 
1186 	soft_timer_cancel(&timer->bg_timer);
1187 }
1188 
1189 static bool timer_irqs_are_valid(struct kvm_vcpu *vcpu)
1190 {
1191 	int vtimer_irq, ptimer_irq, ret;
1192 	unsigned long i;
1193 
1194 	vtimer_irq = vcpu_vtimer(vcpu)->irq.irq;
1195 	ret = kvm_vgic_set_owner(vcpu, vtimer_irq, vcpu_vtimer(vcpu));
1196 	if (ret)
1197 		return false;
1198 
1199 	ptimer_irq = vcpu_ptimer(vcpu)->irq.irq;
1200 	ret = kvm_vgic_set_owner(vcpu, ptimer_irq, vcpu_ptimer(vcpu));
1201 	if (ret)
1202 		return false;
1203 
1204 	kvm_for_each_vcpu(i, vcpu, vcpu->kvm) {
1205 		if (vcpu_vtimer(vcpu)->irq.irq != vtimer_irq ||
1206 		    vcpu_ptimer(vcpu)->irq.irq != ptimer_irq)
1207 			return false;
1208 	}
1209 
1210 	return true;
1211 }
1212 
1213 bool kvm_arch_timer_get_input_level(int vintid)
1214 {
1215 	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
1216 	struct arch_timer_context *timer;
1217 
1218 	if (vintid == vcpu_vtimer(vcpu)->irq.irq)
1219 		timer = vcpu_vtimer(vcpu);
1220 	else if (vintid == vcpu_ptimer(vcpu)->irq.irq)
1221 		timer = vcpu_ptimer(vcpu);
1222 	else
1223 		BUG();
1224 
1225 	return kvm_timer_should_fire(timer);
1226 }
1227 
1228 int kvm_timer_enable(struct kvm_vcpu *vcpu)
1229 {
1230 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1231 	struct timer_map map;
1232 	int ret;
1233 
1234 	if (timer->enabled)
1235 		return 0;
1236 
1237 	/* Without a VGIC we do not map virtual IRQs to physical IRQs */
1238 	if (!irqchip_in_kernel(vcpu->kvm))
1239 		goto no_vgic;
1240 
1241 	/*
1242 	 * At this stage, we have the guarantee that the vgic is both
1243 	 * available and initialized.
1244 	 */
1245 	if (!timer_irqs_are_valid(vcpu)) {
1246 		kvm_debug("incorrectly configured timer irqs\n");
1247 		return -EINVAL;
1248 	}
1249 
1250 	get_timer_map(vcpu, &map);
1251 
1252 	ret = kvm_vgic_map_phys_irq(vcpu,
1253 				    map.direct_vtimer->host_timer_irq,
1254 				    map.direct_vtimer->irq.irq,
1255 				    &arch_timer_irq_ops);
1256 	if (ret)
1257 		return ret;
1258 
1259 	if (map.direct_ptimer) {
1260 		ret = kvm_vgic_map_phys_irq(vcpu,
1261 					    map.direct_ptimer->host_timer_irq,
1262 					    map.direct_ptimer->irq.irq,
1263 					    &arch_timer_irq_ops);
1264 	}
1265 
1266 	if (ret)
1267 		return ret;
1268 
1269 no_vgic:
1270 	timer->enabled = 1;
1271 	return 0;
1272 }
1273 
1274 /*
1275  * On VHE system, we only need to configure the EL2 timer trap register once,
1276  * not for every world switch.
1277  * The host kernel runs at EL2 with HCR_EL2.TGE == 1,
1278  * and this makes those bits have no effect for the host kernel execution.
1279  */
1280 void kvm_timer_init_vhe(void)
1281 {
1282 	/* When HCR_EL2.E2H ==1, EL1PCEN and EL1PCTEN are shifted by 10 */
1283 	u32 cnthctl_shift = 10;
1284 	u64 val;
1285 
1286 	/*
1287 	 * VHE systems allow the guest direct access to the EL1 physical
1288 	 * timer/counter.
1289 	 */
1290 	val = read_sysreg(cnthctl_el2);
1291 	val |= (CNTHCTL_EL1PCEN << cnthctl_shift);
1292 	val |= (CNTHCTL_EL1PCTEN << cnthctl_shift);
1293 	write_sysreg(val, cnthctl_el2);
1294 }
1295 
1296 static void set_timer_irqs(struct kvm *kvm, int vtimer_irq, int ptimer_irq)
1297 {
1298 	struct kvm_vcpu *vcpu;
1299 	unsigned long i;
1300 
1301 	kvm_for_each_vcpu(i, vcpu, kvm) {
1302 		vcpu_vtimer(vcpu)->irq.irq = vtimer_irq;
1303 		vcpu_ptimer(vcpu)->irq.irq = ptimer_irq;
1304 	}
1305 }
1306 
1307 int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1308 {
1309 	int __user *uaddr = (int __user *)(long)attr->addr;
1310 	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
1311 	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
1312 	int irq;
1313 
1314 	if (!irqchip_in_kernel(vcpu->kvm))
1315 		return -EINVAL;
1316 
1317 	if (get_user(irq, uaddr))
1318 		return -EFAULT;
1319 
1320 	if (!(irq_is_ppi(irq)))
1321 		return -EINVAL;
1322 
1323 	if (vcpu->arch.timer_cpu.enabled)
1324 		return -EBUSY;
1325 
1326 	switch (attr->attr) {
1327 	case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1328 		set_timer_irqs(vcpu->kvm, irq, ptimer->irq.irq);
1329 		break;
1330 	case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1331 		set_timer_irqs(vcpu->kvm, vtimer->irq.irq, irq);
1332 		break;
1333 	default:
1334 		return -ENXIO;
1335 	}
1336 
1337 	return 0;
1338 }
1339 
1340 int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1341 {
1342 	int __user *uaddr = (int __user *)(long)attr->addr;
1343 	struct arch_timer_context *timer;
1344 	int irq;
1345 
1346 	switch (attr->attr) {
1347 	case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1348 		timer = vcpu_vtimer(vcpu);
1349 		break;
1350 	case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1351 		timer = vcpu_ptimer(vcpu);
1352 		break;
1353 	default:
1354 		return -ENXIO;
1355 	}
1356 
1357 	irq = timer->irq.irq;
1358 	return put_user(irq, uaddr);
1359 }
1360 
1361 int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1362 {
1363 	switch (attr->attr) {
1364 	case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1365 	case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1366 		return 0;
1367 	}
1368 
1369 	return -ENXIO;
1370 }
1371