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   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
  25static struct timecounter *timecounter;
  26static unsigned int host_vtimer_irq;
  27static unsigned int host_ptimer_irq;
  28static u32 host_vtimer_irq_flags;
  29static u32 host_ptimer_irq_flags;
  30
  31static DEFINE_STATIC_KEY_FALSE(has_gic_active_state);
  32
  33static const struct kvm_irq_level default_ptimer_irq = {
  34	.irq	= 30,
  35	.level	= 1,
  36};
  37
  38static const struct kvm_irq_level default_vtimer_irq = {
  39	.irq	= 27,
  40	.level	= 1,
  41};
  42
  43static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx);
  44static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
  45				 struct arch_timer_context *timer_ctx);
  46static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx);
  47static 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);
  51static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
  52			      struct arch_timer_context *timer,
  53			      enum kvm_arch_timer_regs treg);
  54
  55u32 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
  70u64 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
  85static 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
  97static 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
 113static 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
 129static 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
 142u64 kvm_phys_timer_read(void)
 143{
 144	return timecounter->cc->read(timecounter->cc);
 145}
 146
 147static 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
 162static 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
 168static 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
 174static void soft_timer_cancel(struct hrtimer *hrt)
 175{
 176	hrtimer_cancel(hrt);
 177}
 178
 179static 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
 211static 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
 231static 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 */
 243static 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
 263static 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
 287static 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
 313static 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
 353bool 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 */
 367void 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
 382static 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 */
 401static 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
 425static 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;
 465out:
 466	local_irq_restore(flags);
 467}
 468
 469/*
 470 * Schedule the background timer before calling kvm_vcpu_block, so that this
 471 * thread is removed from its waitqueue and made runnable when there's a timer
 472 * interrupt to handle.
 473 */
 474static 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
 497static 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
 504static 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;
 536out:
 537	local_irq_restore(flags);
 538}
 539
 540static void set_cntvoff(u64 cntvoff)
 541{
 542	kvm_call_hyp(__kvm_timer_set_cntvoff, cntvoff);
 543}
 544
 545static 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
 552static 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
 573static 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
 601void 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
 631bool 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
 648void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
 649{
 650	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 651	struct timer_map map;
 652	struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
 653
 654	if (unlikely(!timer->enabled))
 655		return;
 656
 657	get_timer_map(vcpu, &map);
 658
 659	timer_save_state(map.direct_vtimer);
 660	if (map.direct_ptimer)
 661		timer_save_state(map.direct_ptimer);
 662
 663	/*
 664	 * Cancel soft timer emulation, because the only case where we
 665	 * need it after a vcpu_put is in the context of a sleeping VCPU, and
 666	 * in that case we already factor in the deadline for the physical
 667	 * timer when scheduling the bg_timer.
 668	 *
 669	 * In any case, we re-schedule the hrtimer for the physical timer when
 670	 * coming back to the VCPU thread in kvm_timer_vcpu_load().
 671	 */
 672	if (map.emul_ptimer)
 673		soft_timer_cancel(&map.emul_ptimer->hrtimer);
 674
 675	if (rcuwait_active(wait))
 676		kvm_timer_blocking(vcpu);
 677
 678	/*
 679	 * The kernel may decide to run userspace after calling vcpu_put, so
 680	 * we reset cntvoff to 0 to ensure a consistent read between user
 681	 * accesses to the virtual counter and kernel access to the physical
 682	 * counter of non-VHE case. For VHE, the virtual counter uses a fixed
 683	 * virtual offset of zero, so no need to zero CNTVOFF_EL2 register.
 684	 */
 685	set_cntvoff(0);
 686}
 687
 688/*
 689 * With a userspace irqchip we have to check if the guest de-asserted the
 690 * timer and if so, unmask the timer irq signal on the host interrupt
 691 * controller to ensure that we see future timer signals.
 692 */
 693static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu)
 694{
 695	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
 696
 697	if (!kvm_timer_should_fire(vtimer)) {
 698		kvm_timer_update_irq(vcpu, false, vtimer);
 699		if (static_branch_likely(&has_gic_active_state))
 700			set_timer_irq_phys_active(vtimer, false);
 701		else
 702			enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
 703	}
 704}
 705
 706void kvm_timer_sync_user(struct kvm_vcpu *vcpu)
 707{
 708	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 709
 710	if (unlikely(!timer->enabled))
 711		return;
 712
 713	if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
 714		unmask_vtimer_irq_user(vcpu);
 715}
 716
 717int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
 718{
 719	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 720	struct timer_map map;
 721
 722	get_timer_map(vcpu, &map);
 723
 724	/*
 725	 * The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8
 726	 * and to 0 for ARMv7.  We provide an implementation that always
 727	 * resets the timer to be disabled and unmasked and is compliant with
 728	 * the ARMv7 architecture.
 729	 */
 730	timer_set_ctl(vcpu_vtimer(vcpu), 0);
 731	timer_set_ctl(vcpu_ptimer(vcpu), 0);
 732
 733	if (timer->enabled) {
 734		kvm_timer_update_irq(vcpu, false, vcpu_vtimer(vcpu));
 735		kvm_timer_update_irq(vcpu, false, vcpu_ptimer(vcpu));
 736
 737		if (irqchip_in_kernel(vcpu->kvm)) {
 738			kvm_vgic_reset_mapped_irq(vcpu, map.direct_vtimer->irq.irq);
 739			if (map.direct_ptimer)
 740				kvm_vgic_reset_mapped_irq(vcpu, map.direct_ptimer->irq.irq);
 741		}
 742	}
 743
 744	if (map.emul_ptimer)
 745		soft_timer_cancel(&map.emul_ptimer->hrtimer);
 746
 747	return 0;
 748}
 749
 750/* Make the updates of cntvoff for all vtimer contexts atomic */
 751static void update_vtimer_cntvoff(struct kvm_vcpu *vcpu, u64 cntvoff)
 752{
 753	int i;
 754	struct kvm *kvm = vcpu->kvm;
 755	struct kvm_vcpu *tmp;
 756
 757	mutex_lock(&kvm->lock);
 758	kvm_for_each_vcpu(i, tmp, kvm)
 759		timer_set_offset(vcpu_vtimer(tmp), cntvoff);
 760
 761	/*
 762	 * When called from the vcpu create path, the CPU being created is not
 763	 * included in the loop above, so we just set it here as well.
 764	 */
 765	timer_set_offset(vcpu_vtimer(vcpu), cntvoff);
 766	mutex_unlock(&kvm->lock);
 767}
 768
 769void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
 770{
 771	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 772	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
 773	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
 774
 775	vtimer->vcpu = vcpu;
 776	ptimer->vcpu = vcpu;
 777
 778	/* Synchronize cntvoff across all vtimers of a VM. */
 779	update_vtimer_cntvoff(vcpu, kvm_phys_timer_read());
 780	timer_set_offset(ptimer, 0);
 781
 782	hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 783	timer->bg_timer.function = kvm_bg_timer_expire;
 784
 785	hrtimer_init(&vtimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 786	hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 787	vtimer->hrtimer.function = kvm_hrtimer_expire;
 788	ptimer->hrtimer.function = kvm_hrtimer_expire;
 789
 790	vtimer->irq.irq = default_vtimer_irq.irq;
 791	ptimer->irq.irq = default_ptimer_irq.irq;
 792
 793	vtimer->host_timer_irq = host_vtimer_irq;
 794	ptimer->host_timer_irq = host_ptimer_irq;
 795
 796	vtimer->host_timer_irq_flags = host_vtimer_irq_flags;
 797	ptimer->host_timer_irq_flags = host_ptimer_irq_flags;
 798}
 799
 800static void kvm_timer_init_interrupt(void *info)
 801{
 802	enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
 803	enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags);
 804}
 805
 806int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
 807{
 808	struct arch_timer_context *timer;
 809
 810	switch (regid) {
 811	case KVM_REG_ARM_TIMER_CTL:
 812		timer = vcpu_vtimer(vcpu);
 813		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
 814		break;
 815	case KVM_REG_ARM_TIMER_CNT:
 816		timer = vcpu_vtimer(vcpu);
 817		update_vtimer_cntvoff(vcpu, kvm_phys_timer_read() - value);
 818		break;
 819	case KVM_REG_ARM_TIMER_CVAL:
 820		timer = vcpu_vtimer(vcpu);
 821		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
 822		break;
 823	case KVM_REG_ARM_PTIMER_CTL:
 824		timer = vcpu_ptimer(vcpu);
 825		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
 826		break;
 827	case KVM_REG_ARM_PTIMER_CVAL:
 828		timer = vcpu_ptimer(vcpu);
 829		kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
 830		break;
 831
 832	default:
 833		return -1;
 834	}
 835
 836	return 0;
 837}
 838
 839static u64 read_timer_ctl(struct arch_timer_context *timer)
 840{
 841	/*
 842	 * Set ISTATUS bit if it's expired.
 843	 * Note that according to ARMv8 ARM Issue A.k, ISTATUS bit is
 844	 * UNKNOWN when ENABLE bit is 0, so we chose to set ISTATUS bit
 845	 * regardless of ENABLE bit for our implementation convenience.
 846	 */
 847	u32 ctl = timer_get_ctl(timer);
 848
 849	if (!kvm_timer_compute_delta(timer))
 850		ctl |= ARCH_TIMER_CTRL_IT_STAT;
 851
 852	return ctl;
 853}
 854
 855u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
 856{
 857	switch (regid) {
 858	case KVM_REG_ARM_TIMER_CTL:
 859		return kvm_arm_timer_read(vcpu,
 860					  vcpu_vtimer(vcpu), TIMER_REG_CTL);
 861	case KVM_REG_ARM_TIMER_CNT:
 862		return kvm_arm_timer_read(vcpu,
 863					  vcpu_vtimer(vcpu), TIMER_REG_CNT);
 864	case KVM_REG_ARM_TIMER_CVAL:
 865		return kvm_arm_timer_read(vcpu,
 866					  vcpu_vtimer(vcpu), TIMER_REG_CVAL);
 867	case KVM_REG_ARM_PTIMER_CTL:
 868		return kvm_arm_timer_read(vcpu,
 869					  vcpu_ptimer(vcpu), TIMER_REG_CTL);
 870	case KVM_REG_ARM_PTIMER_CNT:
 871		return kvm_arm_timer_read(vcpu,
 872					  vcpu_ptimer(vcpu), TIMER_REG_CNT);
 873	case KVM_REG_ARM_PTIMER_CVAL:
 874		return kvm_arm_timer_read(vcpu,
 875					  vcpu_ptimer(vcpu), TIMER_REG_CVAL);
 876	}
 877	return (u64)-1;
 878}
 879
 880static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
 881			      struct arch_timer_context *timer,
 882			      enum kvm_arch_timer_regs treg)
 883{
 884	u64 val;
 885
 886	switch (treg) {
 887	case TIMER_REG_TVAL:
 888		val = timer_get_cval(timer) - kvm_phys_timer_read() + timer_get_offset(timer);
 889		val = lower_32_bits(val);
 890		break;
 891
 892	case TIMER_REG_CTL:
 893		val = read_timer_ctl(timer);
 894		break;
 895
 896	case TIMER_REG_CVAL:
 897		val = timer_get_cval(timer);
 898		break;
 899
 900	case TIMER_REG_CNT:
 901		val = kvm_phys_timer_read() - timer_get_offset(timer);
 902		break;
 903
 904	default:
 905		BUG();
 906	}
 907
 908	return val;
 909}
 910
 911u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu,
 912			      enum kvm_arch_timers tmr,
 913			      enum kvm_arch_timer_regs treg)
 914{
 915	u64 val;
 916
 917	preempt_disable();
 918	kvm_timer_vcpu_put(vcpu);
 919
 920	val = kvm_arm_timer_read(vcpu, vcpu_get_timer(vcpu, tmr), treg);
 921
 922	kvm_timer_vcpu_load(vcpu);
 923	preempt_enable();
 924
 925	return val;
 926}
 927
 928static void kvm_arm_timer_write(struct kvm_vcpu *vcpu,
 929				struct arch_timer_context *timer,
 930				enum kvm_arch_timer_regs treg,
 931				u64 val)
 932{
 933	switch (treg) {
 934	case TIMER_REG_TVAL:
 935		timer_set_cval(timer, kvm_phys_timer_read() - timer_get_offset(timer) + (s32)val);
 936		break;
 937
 938	case TIMER_REG_CTL:
 939		timer_set_ctl(timer, val & ~ARCH_TIMER_CTRL_IT_STAT);
 940		break;
 941
 942	case TIMER_REG_CVAL:
 943		timer_set_cval(timer, val);
 944		break;
 945
 946	default:
 947		BUG();
 948	}
 949}
 950
 951void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu,
 952				enum kvm_arch_timers tmr,
 953				enum kvm_arch_timer_regs treg,
 954				u64 val)
 955{
 956	preempt_disable();
 957	kvm_timer_vcpu_put(vcpu);
 958
 959	kvm_arm_timer_write(vcpu, vcpu_get_timer(vcpu, tmr), treg, val);
 960
 961	kvm_timer_vcpu_load(vcpu);
 962	preempt_enable();
 963}
 964
 965static int kvm_timer_starting_cpu(unsigned int cpu)
 966{
 967	kvm_timer_init_interrupt(NULL);
 968	return 0;
 969}
 970
 971static int kvm_timer_dying_cpu(unsigned int cpu)
 972{
 973	disable_percpu_irq(host_vtimer_irq);
 974	return 0;
 975}
 976
 977static int timer_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
 978{
 979	if (vcpu)
 980		irqd_set_forwarded_to_vcpu(d);
 981	else
 982		irqd_clr_forwarded_to_vcpu(d);
 983
 984	return 0;
 985}
 986
 987static int timer_irq_set_irqchip_state(struct irq_data *d,
 988				       enum irqchip_irq_state which, bool val)
 989{
 990	if (which != IRQCHIP_STATE_ACTIVE || !irqd_is_forwarded_to_vcpu(d))
 991		return irq_chip_set_parent_state(d, which, val);
 992
 993	if (val)
 994		irq_chip_mask_parent(d);
 995	else
 996		irq_chip_unmask_parent(d);
 997
 998	return 0;
 999}
1000
1001static void timer_irq_eoi(struct irq_data *d)
1002{
1003	if (!irqd_is_forwarded_to_vcpu(d))
1004		irq_chip_eoi_parent(d);
1005}
1006
1007static void timer_irq_ack(struct irq_data *d)
1008{
1009	d = d->parent_data;
1010	if (d->chip->irq_ack)
1011		d->chip->irq_ack(d);
1012}
1013
1014static struct irq_chip timer_chip = {
1015	.name			= "KVM",
1016	.irq_ack		= timer_irq_ack,
1017	.irq_mask		= irq_chip_mask_parent,
1018	.irq_unmask		= irq_chip_unmask_parent,
1019	.irq_eoi		= timer_irq_eoi,
1020	.irq_set_type		= irq_chip_set_type_parent,
1021	.irq_set_vcpu_affinity	= timer_irq_set_vcpu_affinity,
1022	.irq_set_irqchip_state	= timer_irq_set_irqchip_state,
1023};
1024
1025static int timer_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
1026				  unsigned int nr_irqs, void *arg)
1027{
1028	irq_hw_number_t hwirq = (uintptr_t)arg;
1029
1030	return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
1031					     &timer_chip, NULL);
1032}
1033
1034static void timer_irq_domain_free(struct irq_domain *domain, unsigned int virq,
1035				  unsigned int nr_irqs)
1036{
1037}
1038
1039static const struct irq_domain_ops timer_domain_ops = {
1040	.alloc	= timer_irq_domain_alloc,
1041	.free	= timer_irq_domain_free,
1042};
1043
1044static struct irq_ops arch_timer_irq_ops = {
1045	.get_input_level = kvm_arch_timer_get_input_level,
1046};
1047
1048static void kvm_irq_fixup_flags(unsigned int virq, u32 *flags)
1049{
1050	*flags = irq_get_trigger_type(virq);
1051	if (*flags != IRQF_TRIGGER_HIGH && *flags != IRQF_TRIGGER_LOW) {
1052		kvm_err("Invalid trigger for timer IRQ%d, assuming level low\n",
1053			virq);
1054		*flags = IRQF_TRIGGER_LOW;
1055	}
1056}
1057
1058static int kvm_irq_init(struct arch_timer_kvm_info *info)
1059{
1060	struct irq_domain *domain = NULL;
1061
1062	if (info->virtual_irq <= 0) {
1063		kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n",
1064			info->virtual_irq);
1065		return -ENODEV;
1066	}
1067
1068	host_vtimer_irq = info->virtual_irq;
1069	kvm_irq_fixup_flags(host_vtimer_irq, &host_vtimer_irq_flags);
1070
1071	if (kvm_vgic_global_state.no_hw_deactivation) {
1072		struct fwnode_handle *fwnode;
1073		struct irq_data *data;
1074
1075		fwnode = irq_domain_alloc_named_fwnode("kvm-timer");
1076		if (!fwnode)
1077			return -ENOMEM;
1078
1079		/* Assume both vtimer and ptimer in the same parent */
1080		data = irq_get_irq_data(host_vtimer_irq);
1081		domain = irq_domain_create_hierarchy(data->domain, 0,
1082						     NR_KVM_TIMERS, fwnode,
1083						     &timer_domain_ops, NULL);
1084		if (!domain) {
1085			irq_domain_free_fwnode(fwnode);
1086			return -ENOMEM;
1087		}
1088
1089		arch_timer_irq_ops.flags |= VGIC_IRQ_SW_RESAMPLE;
1090		WARN_ON(irq_domain_push_irq(domain, host_vtimer_irq,
1091					    (void *)TIMER_VTIMER));
1092	}
1093
1094	if (info->physical_irq > 0) {
1095		host_ptimer_irq = info->physical_irq;
1096		kvm_irq_fixup_flags(host_ptimer_irq, &host_ptimer_irq_flags);
1097
1098		if (domain)
1099			WARN_ON(irq_domain_push_irq(domain, host_ptimer_irq,
1100						    (void *)TIMER_PTIMER));
1101	}
1102
1103	return 0;
1104}
1105
1106int kvm_timer_hyp_init(bool has_gic)
1107{
1108	struct arch_timer_kvm_info *info;
1109	int err;
1110
1111	info = arch_timer_get_kvm_info();
1112	timecounter = &info->timecounter;
1113
1114	if (!timecounter->cc) {
1115		kvm_err("kvm_arch_timer: uninitialized timecounter\n");
1116		return -ENODEV;
1117	}
1118
1119	err = kvm_irq_init(info);
1120	if (err)
1121		return err;
1122
1123	/* First, do the virtual EL1 timer irq */
1124
1125	err = request_percpu_irq(host_vtimer_irq, kvm_arch_timer_handler,
1126				 "kvm guest vtimer", kvm_get_running_vcpus());
1127	if (err) {
1128		kvm_err("kvm_arch_timer: can't request vtimer interrupt %d (%d)\n",
1129			host_vtimer_irq, err);
1130		return err;
1131	}
1132
1133	if (has_gic) {
1134		err = irq_set_vcpu_affinity(host_vtimer_irq,
1135					    kvm_get_running_vcpus());
1136		if (err) {
1137			kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
1138			goto out_free_irq;
1139		}
1140
1141		static_branch_enable(&has_gic_active_state);
1142	}
1143
1144	kvm_debug("virtual timer IRQ%d\n", host_vtimer_irq);
1145
1146	/* Now let's do the physical EL1 timer irq */
1147
1148	if (info->physical_irq > 0) {
1149		err = request_percpu_irq(host_ptimer_irq, kvm_arch_timer_handler,
1150					 "kvm guest ptimer", kvm_get_running_vcpus());
1151		if (err) {
1152			kvm_err("kvm_arch_timer: can't request ptimer interrupt %d (%d)\n",
1153				host_ptimer_irq, err);
1154			return err;
1155		}
1156
1157		if (has_gic) {
1158			err = irq_set_vcpu_affinity(host_ptimer_irq,
1159						    kvm_get_running_vcpus());
1160			if (err) {
1161				kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
1162				goto out_free_irq;
1163			}
1164		}
1165
1166		kvm_debug("physical timer IRQ%d\n", host_ptimer_irq);
1167	} else if (has_vhe()) {
1168		kvm_err("kvm_arch_timer: invalid physical timer IRQ: %d\n",
1169			info->physical_irq);
1170		err = -ENODEV;
1171		goto out_free_irq;
1172	}
1173
1174	cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING,
1175			  "kvm/arm/timer:starting", kvm_timer_starting_cpu,
1176			  kvm_timer_dying_cpu);
1177	return 0;
1178out_free_irq:
1179	free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus());
1180	return err;
1181}
1182
1183void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
1184{
1185	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1186
1187	soft_timer_cancel(&timer->bg_timer);
1188}
1189
1190static bool timer_irqs_are_valid(struct kvm_vcpu *vcpu)
1191{
1192	int vtimer_irq, ptimer_irq;
1193	int i, ret;
1194
1195	vtimer_irq = vcpu_vtimer(vcpu)->irq.irq;
1196	ret = kvm_vgic_set_owner(vcpu, vtimer_irq, vcpu_vtimer(vcpu));
1197	if (ret)
1198		return false;
1199
1200	ptimer_irq = vcpu_ptimer(vcpu)->irq.irq;
1201	ret = kvm_vgic_set_owner(vcpu, ptimer_irq, vcpu_ptimer(vcpu));
1202	if (ret)
1203		return false;
1204
1205	kvm_for_each_vcpu(i, vcpu, vcpu->kvm) {
1206		if (vcpu_vtimer(vcpu)->irq.irq != vtimer_irq ||
1207		    vcpu_ptimer(vcpu)->irq.irq != ptimer_irq)
1208			return false;
1209	}
1210
1211	return true;
1212}
1213
1214bool kvm_arch_timer_get_input_level(int vintid)
1215{
1216	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
1217	struct arch_timer_context *timer;
1218
1219	if (vintid == vcpu_vtimer(vcpu)->irq.irq)
1220		timer = vcpu_vtimer(vcpu);
1221	else if (vintid == vcpu_ptimer(vcpu)->irq.irq)
1222		timer = vcpu_ptimer(vcpu);
1223	else
1224		BUG();
1225
1226	return kvm_timer_should_fire(timer);
1227}
1228
1229int kvm_timer_enable(struct kvm_vcpu *vcpu)
1230{
1231	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1232	struct timer_map map;
1233	int ret;
1234
1235	if (timer->enabled)
1236		return 0;
1237
1238	/* Without a VGIC we do not map virtual IRQs to physical IRQs */
1239	if (!irqchip_in_kernel(vcpu->kvm))
1240		goto no_vgic;
1241
1242	/*
1243	 * At this stage, we have the guarantee that the vgic is both
1244	 * available and initialized.
1245	 */
1246	if (!timer_irqs_are_valid(vcpu)) {
1247		kvm_debug("incorrectly configured timer irqs\n");
1248		return -EINVAL;
1249	}
1250
1251	get_timer_map(vcpu, &map);
1252
1253	ret = kvm_vgic_map_phys_irq(vcpu,
1254				    map.direct_vtimer->host_timer_irq,
1255				    map.direct_vtimer->irq.irq,
1256				    &arch_timer_irq_ops);
1257	if (ret)
1258		return ret;
1259
1260	if (map.direct_ptimer) {
1261		ret = kvm_vgic_map_phys_irq(vcpu,
1262					    map.direct_ptimer->host_timer_irq,
1263					    map.direct_ptimer->irq.irq,
1264					    &arch_timer_irq_ops);
1265	}
1266
1267	if (ret)
1268		return ret;
1269
1270no_vgic:
1271	timer->enabled = 1;
1272	return 0;
1273}
1274
1275/*
1276 * On VHE system, we only need to configure the EL2 timer trap register once,
1277 * not for every world switch.
1278 * The host kernel runs at EL2 with HCR_EL2.TGE == 1,
1279 * and this makes those bits have no effect for the host kernel execution.
1280 */
1281void kvm_timer_init_vhe(void)
1282{
1283	/* When HCR_EL2.E2H ==1, EL1PCEN and EL1PCTEN are shifted by 10 */
1284	u32 cnthctl_shift = 10;
1285	u64 val;
1286
1287	/*
1288	 * VHE systems allow the guest direct access to the EL1 physical
1289	 * timer/counter.
1290	 */
1291	val = read_sysreg(cnthctl_el2);
1292	val |= (CNTHCTL_EL1PCEN << cnthctl_shift);
1293	val |= (CNTHCTL_EL1PCTEN << cnthctl_shift);
1294	write_sysreg(val, cnthctl_el2);
1295}
1296
1297static void set_timer_irqs(struct kvm *kvm, int vtimer_irq, int ptimer_irq)
1298{
1299	struct kvm_vcpu *vcpu;
1300	int i;
1301
1302	kvm_for_each_vcpu(i, vcpu, kvm) {
1303		vcpu_vtimer(vcpu)->irq.irq = vtimer_irq;
1304		vcpu_ptimer(vcpu)->irq.irq = ptimer_irq;
1305	}
1306}
1307
1308int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1309{
1310	int __user *uaddr = (int __user *)(long)attr->addr;
1311	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
1312	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
1313	int irq;
1314
1315	if (!irqchip_in_kernel(vcpu->kvm))
1316		return -EINVAL;
1317
1318	if (get_user(irq, uaddr))
1319		return -EFAULT;
1320
1321	if (!(irq_is_ppi(irq)))
1322		return -EINVAL;
1323
1324	if (vcpu->arch.timer_cpu.enabled)
1325		return -EBUSY;
1326
1327	switch (attr->attr) {
1328	case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1329		set_timer_irqs(vcpu->kvm, irq, ptimer->irq.irq);
1330		break;
1331	case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1332		set_timer_irqs(vcpu->kvm, vtimer->irq.irq, irq);
1333		break;
1334	default:
1335		return -ENXIO;
1336	}
1337
1338	return 0;
1339}
1340
1341int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1342{
1343	int __user *uaddr = (int __user *)(long)attr->addr;
1344	struct arch_timer_context *timer;
1345	int irq;
1346
1347	switch (attr->attr) {
1348	case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1349		timer = vcpu_vtimer(vcpu);
1350		break;
1351	case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1352		timer = vcpu_ptimer(vcpu);
1353		break;
1354	default:
1355		return -ENXIO;
1356	}
1357
1358	irq = timer->irq.irq;
1359	return put_user(irq, uaddr);
1360}
1361
1362int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1363{
1364	switch (attr->attr) {
1365	case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1366	case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1367		return 0;
1368	}
1369
1370	return -ENXIO;
1371}