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 #include <asm/kvm_nested.h>
20
21 #include <kvm/arm_vgic.h>
22 #include <kvm/arm_arch_timer.h>
23
24 #include "trace.h"
25
26 static struct timecounter *timecounter;
27 static unsigned int host_vtimer_irq;
28 static unsigned int host_ptimer_irq;
29 static u32 host_vtimer_irq_flags;
30 static u32 host_ptimer_irq_flags;
31
32 static DEFINE_STATIC_KEY_FALSE(has_gic_active_state);
33
34 static const u8 default_ppi[] = {
35 [TIMER_PTIMER] = 30,
36 [TIMER_VTIMER] = 27,
37 [TIMER_HPTIMER] = 26,
38 [TIMER_HVTIMER] = 28,
39 };
40
41 static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx);
42 static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
43 struct arch_timer_context *timer_ctx);
44 static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx);
45 static void kvm_arm_timer_write(struct kvm_vcpu *vcpu,
46 struct arch_timer_context *timer,
47 enum kvm_arch_timer_regs treg,
48 u64 val);
49 static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
50 struct arch_timer_context *timer,
51 enum kvm_arch_timer_regs treg);
52 static bool kvm_arch_timer_get_input_level(int vintid);
53
54 static struct irq_ops arch_timer_irq_ops = {
55 .get_input_level = kvm_arch_timer_get_input_level,
56 };
57
58 static int nr_timers(struct kvm_vcpu *vcpu)
59 {
60 if (!vcpu_has_nv(vcpu))
61 return NR_KVM_EL0_TIMERS;
62
63 return NR_KVM_TIMERS;
64 }
65
66 u32 timer_get_ctl(struct arch_timer_context *ctxt)
67 {
68 struct kvm_vcpu *vcpu = ctxt->vcpu;
69
70 switch(arch_timer_ctx_index(ctxt)) {
71 case TIMER_VTIMER:
72 return __vcpu_sys_reg(vcpu, CNTV_CTL_EL0);
73 case TIMER_PTIMER:
74 return __vcpu_sys_reg(vcpu, CNTP_CTL_EL0);
75 case TIMER_HVTIMER:
76 return __vcpu_sys_reg(vcpu, CNTHV_CTL_EL2);
77 case TIMER_HPTIMER:
78 return __vcpu_sys_reg(vcpu, CNTHP_CTL_EL2);
79 default:
80 WARN_ON(1);
81 return 0;
82 }
83 }
84
85 u64 timer_get_cval(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, CNTV_CVAL_EL0);
92 case TIMER_PTIMER:
93 return __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);
94 case TIMER_HVTIMER:
95 return __vcpu_sys_reg(vcpu, CNTHV_CVAL_EL2);
96 case TIMER_HPTIMER:
97 return __vcpu_sys_reg(vcpu, CNTHP_CVAL_EL2);
98 default:
99 WARN_ON(1);
100 return 0;
101 }
102 }
103
104 static u64 timer_get_offset(struct arch_timer_context *ctxt)
105 {
106 u64 offset = 0;
107
108 if (!ctxt)
109 return 0;
110
111 if (ctxt->offset.vm_offset)
112 offset += *ctxt->offset.vm_offset;
113 if (ctxt->offset.vcpu_offset)
114 offset += *ctxt->offset.vcpu_offset;
115
116 return offset;
117 }
118
119 static void timer_set_ctl(struct arch_timer_context *ctxt, u32 ctl)
120 {
121 struct kvm_vcpu *vcpu = ctxt->vcpu;
122
123 switch(arch_timer_ctx_index(ctxt)) {
124 case TIMER_VTIMER:
125 __vcpu_sys_reg(vcpu, CNTV_CTL_EL0) = ctl;
126 break;
127 case TIMER_PTIMER:
128 __vcpu_sys_reg(vcpu, CNTP_CTL_EL0) = ctl;
129 break;
130 case TIMER_HVTIMER:
131 __vcpu_sys_reg(vcpu, CNTHV_CTL_EL2) = ctl;
132 break;
133 case TIMER_HPTIMER:
134 __vcpu_sys_reg(vcpu, CNTHP_CTL_EL2) = ctl;
135 break;
136 default:
137 WARN_ON(1);
138 }
139 }
140
141 static void timer_set_cval(struct arch_timer_context *ctxt, u64 cval)
142 {
143 struct kvm_vcpu *vcpu = ctxt->vcpu;
144
145 switch(arch_timer_ctx_index(ctxt)) {
146 case TIMER_VTIMER:
147 __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0) = cval;
148 break;
149 case TIMER_PTIMER:
150 __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0) = cval;
151 break;
152 case TIMER_HVTIMER:
153 __vcpu_sys_reg(vcpu, CNTHV_CVAL_EL2) = cval;
154 break;
155 case TIMER_HPTIMER:
156 __vcpu_sys_reg(vcpu, CNTHP_CVAL_EL2) = cval;
157 break;
158 default:
159 WARN_ON(1);
160 }
161 }
162
163 static void timer_set_offset(struct arch_timer_context *ctxt, u64 offset)
164 {
165 if (!ctxt->offset.vm_offset) {
166 WARN(offset, "timer %ld\n", arch_timer_ctx_index(ctxt));
167 return;
168 }
169
170 WRITE_ONCE(*ctxt->offset.vm_offset, offset);
171 }
172
173 u64 kvm_phys_timer_read(void)
174 {
175 return timecounter->cc->read(timecounter->cc);
176 }
177
178 void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map)
179 {
180 if (vcpu_has_nv(vcpu)) {
181 if (is_hyp_ctxt(vcpu)) {
182 map->direct_vtimer = vcpu_hvtimer(vcpu);
183 map->direct_ptimer = vcpu_hptimer(vcpu);
184 map->emul_vtimer = vcpu_vtimer(vcpu);
185 map->emul_ptimer = vcpu_ptimer(vcpu);
186 } else {
187 map->direct_vtimer = vcpu_vtimer(vcpu);
188 map->direct_ptimer = vcpu_ptimer(vcpu);
189 map->emul_vtimer = vcpu_hvtimer(vcpu);
190 map->emul_ptimer = vcpu_hptimer(vcpu);
191 }
192 } else if (has_vhe()) {
193 map->direct_vtimer = vcpu_vtimer(vcpu);
194 map->direct_ptimer = vcpu_ptimer(vcpu);
195 map->emul_vtimer = NULL;
196 map->emul_ptimer = NULL;
197 } else {
198 map->direct_vtimer = vcpu_vtimer(vcpu);
199 map->direct_ptimer = NULL;
200 map->emul_vtimer = NULL;
201 map->emul_ptimer = vcpu_ptimer(vcpu);
202 }
203
204 trace_kvm_get_timer_map(vcpu->vcpu_id, map);
205 }
206
207 static inline bool userspace_irqchip(struct kvm *kvm)
208 {
209 return static_branch_unlikely(&userspace_irqchip_in_use) &&
210 unlikely(!irqchip_in_kernel(kvm));
211 }
212
213 static void soft_timer_start(struct hrtimer *hrt, u64 ns)
214 {
215 hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns),
216 HRTIMER_MODE_ABS_HARD);
217 }
218
219 static void soft_timer_cancel(struct hrtimer *hrt)
220 {
221 hrtimer_cancel(hrt);
222 }
223
224 static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
225 {
226 struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id;
227 struct arch_timer_context *ctx;
228 struct timer_map map;
229
230 /*
231 * We may see a timer interrupt after vcpu_put() has been called which
232 * sets the CPU's vcpu pointer to NULL, because even though the timer
233 * has been disabled in timer_save_state(), the hardware interrupt
234 * signal may not have been retired from the interrupt controller yet.
235 */
236 if (!vcpu)
237 return IRQ_HANDLED;
238
239 get_timer_map(vcpu, &map);
240
241 if (irq == host_vtimer_irq)
242 ctx = map.direct_vtimer;
243 else
244 ctx = map.direct_ptimer;
245
246 if (kvm_timer_should_fire(ctx))
247 kvm_timer_update_irq(vcpu, true, ctx);
248
249 if (userspace_irqchip(vcpu->kvm) &&
250 !static_branch_unlikely(&has_gic_active_state))
251 disable_percpu_irq(host_vtimer_irq);
252
253 return IRQ_HANDLED;
254 }
255
256 static u64 kvm_counter_compute_delta(struct arch_timer_context *timer_ctx,
257 u64 val)
258 {
259 u64 now = kvm_phys_timer_read() - timer_get_offset(timer_ctx);
260
261 if (now < val) {
262 u64 ns;
263
264 ns = cyclecounter_cyc2ns(timecounter->cc,
265 val - now,
266 timecounter->mask,
267 &timer_ctx->ns_frac);
268 return ns;
269 }
270
271 return 0;
272 }
273
274 static u64 kvm_timer_compute_delta(struct arch_timer_context *timer_ctx)
275 {
276 return kvm_counter_compute_delta(timer_ctx, timer_get_cval(timer_ctx));
277 }
278
279 static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx)
280 {
281 WARN_ON(timer_ctx && timer_ctx->loaded);
282 return timer_ctx &&
283 ((timer_get_ctl(timer_ctx) &
284 (ARCH_TIMER_CTRL_IT_MASK | ARCH_TIMER_CTRL_ENABLE)) == ARCH_TIMER_CTRL_ENABLE);
285 }
286
287 static bool vcpu_has_wfit_active(struct kvm_vcpu *vcpu)
288 {
289 return (cpus_have_final_cap(ARM64_HAS_WFXT) &&
290 vcpu_get_flag(vcpu, IN_WFIT));
291 }
292
293 static u64 wfit_delay_ns(struct kvm_vcpu *vcpu)
294 {
295 u64 val = vcpu_get_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu));
296 struct arch_timer_context *ctx;
297
298 ctx = is_hyp_ctxt(vcpu) ? vcpu_hvtimer(vcpu) : vcpu_vtimer(vcpu);
299
300 return kvm_counter_compute_delta(ctx, val);
301 }
302
303 /*
304 * Returns the earliest expiration time in ns among guest timers.
305 * Note that it will return 0 if none of timers can fire.
306 */
307 static u64 kvm_timer_earliest_exp(struct kvm_vcpu *vcpu)
308 {
309 u64 min_delta = ULLONG_MAX;
310 int i;
311
312 for (i = 0; i < nr_timers(vcpu); i++) {
313 struct arch_timer_context *ctx = &vcpu->arch.timer_cpu.timers[i];
314
315 WARN(ctx->loaded, "timer %d loaded\n", i);
316 if (kvm_timer_irq_can_fire(ctx))
317 min_delta = min(min_delta, kvm_timer_compute_delta(ctx));
318 }
319
320 if (vcpu_has_wfit_active(vcpu))
321 min_delta = min(min_delta, wfit_delay_ns(vcpu));
322
323 /* If none of timers can fire, then return 0 */
324 if (min_delta == ULLONG_MAX)
325 return 0;
326
327 return min_delta;
328 }
329
330 static enum hrtimer_restart kvm_bg_timer_expire(struct hrtimer *hrt)
331 {
332 struct arch_timer_cpu *timer;
333 struct kvm_vcpu *vcpu;
334 u64 ns;
335
336 timer = container_of(hrt, struct arch_timer_cpu, bg_timer);
337 vcpu = container_of(timer, struct kvm_vcpu, arch.timer_cpu);
338
339 /*
340 * Check that the timer has really expired from the guest's
341 * PoV (NTP on the host may have forced it to expire
342 * early). If we should have slept longer, restart it.
343 */
344 ns = kvm_timer_earliest_exp(vcpu);
345 if (unlikely(ns)) {
346 hrtimer_forward_now(hrt, ns_to_ktime(ns));
347 return HRTIMER_RESTART;
348 }
349
350 kvm_vcpu_wake_up(vcpu);
351 return HRTIMER_NORESTART;
352 }
353
354 static enum hrtimer_restart kvm_hrtimer_expire(struct hrtimer *hrt)
355 {
356 struct arch_timer_context *ctx;
357 struct kvm_vcpu *vcpu;
358 u64 ns;
359
360 ctx = container_of(hrt, struct arch_timer_context, hrtimer);
361 vcpu = ctx->vcpu;
362
363 trace_kvm_timer_hrtimer_expire(ctx);
364
365 /*
366 * Check that the timer has really expired from the guest's
367 * PoV (NTP on the host may have forced it to expire
368 * early). If not ready, schedule for a later time.
369 */
370 ns = kvm_timer_compute_delta(ctx);
371 if (unlikely(ns)) {
372 hrtimer_forward_now(hrt, ns_to_ktime(ns));
373 return HRTIMER_RESTART;
374 }
375
376 kvm_timer_update_irq(vcpu, true, ctx);
377 return HRTIMER_NORESTART;
378 }
379
380 static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx)
381 {
382 enum kvm_arch_timers index;
383 u64 cval, now;
384
385 if (!timer_ctx)
386 return false;
387
388 index = arch_timer_ctx_index(timer_ctx);
389
390 if (timer_ctx->loaded) {
391 u32 cnt_ctl = 0;
392
393 switch (index) {
394 case TIMER_VTIMER:
395 case TIMER_HVTIMER:
396 cnt_ctl = read_sysreg_el0(SYS_CNTV_CTL);
397 break;
398 case TIMER_PTIMER:
399 case TIMER_HPTIMER:
400 cnt_ctl = read_sysreg_el0(SYS_CNTP_CTL);
401 break;
402 case NR_KVM_TIMERS:
403 /* GCC is braindead */
404 cnt_ctl = 0;
405 break;
406 }
407
408 return (cnt_ctl & ARCH_TIMER_CTRL_ENABLE) &&
409 (cnt_ctl & ARCH_TIMER_CTRL_IT_STAT) &&
410 !(cnt_ctl & ARCH_TIMER_CTRL_IT_MASK);
411 }
412
413 if (!kvm_timer_irq_can_fire(timer_ctx))
414 return false;
415
416 cval = timer_get_cval(timer_ctx);
417 now = kvm_phys_timer_read() - timer_get_offset(timer_ctx);
418
419 return cval <= now;
420 }
421
422 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
423 {
424 return vcpu_has_wfit_active(vcpu) && wfit_delay_ns(vcpu) == 0;
425 }
426
427 /*
428 * Reflect the timer output level into the kvm_run structure
429 */
430 void kvm_timer_update_run(struct kvm_vcpu *vcpu)
431 {
432 struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
433 struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
434 struct kvm_sync_regs *regs = &vcpu->run->s.regs;
435
436 /* Populate the device bitmap with the timer states */
437 regs->device_irq_level &= ~(KVM_ARM_DEV_EL1_VTIMER |
438 KVM_ARM_DEV_EL1_PTIMER);
439 if (kvm_timer_should_fire(vtimer))
440 regs->device_irq_level |= KVM_ARM_DEV_EL1_VTIMER;
441 if (kvm_timer_should_fire(ptimer))
442 regs->device_irq_level |= KVM_ARM_DEV_EL1_PTIMER;
443 }
444
445 static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
446 struct arch_timer_context *timer_ctx)
447 {
448 int ret;
449
450 timer_ctx->irq.level = new_level;
451 trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_irq(timer_ctx),
452 timer_ctx->irq.level);
453
454 if (!userspace_irqchip(vcpu->kvm)) {
455 ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu,
456 timer_irq(timer_ctx),
457 timer_ctx->irq.level,
458 timer_ctx);
459 WARN_ON(ret);
460 }
461 }
462
463 /* Only called for a fully emulated timer */
464 static void timer_emulate(struct arch_timer_context *ctx)
465 {
466 bool should_fire = kvm_timer_should_fire(ctx);
467
468 trace_kvm_timer_emulate(ctx, should_fire);
469
470 if (should_fire != ctx->irq.level) {
471 kvm_timer_update_irq(ctx->vcpu, should_fire, ctx);
472 return;
473 }
474
475 /*
476 * If the timer can fire now, we don't need to have a soft timer
477 * scheduled for the future. If the timer cannot fire at all,
478 * then we also don't need a soft timer.
479 */
480 if (should_fire || !kvm_timer_irq_can_fire(ctx))
481 return;
482
483 soft_timer_start(&ctx->hrtimer, kvm_timer_compute_delta(ctx));
484 }
485
486 static void set_cntvoff(u64 cntvoff)
487 {
488 kvm_call_hyp(__kvm_timer_set_cntvoff, cntvoff);
489 }
490
491 static void set_cntpoff(u64 cntpoff)
492 {
493 if (has_cntpoff())
494 write_sysreg_s(cntpoff, SYS_CNTPOFF_EL2);
495 }
496
497 static void timer_save_state(struct arch_timer_context *ctx)
498 {
499 struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu);
500 enum kvm_arch_timers index = arch_timer_ctx_index(ctx);
501 unsigned long flags;
502
503 if (!timer->enabled)
504 return;
505
506 local_irq_save(flags);
507
508 if (!ctx->loaded)
509 goto out;
510
511 switch (index) {
512 u64 cval;
513
514 case TIMER_VTIMER:
515 case TIMER_HVTIMER:
516 timer_set_ctl(ctx, read_sysreg_el0(SYS_CNTV_CTL));
517 timer_set_cval(ctx, read_sysreg_el0(SYS_CNTV_CVAL));
518
519 /* Disable the timer */
520 write_sysreg_el0(0, SYS_CNTV_CTL);
521 isb();
522
523 /*
524 * The kernel may decide to run userspace after
525 * calling vcpu_put, so we reset cntvoff to 0 to
526 * ensure a consistent read between user accesses to
527 * the virtual counter and kernel access to the
528 * physical counter of non-VHE case.
529 *
530 * For VHE, the virtual counter uses a fixed virtual
531 * offset of zero, so no need to zero CNTVOFF_EL2
532 * register, but this is actually useful when switching
533 * between EL1/vEL2 with NV.
534 *
535 * Do it unconditionally, as this is either unavoidable
536 * or dirt cheap.
537 */
538 set_cntvoff(0);
539 break;
540 case TIMER_PTIMER:
541 case TIMER_HPTIMER:
542 timer_set_ctl(ctx, read_sysreg_el0(SYS_CNTP_CTL));
543 cval = read_sysreg_el0(SYS_CNTP_CVAL);
544
545 cval -= timer_get_offset(ctx);
546
547 timer_set_cval(ctx, cval);
548
549 /* Disable the timer */
550 write_sysreg_el0(0, SYS_CNTP_CTL);
551 isb();
552
553 set_cntpoff(0);
554 break;
555 case NR_KVM_TIMERS:
556 BUG();
557 }
558
559 trace_kvm_timer_save_state(ctx);
560
561 ctx->loaded = false;
562 out:
563 local_irq_restore(flags);
564 }
565
566 /*
567 * Schedule the background timer before calling kvm_vcpu_halt, so that this
568 * thread is removed from its waitqueue and made runnable when there's a timer
569 * interrupt to handle.
570 */
571 static void kvm_timer_blocking(struct kvm_vcpu *vcpu)
572 {
573 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
574 struct timer_map map;
575
576 get_timer_map(vcpu, &map);
577
578 /*
579 * If no timers are capable of raising interrupts (disabled or
580 * masked), then there's no more work for us to do.
581 */
582 if (!kvm_timer_irq_can_fire(map.direct_vtimer) &&
583 !kvm_timer_irq_can_fire(map.direct_ptimer) &&
584 !kvm_timer_irq_can_fire(map.emul_vtimer) &&
585 !kvm_timer_irq_can_fire(map.emul_ptimer) &&
586 !vcpu_has_wfit_active(vcpu))
587 return;
588
589 /*
590 * At least one guest time will expire. Schedule a background timer.
591 * Set the earliest expiration time among the guest timers.
592 */
593 soft_timer_start(&timer->bg_timer, kvm_timer_earliest_exp(vcpu));
594 }
595
596 static void kvm_timer_unblocking(struct kvm_vcpu *vcpu)
597 {
598 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
599
600 soft_timer_cancel(&timer->bg_timer);
601 }
602
603 static void timer_restore_state(struct arch_timer_context *ctx)
604 {
605 struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu);
606 enum kvm_arch_timers index = arch_timer_ctx_index(ctx);
607 unsigned long flags;
608
609 if (!timer->enabled)
610 return;
611
612 local_irq_save(flags);
613
614 if (ctx->loaded)
615 goto out;
616
617 switch (index) {
618 u64 cval, offset;
619
620 case TIMER_VTIMER:
621 case TIMER_HVTIMER:
622 set_cntvoff(timer_get_offset(ctx));
623 write_sysreg_el0(timer_get_cval(ctx), SYS_CNTV_CVAL);
624 isb();
625 write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTV_CTL);
626 break;
627 case TIMER_PTIMER:
628 case TIMER_HPTIMER:
629 cval = timer_get_cval(ctx);
630 offset = timer_get_offset(ctx);
631 set_cntpoff(offset);
632 cval += offset;
633 write_sysreg_el0(cval, SYS_CNTP_CVAL);
634 isb();
635 write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTP_CTL);
636 break;
637 case NR_KVM_TIMERS:
638 BUG();
639 }
640
641 trace_kvm_timer_restore_state(ctx);
642
643 ctx->loaded = true;
644 out:
645 local_irq_restore(flags);
646 }
647
648 static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, bool active)
649 {
650 int r;
651 r = irq_set_irqchip_state(ctx->host_timer_irq, IRQCHIP_STATE_ACTIVE, active);
652 WARN_ON(r);
653 }
654
655 static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
656 {
657 struct kvm_vcpu *vcpu = ctx->vcpu;
658 bool phys_active = false;
659
660 /*
661 * Update the timer output so that it is likely to match the
662 * state we're about to restore. If the timer expires between
663 * this point and the register restoration, we'll take the
664 * interrupt anyway.
665 */
666 kvm_timer_update_irq(ctx->vcpu, kvm_timer_should_fire(ctx), ctx);
667
668 if (irqchip_in_kernel(vcpu->kvm))
669 phys_active = kvm_vgic_map_is_active(vcpu, timer_irq(ctx));
670
671 phys_active |= ctx->irq.level;
672
673 set_timer_irq_phys_active(ctx, phys_active);
674 }
675
676 static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)
677 {
678 struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
679
680 /*
681 * Update the timer output so that it is likely to match the
682 * state we're about to restore. If the timer expires between
683 * this point and the register restoration, we'll take the
684 * interrupt anyway.
685 */
686 kvm_timer_update_irq(vcpu, kvm_timer_should_fire(vtimer), vtimer);
687
688 /*
689 * When using a userspace irqchip with the architected timers and a
690 * host interrupt controller that doesn't support an active state, we
691 * must still prevent continuously exiting from the guest, and
692 * therefore mask the physical interrupt by disabling it on the host
693 * interrupt controller when the virtual level is high, such that the
694 * guest can make forward progress. Once we detect the output level
695 * being de-asserted, we unmask the interrupt again so that we exit
696 * from the guest when the timer fires.
697 */
698 if (vtimer->irq.level)
699 disable_percpu_irq(host_vtimer_irq);
700 else
701 enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
702 }
703
704 /* If _pred is true, set bit in _set, otherwise set it in _clr */
705 #define assign_clear_set_bit(_pred, _bit, _clr, _set) \
706 do { \
707 if (_pred) \
708 (_set) |= (_bit); \
709 else \
710 (_clr) |= (_bit); \
711 } while (0)
712
713 static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
714 struct timer_map *map)
715 {
716 int hw, ret;
717
718 if (!irqchip_in_kernel(vcpu->kvm))
719 return;
720
721 /*
722 * We only ever unmap the vtimer irq on a VHE system that runs nested
723 * virtualization, in which case we have both a valid emul_vtimer,
724 * emul_ptimer, direct_vtimer, and direct_ptimer.
725 *
726 * Since this is called from kvm_timer_vcpu_load(), a change between
727 * vEL2 and vEL1/0 will have just happened, and the timer_map will
728 * represent this, and therefore we switch the emul/direct mappings
729 * below.
730 */
731 hw = kvm_vgic_get_map(vcpu, timer_irq(map->direct_vtimer));
732 if (hw < 0) {
733 kvm_vgic_unmap_phys_irq(vcpu, timer_irq(map->emul_vtimer));
734 kvm_vgic_unmap_phys_irq(vcpu, timer_irq(map->emul_ptimer));
735
736 ret = kvm_vgic_map_phys_irq(vcpu,
737 map->direct_vtimer->host_timer_irq,
738 timer_irq(map->direct_vtimer),
739 &arch_timer_irq_ops);
740 WARN_ON_ONCE(ret);
741 ret = kvm_vgic_map_phys_irq(vcpu,
742 map->direct_ptimer->host_timer_irq,
743 timer_irq(map->direct_ptimer),
744 &arch_timer_irq_ops);
745 WARN_ON_ONCE(ret);
746
747 /*
748 * The virtual offset behaviour is "interesting", as it
749 * always applies when HCR_EL2.E2H==0, but only when
750 * accessed from EL1 when HCR_EL2.E2H==1. So make sure we
751 * track E2H when putting the HV timer in "direct" mode.
752 */
753 if (map->direct_vtimer == vcpu_hvtimer(vcpu)) {
754 struct arch_timer_offset *offs = &map->direct_vtimer->offset;
755
756 if (vcpu_el2_e2h_is_set(vcpu))
757 offs->vcpu_offset = NULL;
758 else
759 offs->vcpu_offset = &__vcpu_sys_reg(vcpu, CNTVOFF_EL2);
760 }
761 }
762 }
763
764 static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map)
765 {
766 bool tpt, tpc;
767 u64 clr, set;
768
769 /*
770 * No trapping gets configured here with nVHE. See
771 * __timer_enable_traps(), which is where the stuff happens.
772 */
773 if (!has_vhe())
774 return;
775
776 /*
777 * Our default policy is not to trap anything. As we progress
778 * within this function, reality kicks in and we start adding
779 * traps based on emulation requirements.
780 */
781 tpt = tpc = false;
782
783 /*
784 * We have two possibility to deal with a physical offset:
785 *
786 * - Either we have CNTPOFF (yay!) or the offset is 0:
787 * we let the guest freely access the HW
788 *
789 * - or neither of these condition apply:
790 * we trap accesses to the HW, but still use it
791 * after correcting the physical offset
792 */
793 if (!has_cntpoff() && timer_get_offset(map->direct_ptimer))
794 tpt = tpc = true;
795
796 /*
797 * Apply the enable bits that the guest hypervisor has requested for
798 * its own guest. We can only add traps that wouldn't have been set
799 * above.
800 */
801 if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) {
802 u64 val = __vcpu_sys_reg(vcpu, CNTHCTL_EL2);
803
804 /* Use the VHE format for mental sanity */
805 if (!vcpu_el2_e2h_is_set(vcpu))
806 val = (val & (CNTHCTL_EL1PCEN | CNTHCTL_EL1PCTEN)) << 10;
807
808 tpt |= !(val & (CNTHCTL_EL1PCEN << 10));
809 tpc |= !(val & (CNTHCTL_EL1PCTEN << 10));
810 }
811
812 /*
813 * Now that we have collected our requirements, compute the
814 * trap and enable bits.
815 */
816 set = 0;
817 clr = 0;
818
819 assign_clear_set_bit(tpt, CNTHCTL_EL1PCEN << 10, set, clr);
820 assign_clear_set_bit(tpc, CNTHCTL_EL1PCTEN << 10, set, clr);
821
822 /* This only happens on VHE, so use the CNTHCTL_EL2 accessor. */
823 sysreg_clear_set(cnthctl_el2, clr, set);
824 }
825
826 void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)
827 {
828 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
829 struct timer_map map;
830
831 if (unlikely(!timer->enabled))
832 return;
833
834 get_timer_map(vcpu, &map);
835
836 if (static_branch_likely(&has_gic_active_state)) {
837 if (vcpu_has_nv(vcpu))
838 kvm_timer_vcpu_load_nested_switch(vcpu, &map);
839
840 kvm_timer_vcpu_load_gic(map.direct_vtimer);
841 if (map.direct_ptimer)
842 kvm_timer_vcpu_load_gic(map.direct_ptimer);
843 } else {
844 kvm_timer_vcpu_load_nogic(vcpu);
845 }
846
847 kvm_timer_unblocking(vcpu);
848
849 timer_restore_state(map.direct_vtimer);
850 if (map.direct_ptimer)
851 timer_restore_state(map.direct_ptimer);
852 if (map.emul_vtimer)
853 timer_emulate(map.emul_vtimer);
854 if (map.emul_ptimer)
855 timer_emulate(map.emul_ptimer);
856
857 timer_set_traps(vcpu, &map);
858 }
859
860 bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu)
861 {
862 struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
863 struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
864 struct kvm_sync_regs *sregs = &vcpu->run->s.regs;
865 bool vlevel, plevel;
866
867 if (likely(irqchip_in_kernel(vcpu->kvm)))
868 return false;
869
870 vlevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_VTIMER;
871 plevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_PTIMER;
872
873 return kvm_timer_should_fire(vtimer) != vlevel ||
874 kvm_timer_should_fire(ptimer) != plevel;
875 }
876
877 void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
878 {
879 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
880 struct timer_map map;
881
882 if (unlikely(!timer->enabled))
883 return;
884
885 get_timer_map(vcpu, &map);
886
887 timer_save_state(map.direct_vtimer);
888 if (map.direct_ptimer)
889 timer_save_state(map.direct_ptimer);
890
891 /*
892 * Cancel soft timer emulation, because the only case where we
893 * need it after a vcpu_put is in the context of a sleeping VCPU, and
894 * in that case we already factor in the deadline for the physical
895 * timer when scheduling the bg_timer.
896 *
897 * In any case, we re-schedule the hrtimer for the physical timer when
898 * coming back to the VCPU thread in kvm_timer_vcpu_load().
899 */
900 if (map.emul_vtimer)
901 soft_timer_cancel(&map.emul_vtimer->hrtimer);
902 if (map.emul_ptimer)
903 soft_timer_cancel(&map.emul_ptimer->hrtimer);
904
905 if (kvm_vcpu_is_blocking(vcpu))
906 kvm_timer_blocking(vcpu);
907 }
908
909 /*
910 * With a userspace irqchip we have to check if the guest de-asserted the
911 * timer and if so, unmask the timer irq signal on the host interrupt
912 * controller to ensure that we see future timer signals.
913 */
914 static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu)
915 {
916 struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
917
918 if (!kvm_timer_should_fire(vtimer)) {
919 kvm_timer_update_irq(vcpu, false, vtimer);
920 if (static_branch_likely(&has_gic_active_state))
921 set_timer_irq_phys_active(vtimer, false);
922 else
923 enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
924 }
925 }
926
927 void kvm_timer_sync_user(struct kvm_vcpu *vcpu)
928 {
929 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
930
931 if (unlikely(!timer->enabled))
932 return;
933
934 if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
935 unmask_vtimer_irq_user(vcpu);
936 }
937
938 void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
939 {
940 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
941 struct timer_map map;
942
943 get_timer_map(vcpu, &map);
944
945 /*
946 * The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8
947 * and to 0 for ARMv7. We provide an implementation that always
948 * resets the timer to be disabled and unmasked and is compliant with
949 * the ARMv7 architecture.
950 */
951 for (int i = 0; i < nr_timers(vcpu); i++)
952 timer_set_ctl(vcpu_get_timer(vcpu, i), 0);
953
954 /*
955 * A vcpu running at EL2 is in charge of the offset applied to
956 * the virtual timer, so use the physical VM offset, and point
957 * the vcpu offset to CNTVOFF_EL2.
958 */
959 if (vcpu_has_nv(vcpu)) {
960 struct arch_timer_offset *offs = &vcpu_vtimer(vcpu)->offset;
961
962 offs->vcpu_offset = &__vcpu_sys_reg(vcpu, CNTVOFF_EL2);
963 offs->vm_offset = &vcpu->kvm->arch.timer_data.poffset;
964 }
965
966 if (timer->enabled) {
967 for (int i = 0; i < nr_timers(vcpu); i++)
968 kvm_timer_update_irq(vcpu, false,
969 vcpu_get_timer(vcpu, i));
970
971 if (irqchip_in_kernel(vcpu->kvm)) {
972 kvm_vgic_reset_mapped_irq(vcpu, timer_irq(map.direct_vtimer));
973 if (map.direct_ptimer)
974 kvm_vgic_reset_mapped_irq(vcpu, timer_irq(map.direct_ptimer));
975 }
976 }
977
978 if (map.emul_vtimer)
979 soft_timer_cancel(&map.emul_vtimer->hrtimer);
980 if (map.emul_ptimer)
981 soft_timer_cancel(&map.emul_ptimer->hrtimer);
982 }
983
984 static void timer_context_init(struct kvm_vcpu *vcpu, int timerid)
985 {
986 struct arch_timer_context *ctxt = vcpu_get_timer(vcpu, timerid);
987 struct kvm *kvm = vcpu->kvm;
988
989 ctxt->vcpu = vcpu;
990
991 if (timerid == TIMER_VTIMER)
992 ctxt->offset.vm_offset = &kvm->arch.timer_data.voffset;
993 else
994 ctxt->offset.vm_offset = &kvm->arch.timer_data.poffset;
995
996 hrtimer_init(&ctxt->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
997 ctxt->hrtimer.function = kvm_hrtimer_expire;
998
999 switch (timerid) {
1000 case TIMER_PTIMER:
1001 case TIMER_HPTIMER:
1002 ctxt->host_timer_irq = host_ptimer_irq;
1003 break;
1004 case TIMER_VTIMER:
1005 case TIMER_HVTIMER:
1006 ctxt->host_timer_irq = host_vtimer_irq;
1007 break;
1008 }
1009 }
1010
1011 void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
1012 {
1013 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1014
1015 for (int i = 0; i < NR_KVM_TIMERS; i++)
1016 timer_context_init(vcpu, i);
1017
1018 /* Synchronize offsets across timers of a VM if not already provided */
1019 if (!test_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET, &vcpu->kvm->arch.flags)) {
1020 timer_set_offset(vcpu_vtimer(vcpu), kvm_phys_timer_read());
1021 timer_set_offset(vcpu_ptimer(vcpu), 0);
1022 }
1023
1024 hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
1025 timer->bg_timer.function = kvm_bg_timer_expire;
1026 }
1027
1028 void kvm_timer_init_vm(struct kvm *kvm)
1029 {
1030 for (int i = 0; i < NR_KVM_TIMERS; i++)
1031 kvm->arch.timer_data.ppi[i] = default_ppi[i];
1032 }
1033
1034 void kvm_timer_cpu_up(void)
1035 {
1036 enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
1037 if (host_ptimer_irq)
1038 enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags);
1039 }
1040
1041 void kvm_timer_cpu_down(void)
1042 {
1043 disable_percpu_irq(host_vtimer_irq);
1044 if (host_ptimer_irq)
1045 disable_percpu_irq(host_ptimer_irq);
1046 }
1047
1048 int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
1049 {
1050 struct arch_timer_context *timer;
1051
1052 switch (regid) {
1053 case KVM_REG_ARM_TIMER_CTL:
1054 timer = vcpu_vtimer(vcpu);
1055 kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
1056 break;
1057 case KVM_REG_ARM_TIMER_CNT:
1058 if (!test_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET,
1059 &vcpu->kvm->arch.flags)) {
1060 timer = vcpu_vtimer(vcpu);
1061 timer_set_offset(timer, kvm_phys_timer_read() - value);
1062 }
1063 break;
1064 case KVM_REG_ARM_TIMER_CVAL:
1065 timer = vcpu_vtimer(vcpu);
1066 kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
1067 break;
1068 case KVM_REG_ARM_PTIMER_CTL:
1069 timer = vcpu_ptimer(vcpu);
1070 kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
1071 break;
1072 case KVM_REG_ARM_PTIMER_CNT:
1073 if (!test_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET,
1074 &vcpu->kvm->arch.flags)) {
1075 timer = vcpu_ptimer(vcpu);
1076 timer_set_offset(timer, kvm_phys_timer_read() - value);
1077 }
1078 break;
1079 case KVM_REG_ARM_PTIMER_CVAL:
1080 timer = vcpu_ptimer(vcpu);
1081 kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
1082 break;
1083
1084 default:
1085 return -1;
1086 }
1087
1088 return 0;
1089 }
1090
1091 static u64 read_timer_ctl(struct arch_timer_context *timer)
1092 {
1093 /*
1094 * Set ISTATUS bit if it's expired.
1095 * Note that according to ARMv8 ARM Issue A.k, ISTATUS bit is
1096 * UNKNOWN when ENABLE bit is 0, so we chose to set ISTATUS bit
1097 * regardless of ENABLE bit for our implementation convenience.
1098 */
1099 u32 ctl = timer_get_ctl(timer);
1100
1101 if (!kvm_timer_compute_delta(timer))
1102 ctl |= ARCH_TIMER_CTRL_IT_STAT;
1103
1104 return ctl;
1105 }
1106
1107 u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
1108 {
1109 switch (regid) {
1110 case KVM_REG_ARM_TIMER_CTL:
1111 return kvm_arm_timer_read(vcpu,
1112 vcpu_vtimer(vcpu), TIMER_REG_CTL);
1113 case KVM_REG_ARM_TIMER_CNT:
1114 return kvm_arm_timer_read(vcpu,
1115 vcpu_vtimer(vcpu), TIMER_REG_CNT);
1116 case KVM_REG_ARM_TIMER_CVAL:
1117 return kvm_arm_timer_read(vcpu,
1118 vcpu_vtimer(vcpu), TIMER_REG_CVAL);
1119 case KVM_REG_ARM_PTIMER_CTL:
1120 return kvm_arm_timer_read(vcpu,
1121 vcpu_ptimer(vcpu), TIMER_REG_CTL);
1122 case KVM_REG_ARM_PTIMER_CNT:
1123 return kvm_arm_timer_read(vcpu,
1124 vcpu_ptimer(vcpu), TIMER_REG_CNT);
1125 case KVM_REG_ARM_PTIMER_CVAL:
1126 return kvm_arm_timer_read(vcpu,
1127 vcpu_ptimer(vcpu), TIMER_REG_CVAL);
1128 }
1129 return (u64)-1;
1130 }
1131
1132 static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
1133 struct arch_timer_context *timer,
1134 enum kvm_arch_timer_regs treg)
1135 {
1136 u64 val;
1137
1138 switch (treg) {
1139 case TIMER_REG_TVAL:
1140 val = timer_get_cval(timer) - kvm_phys_timer_read() + timer_get_offset(timer);
1141 val = lower_32_bits(val);
1142 break;
1143
1144 case TIMER_REG_CTL:
1145 val = read_timer_ctl(timer);
1146 break;
1147
1148 case TIMER_REG_CVAL:
1149 val = timer_get_cval(timer);
1150 break;
1151
1152 case TIMER_REG_CNT:
1153 val = kvm_phys_timer_read() - timer_get_offset(timer);
1154 break;
1155
1156 case TIMER_REG_VOFF:
1157 val = *timer->offset.vcpu_offset;
1158 break;
1159
1160 default:
1161 BUG();
1162 }
1163
1164 return val;
1165 }
1166
1167 u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu,
1168 enum kvm_arch_timers tmr,
1169 enum kvm_arch_timer_regs treg)
1170 {
1171 struct arch_timer_context *timer;
1172 struct timer_map map;
1173 u64 val;
1174
1175 get_timer_map(vcpu, &map);
1176 timer = vcpu_get_timer(vcpu, tmr);
1177
1178 if (timer == map.emul_vtimer || timer == map.emul_ptimer)
1179 return kvm_arm_timer_read(vcpu, timer, treg);
1180
1181 preempt_disable();
1182 timer_save_state(timer);
1183
1184 val = kvm_arm_timer_read(vcpu, timer, treg);
1185
1186 timer_restore_state(timer);
1187 preempt_enable();
1188
1189 return val;
1190 }
1191
1192 static void kvm_arm_timer_write(struct kvm_vcpu *vcpu,
1193 struct arch_timer_context *timer,
1194 enum kvm_arch_timer_regs treg,
1195 u64 val)
1196 {
1197 switch (treg) {
1198 case TIMER_REG_TVAL:
1199 timer_set_cval(timer, kvm_phys_timer_read() - timer_get_offset(timer) + (s32)val);
1200 break;
1201
1202 case TIMER_REG_CTL:
1203 timer_set_ctl(timer, val & ~ARCH_TIMER_CTRL_IT_STAT);
1204 break;
1205
1206 case TIMER_REG_CVAL:
1207 timer_set_cval(timer, val);
1208 break;
1209
1210 case TIMER_REG_VOFF:
1211 *timer->offset.vcpu_offset = val;
1212 break;
1213
1214 default:
1215 BUG();
1216 }
1217 }
1218
1219 void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu,
1220 enum kvm_arch_timers tmr,
1221 enum kvm_arch_timer_regs treg,
1222 u64 val)
1223 {
1224 struct arch_timer_context *timer;
1225 struct timer_map map;
1226
1227 get_timer_map(vcpu, &map);
1228 timer = vcpu_get_timer(vcpu, tmr);
1229 if (timer == map.emul_vtimer || timer == map.emul_ptimer) {
1230 soft_timer_cancel(&timer->hrtimer);
1231 kvm_arm_timer_write(vcpu, timer, treg, val);
1232 timer_emulate(timer);
1233 } else {
1234 preempt_disable();
1235 timer_save_state(timer);
1236 kvm_arm_timer_write(vcpu, timer, treg, val);
1237 timer_restore_state(timer);
1238 preempt_enable();
1239 }
1240 }
1241
1242 static int timer_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
1243 {
1244 if (vcpu)
1245 irqd_set_forwarded_to_vcpu(d);
1246 else
1247 irqd_clr_forwarded_to_vcpu(d);
1248
1249 return 0;
1250 }
1251
1252 static int timer_irq_set_irqchip_state(struct irq_data *d,
1253 enum irqchip_irq_state which, bool val)
1254 {
1255 if (which != IRQCHIP_STATE_ACTIVE || !irqd_is_forwarded_to_vcpu(d))
1256 return irq_chip_set_parent_state(d, which, val);
1257
1258 if (val)
1259 irq_chip_mask_parent(d);
1260 else
1261 irq_chip_unmask_parent(d);
1262
1263 return 0;
1264 }
1265
1266 static void timer_irq_eoi(struct irq_data *d)
1267 {
1268 if (!irqd_is_forwarded_to_vcpu(d))
1269 irq_chip_eoi_parent(d);
1270 }
1271
1272 static void timer_irq_ack(struct irq_data *d)
1273 {
1274 d = d->parent_data;
1275 if (d->chip->irq_ack)
1276 d->chip->irq_ack(d);
1277 }
1278
1279 static struct irq_chip timer_chip = {
1280 .name = "KVM",
1281 .irq_ack = timer_irq_ack,
1282 .irq_mask = irq_chip_mask_parent,
1283 .irq_unmask = irq_chip_unmask_parent,
1284 .irq_eoi = timer_irq_eoi,
1285 .irq_set_type = irq_chip_set_type_parent,
1286 .irq_set_vcpu_affinity = timer_irq_set_vcpu_affinity,
1287 .irq_set_irqchip_state = timer_irq_set_irqchip_state,
1288 };
1289
1290 static int timer_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
1291 unsigned int nr_irqs, void *arg)
1292 {
1293 irq_hw_number_t hwirq = (uintptr_t)arg;
1294
1295 return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
1296 &timer_chip, NULL);
1297 }
1298
1299 static void timer_irq_domain_free(struct irq_domain *domain, unsigned int virq,
1300 unsigned int nr_irqs)
1301 {
1302 }
1303
1304 static const struct irq_domain_ops timer_domain_ops = {
1305 .alloc = timer_irq_domain_alloc,
1306 .free = timer_irq_domain_free,
1307 };
1308
1309 static void kvm_irq_fixup_flags(unsigned int virq, u32 *flags)
1310 {
1311 *flags = irq_get_trigger_type(virq);
1312 if (*flags != IRQF_TRIGGER_HIGH && *flags != IRQF_TRIGGER_LOW) {
1313 kvm_err("Invalid trigger for timer IRQ%d, assuming level low\n",
1314 virq);
1315 *flags = IRQF_TRIGGER_LOW;
1316 }
1317 }
1318
1319 static int kvm_irq_init(struct arch_timer_kvm_info *info)
1320 {
1321 struct irq_domain *domain = NULL;
1322
1323 if (info->virtual_irq <= 0) {
1324 kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n",
1325 info->virtual_irq);
1326 return -ENODEV;
1327 }
1328
1329 host_vtimer_irq = info->virtual_irq;
1330 kvm_irq_fixup_flags(host_vtimer_irq, &host_vtimer_irq_flags);
1331
1332 if (kvm_vgic_global_state.no_hw_deactivation) {
1333 struct fwnode_handle *fwnode;
1334 struct irq_data *data;
1335
1336 fwnode = irq_domain_alloc_named_fwnode("kvm-timer");
1337 if (!fwnode)
1338 return -ENOMEM;
1339
1340 /* Assume both vtimer and ptimer in the same parent */
1341 data = irq_get_irq_data(host_vtimer_irq);
1342 domain = irq_domain_create_hierarchy(data->domain, 0,
1343 NR_KVM_TIMERS, fwnode,
1344 &timer_domain_ops, NULL);
1345 if (!domain) {
1346 irq_domain_free_fwnode(fwnode);
1347 return -ENOMEM;
1348 }
1349
1350 arch_timer_irq_ops.flags |= VGIC_IRQ_SW_RESAMPLE;
1351 WARN_ON(irq_domain_push_irq(domain, host_vtimer_irq,
1352 (void *)TIMER_VTIMER));
1353 }
1354
1355 if (info->physical_irq > 0) {
1356 host_ptimer_irq = info->physical_irq;
1357 kvm_irq_fixup_flags(host_ptimer_irq, &host_ptimer_irq_flags);
1358
1359 if (domain)
1360 WARN_ON(irq_domain_push_irq(domain, host_ptimer_irq,
1361 (void *)TIMER_PTIMER));
1362 }
1363
1364 return 0;
1365 }
1366
1367 int __init kvm_timer_hyp_init(bool has_gic)
1368 {
1369 struct arch_timer_kvm_info *info;
1370 int err;
1371
1372 info = arch_timer_get_kvm_info();
1373 timecounter = &info->timecounter;
1374
1375 if (!timecounter->cc) {
1376 kvm_err("kvm_arch_timer: uninitialized timecounter\n");
1377 return -ENODEV;
1378 }
1379
1380 err = kvm_irq_init(info);
1381 if (err)
1382 return err;
1383
1384 /* First, do the virtual EL1 timer irq */
1385
1386 err = request_percpu_irq(host_vtimer_irq, kvm_arch_timer_handler,
1387 "kvm guest vtimer", kvm_get_running_vcpus());
1388 if (err) {
1389 kvm_err("kvm_arch_timer: can't request vtimer interrupt %d (%d)\n",
1390 host_vtimer_irq, err);
1391 return err;
1392 }
1393
1394 if (has_gic) {
1395 err = irq_set_vcpu_affinity(host_vtimer_irq,
1396 kvm_get_running_vcpus());
1397 if (err) {
1398 kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
1399 goto out_free_vtimer_irq;
1400 }
1401
1402 static_branch_enable(&has_gic_active_state);
1403 }
1404
1405 kvm_debug("virtual timer IRQ%d\n", host_vtimer_irq);
1406
1407 /* Now let's do the physical EL1 timer irq */
1408
1409 if (info->physical_irq > 0) {
1410 err = request_percpu_irq(host_ptimer_irq, kvm_arch_timer_handler,
1411 "kvm guest ptimer", kvm_get_running_vcpus());
1412 if (err) {
1413 kvm_err("kvm_arch_timer: can't request ptimer interrupt %d (%d)\n",
1414 host_ptimer_irq, err);
1415 goto out_free_vtimer_irq;
1416 }
1417
1418 if (has_gic) {
1419 err = irq_set_vcpu_affinity(host_ptimer_irq,
1420 kvm_get_running_vcpus());
1421 if (err) {
1422 kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
1423 goto out_free_ptimer_irq;
1424 }
1425 }
1426
1427 kvm_debug("physical timer IRQ%d\n", host_ptimer_irq);
1428 } else if (has_vhe()) {
1429 kvm_err("kvm_arch_timer: invalid physical timer IRQ: %d\n",
1430 info->physical_irq);
1431 err = -ENODEV;
1432 goto out_free_vtimer_irq;
1433 }
1434
1435 return 0;
1436
1437 out_free_ptimer_irq:
1438 if (info->physical_irq > 0)
1439 free_percpu_irq(host_ptimer_irq, kvm_get_running_vcpus());
1440 out_free_vtimer_irq:
1441 free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus());
1442 return err;
1443 }
1444
1445 void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
1446 {
1447 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1448
1449 soft_timer_cancel(&timer->bg_timer);
1450 }
1451
1452 static bool timer_irqs_are_valid(struct kvm_vcpu *vcpu)
1453 {
1454 u32 ppis = 0;
1455 bool valid;
1456
1457 mutex_lock(&vcpu->kvm->arch.config_lock);
1458
1459 for (int i = 0; i < nr_timers(vcpu); i++) {
1460 struct arch_timer_context *ctx;
1461 int irq;
1462
1463 ctx = vcpu_get_timer(vcpu, i);
1464 irq = timer_irq(ctx);
1465 if (kvm_vgic_set_owner(vcpu, irq, ctx))
1466 break;
1467
1468 /*
1469 * We know by construction that we only have PPIs, so
1470 * all values are less than 32.
1471 */
1472 ppis |= BIT(irq);
1473 }
1474
1475 valid = hweight32(ppis) == nr_timers(vcpu);
1476
1477 if (valid)
1478 set_bit(KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE, &vcpu->kvm->arch.flags);
1479
1480 mutex_unlock(&vcpu->kvm->arch.config_lock);
1481
1482 return valid;
1483 }
1484
1485 static bool kvm_arch_timer_get_input_level(int vintid)
1486 {
1487 struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
1488
1489 if (WARN(!vcpu, "No vcpu context!\n"))
1490 return false;
1491
1492 for (int i = 0; i < nr_timers(vcpu); i++) {
1493 struct arch_timer_context *ctx;
1494
1495 ctx = vcpu_get_timer(vcpu, i);
1496 if (timer_irq(ctx) == vintid)
1497 return kvm_timer_should_fire(ctx);
1498 }
1499
1500 /* A timer IRQ has fired, but no matching timer was found? */
1501 WARN_RATELIMIT(1, "timer INTID%d unknown\n", vintid);
1502
1503 return false;
1504 }
1505
1506 int kvm_timer_enable(struct kvm_vcpu *vcpu)
1507 {
1508 struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1509 struct timer_map map;
1510 int ret;
1511
1512 if (timer->enabled)
1513 return 0;
1514
1515 /* Without a VGIC we do not map virtual IRQs to physical IRQs */
1516 if (!irqchip_in_kernel(vcpu->kvm))
1517 goto no_vgic;
1518
1519 /*
1520 * At this stage, we have the guarantee that the vgic is both
1521 * available and initialized.
1522 */
1523 if (!timer_irqs_are_valid(vcpu)) {
1524 kvm_debug("incorrectly configured timer irqs\n");
1525 return -EINVAL;
1526 }
1527
1528 get_timer_map(vcpu, &map);
1529
1530 ret = kvm_vgic_map_phys_irq(vcpu,
1531 map.direct_vtimer->host_timer_irq,
1532 timer_irq(map.direct_vtimer),
1533 &arch_timer_irq_ops);
1534 if (ret)
1535 return ret;
1536
1537 if (map.direct_ptimer) {
1538 ret = kvm_vgic_map_phys_irq(vcpu,
1539 map.direct_ptimer->host_timer_irq,
1540 timer_irq(map.direct_ptimer),
1541 &arch_timer_irq_ops);
1542 }
1543
1544 if (ret)
1545 return ret;
1546
1547 no_vgic:
1548 timer->enabled = 1;
1549 return 0;
1550 }
1551
1552 /* If we have CNTPOFF, permanently set ECV to enable it */
1553 void kvm_timer_init_vhe(void)
1554 {
1555 if (cpus_have_final_cap(ARM64_HAS_ECV_CNTPOFF))
1556 sysreg_clear_set(cnthctl_el2, 0, CNTHCTL_ECV);
1557 }
1558
1559 int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1560 {
1561 int __user *uaddr = (int __user *)(long)attr->addr;
1562 int irq, idx, ret = 0;
1563
1564 if (!irqchip_in_kernel(vcpu->kvm))
1565 return -EINVAL;
1566
1567 if (get_user(irq, uaddr))
1568 return -EFAULT;
1569
1570 if (!(irq_is_ppi(irq)))
1571 return -EINVAL;
1572
1573 mutex_lock(&vcpu->kvm->arch.config_lock);
1574
1575 if (test_bit(KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE,
1576 &vcpu->kvm->arch.flags)) {
1577 ret = -EBUSY;
1578 goto out;
1579 }
1580
1581 switch (attr->attr) {
1582 case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1583 idx = TIMER_VTIMER;
1584 break;
1585 case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1586 idx = TIMER_PTIMER;
1587 break;
1588 case KVM_ARM_VCPU_TIMER_IRQ_HVTIMER:
1589 idx = TIMER_HVTIMER;
1590 break;
1591 case KVM_ARM_VCPU_TIMER_IRQ_HPTIMER:
1592 idx = TIMER_HPTIMER;
1593 break;
1594 default:
1595 ret = -ENXIO;
1596 goto out;
1597 }
1598
1599 /*
1600 * We cannot validate the IRQ unicity before we run, so take it at
1601 * face value. The verdict will be given on first vcpu run, for each
1602 * vcpu. Yes this is late. Blame it on the stupid API.
1603 */
1604 vcpu->kvm->arch.timer_data.ppi[idx] = irq;
1605
1606 out:
1607 mutex_unlock(&vcpu->kvm->arch.config_lock);
1608 return ret;
1609 }
1610
1611 int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1612 {
1613 int __user *uaddr = (int __user *)(long)attr->addr;
1614 struct arch_timer_context *timer;
1615 int irq;
1616
1617 switch (attr->attr) {
1618 case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1619 timer = vcpu_vtimer(vcpu);
1620 break;
1621 case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1622 timer = vcpu_ptimer(vcpu);
1623 break;
1624 case KVM_ARM_VCPU_TIMER_IRQ_HVTIMER:
1625 timer = vcpu_hvtimer(vcpu);
1626 break;
1627 case KVM_ARM_VCPU_TIMER_IRQ_HPTIMER:
1628 timer = vcpu_hptimer(vcpu);
1629 break;
1630 default:
1631 return -ENXIO;
1632 }
1633
1634 irq = timer_irq(timer);
1635 return put_user(irq, uaddr);
1636 }
1637
1638 int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1639 {
1640 switch (attr->attr) {
1641 case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1642 case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1643 case KVM_ARM_VCPU_TIMER_IRQ_HVTIMER:
1644 case KVM_ARM_VCPU_TIMER_IRQ_HPTIMER:
1645 return 0;
1646 }
1647
1648 return -ENXIO;
1649 }
1650
1651 int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm,
1652 struct kvm_arm_counter_offset *offset)
1653 {
1654 int ret = 0;
1655
1656 if (offset->reserved)
1657 return -EINVAL;
1658
1659 mutex_lock(&kvm->lock);
1660
1661 if (lock_all_vcpus(kvm)) {
1662 set_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET, &kvm->arch.flags);
1663
1664 /*
1665 * If userspace decides to set the offset using this
1666 * API rather than merely restoring the counter
1667 * values, the offset applies to both the virtual and
1668 * physical views.
1669 */
1670 kvm->arch.timer_data.voffset = offset->counter_offset;
1671 kvm->arch.timer_data.poffset = offset->counter_offset;
1672
1673 unlock_all_vcpus(kvm);
1674 } else {
1675 ret = -EBUSY;
1676 }
1677
1678 mutex_unlock(&kvm->lock);
1679
1680 return ret;
1681 }
1682
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