[linux-2.6-block.git] / virt / kvm / arm / arch_timer.c

/*
 * Copyright (C) 2012 ARM Ltd.
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/cpu.h>
#include <linux/of_irq.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/interrupt.h>

#include <clocksource/arm_arch_timer.h>
#include <asm/arch_timer.h>

#include <kvm/arm_vgic.h>
#include <kvm/arm_arch_timer.h>

static struct timecounter *timecounter;
static struct workqueue_struct *wqueue;
static unsigned int host_vtimer_irq;

static cycle_t kvm_phys_timer_read(void)
{
	return timecounter->cc->read(timecounter->cc);
}

static bool timer_is_armed(struct arch_timer_cpu *timer)
{
	return timer->armed;
}

/* timer_arm: as in "arm the timer", not as in ARM the company */
static void timer_arm(struct arch_timer_cpu *timer, u64 ns)
{
	timer->armed = true;
	hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns),
		      HRTIMER_MODE_ABS);
}

static void timer_disarm(struct arch_timer_cpu *timer)
{
	if (timer_is_armed(timer)) {
		hrtimer_cancel(&timer->timer);
		cancel_work_sync(&timer->expired);
		timer->armed = false;
	}
}

static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu)
{
	int ret;
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	timer->cntv_ctl |= ARCH_TIMER_CTRL_IT_MASK;
	ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
				  timer->irq->irq,
				  timer->irq->level);
	WARN_ON(ret);
}

static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
{
	struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id;

	/*
	 * We disable the timer in the world switch and let it be
	 * handled by kvm_timer_sync_hwstate(). Getting a timer
	 * interrupt at this point is a sure sign of some major
	 * breakage.
	 */
	pr_warn("Unexpected interrupt %d on vcpu %p\n", irq, vcpu);
	return IRQ_HANDLED;
}

/*
 * Work function for handling the backup timer that we schedule when a vcpu is
 * no longer running, but had a timer programmed to fire in the future.
 */
static void kvm_timer_inject_irq_work(struct work_struct *work)
{
	struct kvm_vcpu *vcpu;

	vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired);
	vcpu->arch.timer_cpu.armed = false;

	/*
	 * If the vcpu is blocked we want to wake it up so that it will see
	 * the timer has expired when entering the guest.
	 */
	kvm_vcpu_kick(vcpu);
}

static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt)
{
	struct arch_timer_cpu *timer;
	timer = container_of(hrt, struct arch_timer_cpu, timer);
	queue_work(wqueue, &timer->expired);
	return HRTIMER_NORESTART;
}

bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	cycle_t cval, now;

	if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) ||
		!(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE))
		return false;

	cval = timer->cntv_cval;
	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;

	return cval <= now;
}

/**
 * kvm_timer_flush_hwstate - prepare to move the virt timer to the cpu
 * @vcpu: The vcpu pointer
 *
 * Disarm any pending soft timers, since the world-switch code will write the
 * virtual timer state back to the physical CPU.
 */
void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	/*
	 * We're about to run this vcpu again, so there is no need to
	 * keep the background timer running, as we're about to
	 * populate the CPU timer again.
	 */
	timer_disarm(timer);

	/*
	 * If the timer expired while we were not scheduled, now is the time
	 * to inject it.
	 */
	if (kvm_timer_should_fire(vcpu))
		kvm_timer_inject_irq(vcpu);
}

/**
 * kvm_timer_sync_hwstate - sync timer state from cpu
 * @vcpu: The vcpu pointer
 *
 * Check if the virtual timer was armed and either schedule a corresponding
 * soft timer or inject directly if already expired.
 */
void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	cycle_t cval, now;
	u64 ns;

	BUG_ON(timer_is_armed(timer));

	if (kvm_timer_should_fire(vcpu)) {
		/*
		 * Timer has already expired while we were not
		 * looking. Inject the interrupt and carry on.
		 */
		kvm_timer_inject_irq(vcpu);
		return;
	}

	cval = timer->cntv_cval;
	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;

	ns = cyclecounter_cyc2ns(timecounter->cc, cval - now, timecounter->mask,
				 &timecounter->frac);
	timer_arm(timer, ns);
}

void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
			  const struct kvm_irq_level *irq)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	/*
	 * The vcpu timer irq number cannot be determined in
	 * kvm_timer_vcpu_init() because it is called much before
	 * kvm_vcpu_set_target(). To handle this, we determine
	 * vcpu timer irq number when the vcpu is reset.
	 */
	timer->irq = irq;
}

void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	INIT_WORK(&timer->expired, kvm_timer_inject_irq_work);
	hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
	timer->timer.function = kvm_timer_expire;
}

static void kvm_timer_init_interrupt(void *info)
{
	enable_percpu_irq(host_vtimer_irq, 0);
}

int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	switch (regid) {
	case KVM_REG_ARM_TIMER_CTL:
		timer->cntv_ctl = value;
		break;
	case KVM_REG_ARM_TIMER_CNT:
		vcpu->kvm->arch.timer.cntvoff = kvm_phys_timer_read() - value;
		break;
	case KVM_REG_ARM_TIMER_CVAL:
		timer->cntv_cval = value;
		break;
	default:
		return -1;
	}
	return 0;
}

u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	switch (regid) {
	case KVM_REG_ARM_TIMER_CTL:
		return timer->cntv_ctl;
	case KVM_REG_ARM_TIMER_CNT:
		return kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
	case KVM_REG_ARM_TIMER_CVAL:
		return timer->cntv_cval;
	}
	return (u64)-1;
}

static int kvm_timer_cpu_notify(struct notifier_block *self,
				unsigned long action, void *cpu)
{
	switch (action) {
	case CPU_STARTING:
	case CPU_STARTING_FROZEN:
		kvm_timer_init_interrupt(NULL);
		break;
	case CPU_DYING:
	case CPU_DYING_FROZEN:
		disable_percpu_irq(host_vtimer_irq);
		break;
	}

	return NOTIFY_OK;
}

static struct notifier_block kvm_timer_cpu_nb = {
	.notifier_call = kvm_timer_cpu_notify,
};

static const struct of_device_id arch_timer_of_match[] = {
	{ .compatible	= "arm,armv7-timer",	},
	{ .compatible	= "arm,armv8-timer",	},
	{},
};

int kvm_timer_hyp_init(void)
{
	struct device_node *np;
	unsigned int ppi;
	int err;

	timecounter = arch_timer_get_timecounter();
	if (!timecounter)
		return -ENODEV;

	np = of_find_matching_node(NULL, arch_timer_of_match);
	if (!np) {
		kvm_err("kvm_arch_timer: can't find DT node\n");
		return -ENODEV;
	}

	ppi = irq_of_parse_and_map(np, 2);
	if (!ppi) {
		kvm_err("kvm_arch_timer: no virtual timer interrupt\n");
		err = -EINVAL;
		goto out;
	}

	err = request_percpu_irq(ppi, kvm_arch_timer_handler,
				 "kvm guest timer", kvm_get_running_vcpus());
	if (err) {
		kvm_err("kvm_arch_timer: can't request interrupt %d (%d)\n",
			ppi, err);
		goto out;
	}

	host_vtimer_irq = ppi;

	err = __register_cpu_notifier(&kvm_timer_cpu_nb);
	if (err) {
		kvm_err("Cannot register timer CPU notifier\n");
		goto out_free;
	}

	wqueue = create_singlethread_workqueue("kvm_arch_timer");
	if (!wqueue) {
		err = -ENOMEM;
		goto out_free;
	}

	kvm_info("%s IRQ%d\n", np->name, ppi);
	on_each_cpu(kvm_timer_init_interrupt, NULL, 1);

	goto out;
out_free:
	free_percpu_irq(ppi, kvm_get_running_vcpus());
out:
	of_node_put(np);
	return err;
}

void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	timer_disarm(timer);
}

void kvm_timer_enable(struct kvm *kvm)
{
	if (kvm->arch.timer.enabled)
		return;

	/*
	 * There is a potential race here between VCPUs starting for the first
	 * time, which may be enabling the timer multiple times.  That doesn't
	 * hurt though, because we're just setting a variable to the same
	 * variable that it already was.  The important thing is that all
	 * VCPUs have the enabled variable set, before entering the guest, if
	 * the arch timers are enabled.
	 */
	if (timecounter && wqueue)
		kvm->arch.timer.enabled = 1;
}

void kvm_timer_init(struct kvm *kvm)
{
	kvm->arch.timer.cntvoff = kvm_phys_timer_read();
}
Commit	Line	Data
53e72406 MZ	1	/*
	2	* Copyright (C) 2012 ARM Ltd.
	3	* Author: Marc Zyngier <marc.zyngier@arm.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	17	*/
	18
	19	#include <linux/cpu.h>
	20	#include <linux/of_irq.h>
	21	#include <linux/kvm.h>
	22	#include <linux/kvm_host.h>
	23	#include <linux/interrupt.h>
	24
372b7c1b	25	#include <clocksource/arm_arch_timer.h>
53e72406 MZ	26	#include <asm/arch_timer.h>
53e72406 MZ	27
7275acdf MZ	28	#include <kvm/arm_vgic.h>
7275acdf MZ	29	#include <kvm/arm_arch_timer.h>
53e72406 MZ	30
	31	static struct timecounter *timecounter;
	32	static struct workqueue_struct *wqueue;
5ae7f87a	33	static unsigned int host_vtimer_irq;
53e72406 MZ	34
	35	static cycle_t kvm_phys_timer_read(void)
	36	{
	37	return timecounter->cc->read(timecounter->cc);
	38	}
	39
	40	static bool timer_is_armed(struct arch_timer_cpu *timer)
	41	{
	42	return timer->armed;
	43	}
	44
	45	/* timer_arm: as in "arm the timer", not as in ARM the company */
	46	static void timer_arm(struct arch_timer_cpu *timer, u64 ns)
	47	{
	48	timer->armed = true;
	49	hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns),
	50	HRTIMER_MODE_ABS);
	51	}
	52
	53	static void timer_disarm(struct arch_timer_cpu *timer)
	54	{
	55	if (timer_is_armed(timer)) {
	56	hrtimer_cancel(&timer->timer);
	57	cancel_work_sync(&timer->expired);
	58	timer->armed = false;
	59	}
	60	}
	61
	62	static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu)
	63	{
05971120	64	int ret;
53e72406 MZ	65	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
53e72406 MZ	66
372b7c1b	67	timer->cntv_ctl \|= ARCH_TIMER_CTRL_IT_MASK;
05971120 CD	68	ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
	69	timer->irq->irq,
	70	timer->irq->level);
	71	WARN_ON(ret);
53e72406 MZ	72	}
	73
	74	static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
	75	{
	76	struct kvm_vcpu vcpu = (struct kvm_vcpu **)dev_id;
	77
	78	/*
	79	* We disable the timer in the world switch and let it be
	80	* handled by kvm_timer_sync_hwstate(). Getting a timer
	81	* interrupt at this point is a sure sign of some major
	82	* breakage.
	83	*/
	84	pr_warn("Unexpected interrupt %d on vcpu %p\n", irq, vcpu);
	85	return IRQ_HANDLED;
	86	}
	87
1a748478 CD	88	/*
	89	* Work function for handling the backup timer that we schedule when a vcpu is
	90	* no longer running, but had a timer programmed to fire in the future.
	91	*/
53e72406 MZ	92	static void kvm_timer_inject_irq_work(struct work_struct *work)
	93	{
	94	struct kvm_vcpu *vcpu;
	95
	96	vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired);
	97	vcpu->arch.timer_cpu.armed = false;
1a748478 CD	98
	99	/*
	100	* If the vcpu is blocked we want to wake it up so that it will see
	101	* the timer has expired when entering the guest.
	102	*/
	103	kvm_vcpu_kick(vcpu);
53e72406 MZ	104	}
	105
	106	static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt)
	107	{
	108	struct arch_timer_cpu *timer;
	109	timer = container_of(hrt, struct arch_timer_cpu, timer);
	110	queue_work(wqueue, &timer->expired);
	111	return HRTIMER_NORESTART;
	112	}
	113
1a748478 CD	114	bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
	115	{
	116	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	117	cycle_t cval, now;
	118
	119	if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) \|\|
	120	!(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE))
	121	return false;
	122
	123	cval = timer->cntv_cval;
	124	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
	125
	126	return cval <= now;
	127	}
	128
53e72406 MZ	129	/**
	130	* kvm_timer_flush_hwstate - prepare to move the virt timer to the cpu
	131	* @vcpu: The vcpu pointer
	132	*
	133	* Disarm any pending soft timers, since the world-switch code will write the
	134	* virtual timer state back to the physical CPU.
	135	*/
	136	void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
	137	{
	138	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	139
	140	/*
	141	* We're about to run this vcpu again, so there is no need to
	142	* keep the background timer running, as we're about to
	143	* populate the CPU timer again.
	144	*/
	145	timer_disarm(timer);
1a748478 CD	146
	147	/*
	148	* If the timer expired while we were not scheduled, now is the time
	149	* to inject it.
	150	*/
	151	if (kvm_timer_should_fire(vcpu))
	152	kvm_timer_inject_irq(vcpu);
53e72406 MZ	153	}
	154
	155	/**
	156	* kvm_timer_sync_hwstate - sync timer state from cpu
	157	* @vcpu: The vcpu pointer
	158	*
	159	* Check if the virtual timer was armed and either schedule a corresponding
	160	* soft timer or inject directly if already expired.
	161	*/
	162	void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
	163	{
	164	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	165	cycle_t cval, now;
	166	u64 ns;
	167
53e72406 MZ	168	BUG_ON(timer_is_armed(timer));
53e72406 MZ	169
1a748478	170	if (kvm_timer_should_fire(vcpu)) {
53e72406 MZ	171	/*
	172	* Timer has already expired while we were not
	173	* looking. Inject the interrupt and carry on.
	174	*/
	175	kvm_timer_inject_irq(vcpu);
	176	return;
	177	}
	178
1a748478 CD	179	cval = timer->cntv_cval;
	180	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
	181
2eebdde6 RC	182	ns = cyclecounter_cyc2ns(timecounter->cc, cval - now, timecounter->mask,
2eebdde6 RC	183	&timecounter->frac);
53e72406 MZ	184	timer_arm(timer, ns);
	185	}
	186
5ae7f87a AP	187	void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
	188	const struct kvm_irq_level *irq)
	189	{
	190	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	191
	192	/*
	193	* The vcpu timer irq number cannot be determined in
	194	* kvm_timer_vcpu_init() because it is called much before
	195	* kvm_vcpu_set_target(). To handle this, we determine
	196	* vcpu timer irq number when the vcpu is reset.
	197	*/
	198	timer->irq = irq;
	199	}
	200
53e72406 MZ	201	void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
	202	{
	203	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	204
	205	INIT_WORK(&timer->expired, kvm_timer_inject_irq_work);
	206	hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
	207	timer->timer.function = kvm_timer_expire;
53e72406 MZ	208	}
	209
	210	static void kvm_timer_init_interrupt(void *info)
	211	{
5ae7f87a	212	enable_percpu_irq(host_vtimer_irq, 0);
53e72406 MZ	213	}
53e72406 MZ	214
39735a3a AP	215	int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
	216	{
	217	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	218
	219	switch (regid) {
	220	case KVM_REG_ARM_TIMER_CTL:
	221	timer->cntv_ctl = value;
	222	break;
	223	case KVM_REG_ARM_TIMER_CNT:
	224	vcpu->kvm->arch.timer.cntvoff = kvm_phys_timer_read() - value;
	225	break;
	226	case KVM_REG_ARM_TIMER_CVAL:
	227	timer->cntv_cval = value;
	228	break;
	229	default:
	230	return -1;
	231	}
	232	return 0;
	233	}
	234
	235	u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
	236	{
	237	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	238
	239	switch (regid) {
	240	case KVM_REG_ARM_TIMER_CTL:
	241	return timer->cntv_ctl;
	242	case KVM_REG_ARM_TIMER_CNT:
	243	return kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
	244	case KVM_REG_ARM_TIMER_CVAL:
	245	return timer->cntv_cval;
	246	}
	247	return (u64)-1;
	248	}
53e72406 MZ	249
	250	static int kvm_timer_cpu_notify(struct notifier_block *self,
	251	unsigned long action, void *cpu)
	252	{
	253	switch (action) {
	254	case CPU_STARTING:
	255	case CPU_STARTING_FROZEN:
	256	kvm_timer_init_interrupt(NULL);
	257	break;
	258	case CPU_DYING:
	259	case CPU_DYING_FROZEN:
5ae7f87a	260	disable_percpu_irq(host_vtimer_irq);
53e72406 MZ	261	break;
	262	}
	263
	264	return NOTIFY_OK;
	265	}
	266
	267	static struct notifier_block kvm_timer_cpu_nb = {
	268	.notifier_call = kvm_timer_cpu_notify,
	269	};
	270
	271	static const struct of_device_id arch_timer_of_match[] = {
	272	{ .compatible = "arm,armv7-timer", },
f61701e0	273	{ .compatible = "arm,armv8-timer", },
53e72406 MZ	274	{},
	275	};
	276
	277	int kvm_timer_hyp_init(void)
	278	{
	279	struct device_node *np;
	280	unsigned int ppi;
	281	int err;
	282
	283	timecounter = arch_timer_get_timecounter();
	284	if (!timecounter)
	285	return -ENODEV;
	286
	287	np = of_find_matching_node(NULL, arch_timer_of_match);
	288	if (!np) {
	289	kvm_err("kvm_arch_timer: can't find DT node\n");
	290	return -ENODEV;
	291	}
	292
	293	ppi = irq_of_parse_and_map(np, 2);
	294	if (!ppi) {
	295	kvm_err("kvm_arch_timer: no virtual timer interrupt\n");
	296	err = -EINVAL;
	297	goto out;
	298	}
	299
	300	err = request_percpu_irq(ppi, kvm_arch_timer_handler,
	301	"kvm guest timer", kvm_get_running_vcpus());
	302	if (err) {
	303	kvm_err("kvm_arch_timer: can't request interrupt %d (%d)\n",
	304	ppi, err);
	305	goto out;
	306	}
	307
5ae7f87a	308	host_vtimer_irq = ppi;
53e72406	309
553f809e	310	err = __register_cpu_notifier(&kvm_timer_cpu_nb);
53e72406 MZ	311	if (err) {
	312	kvm_err("Cannot register timer CPU notifier\n");
	313	goto out_free;
	314	}
	315
	316	wqueue = create_singlethread_workqueue("kvm_arch_timer");
	317	if (!wqueue) {
	318	err = -ENOMEM;
	319	goto out_free;
	320	}
	321
	322	kvm_info("%s IRQ%d\n", np->name, ppi);
	323	on_each_cpu(kvm_timer_init_interrupt, NULL, 1);
	324
	325	goto out;
	326	out_free:
	327	free_percpu_irq(ppi, kvm_get_running_vcpus());
	328	out:
	329	of_node_put(np);
	330	return err;
	331	}
	332
	333	void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
	334	{
	335	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	336
	337	timer_disarm(timer);
	338	}
	339
05971120	340	void kvm_timer_enable(struct kvm *kvm)
53e72406	341	{
05971120 CD	342	if (kvm->arch.timer.enabled)
	343	return;
	344
	345	/*
	346	* There is a potential race here between VCPUs starting for the first
	347	* time, which may be enabling the timer multiple times. That doesn't
	348	* hurt though, because we're just setting a variable to the same
	349	* variable that it already was. The important thing is that all
	350	* VCPUs have the enabled variable set, before entering the guest, if
	351	* the arch timers are enabled.
	352	*/
	353	if (timecounter && wqueue)
53e72406	354	kvm->arch.timer.enabled = 1;
05971120	355	}
53e72406	356
05971120 CD	357	void kvm_timer_init(struct kvm *kvm)
	358	{
	359	kvm->arch.timer.cntvoff = kvm_phys_timer_read();
53e72406	360	}