[mirror_ubuntu-eoan-kernel.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;

	kvm_vgic_set_phys_irq_active(timer->map, true);
	ret = kvm_vgic_inject_mapped_irq(vcpu->kvm, vcpu->vcpu_id,
					 timer->map,
					 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;
}

static bool kvm_timer_irq_can_fire(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	return !(timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) &&
		(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE) &&
		!kvm_vgic_get_phys_irq_active(timer->map);
}

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

	if (!kvm_timer_irq_can_fire(vcpu))
		return false;

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

	return cval <= now;
}

/*
 * Schedule the background timer before calling kvm_vcpu_block, so that this
 * thread is removed from its waitqueue and made runnable when there's a timer
 * interrupt to handle.
 */
void kvm_timer_schedule(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	u64 ns;
	cycle_t cval, now;

	BUG_ON(timer_is_armed(timer));

	/*
	 * No need to schedule a background timer if the guest timer has
	 * already expired, because kvm_vcpu_block will return before putting
	 * the thread to sleep.
	 */
	if (kvm_timer_should_fire(vcpu))
		return;

	/*
	 * If the timer is not capable of raising interrupts (disabled or
	 * masked), then there's no more work for us to do.
	 */
	if (!kvm_timer_irq_can_fire(vcpu))
		return;

	/*  The timer has not yet expired, schedule a background timer */
	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_unschedule(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	timer_disarm(timer);
}

/**
 * kvm_timer_flush_hwstate - prepare to move the virt timer to the cpu
 * @vcpu: The vcpu pointer
 *
 * Check if the virtual timer has expired while we were running in the host,
 * and inject an interrupt if that was the case.
 */
void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	bool phys_active;
	int ret;

	if (kvm_timer_should_fire(vcpu))
		kvm_timer_inject_irq(vcpu);

	/*
	 * We keep track of whether the edge-triggered interrupt has been
	 * signalled to the vgic/guest, and if so, we mask the interrupt and
	 * the physical distributor to prevent the timer from raising a
	 * physical interrupt whenever we run a guest, preventing forward
	 * VCPU progress.
	 */
	if (kvm_vgic_get_phys_irq_active(timer->map))
		phys_active = true;
	else
		phys_active = false;

	ret = irq_set_irqchip_state(timer->map->irq,
				    IRQCHIP_STATE_ACTIVE,
				    phys_active);
	WARN_ON(ret);
}

/**
 * kvm_timer_sync_hwstate - sync timer state from cpu
 * @vcpu: The vcpu pointer
 *
 * Check if the virtual timer has expired while we were running in the guest,
 * and inject an interrupt if that was the case.
 */
void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
{
	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	BUG_ON(timer_is_armed(timer));

	if (kvm_timer_should_fire(vcpu))
		kvm_timer_inject_irq(vcpu);
}

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

	/*
	 * 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;

	/*
	 * The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8
	 * and to 0 for ARMv7.  We provide an implementation that always
	 * resets the timer to be disabled and unmasked and is compliant with
	 * the ARMv7 architecture.
	 */
	timer->cntv_ctl = 0;

	/*
	 * Tell the VGIC that the virtual interrupt is tied to a
	 * physical interrupt. We do that once per VCPU.
	 */
	map = kvm_vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
	if (WARN_ON(IS_ERR(map)))
		return PTR_ERR(map);

	timer->map = map;
	return 0;
}

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);
	if (timer->map)
		kvm_vgic_unmap_phys_irq(vcpu, timer->map);
}

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
f120cd65 MZ	67	kvm_vgic_set_phys_irq_active(timer->map, true);
	68	ret = kvm_vgic_inject_mapped_irq(vcpu->kvm, vcpu->vcpu_id,
	69	timer->map,
	70	timer->irq->level);
05971120	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
d35268da CD	114	static bool kvm_timer_irq_can_fire(struct kvm_vcpu *vcpu)
	115	{
	116	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	117
	118	return !(timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) &&
	119	(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE) &&
	120	!kvm_vgic_get_phys_irq_active(timer->map);
	121	}
	122
1a748478 CD	123	bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
	124	{
	125	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	126	cycle_t cval, now;
	127
d35268da	128	if (!kvm_timer_irq_can_fire(vcpu))
1a748478 CD	129	return false;
	130
	131	cval = timer->cntv_cval;
	132	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
	133
	134	return cval <= now;
	135	}
	136
d35268da CD	137	/*
	138	* Schedule the background timer before calling kvm_vcpu_block, so that this
	139	* thread is removed from its waitqueue and made runnable when there's a timer
	140	* interrupt to handle.
	141	*/
	142	void kvm_timer_schedule(struct kvm_vcpu *vcpu)
	143	{
	144	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	145	u64 ns;
	146	cycle_t cval, now;
	147
	148	BUG_ON(timer_is_armed(timer));
	149
	150	/*
	151	* No need to schedule a background timer if the guest timer has
	152	* already expired, because kvm_vcpu_block will return before putting
	153	* the thread to sleep.
	154	*/
	155	if (kvm_timer_should_fire(vcpu))
	156	return;
	157
	158	/*
	159	* If the timer is not capable of raising interrupts (disabled or
	160	* masked), then there's no more work for us to do.
	161	*/
	162	if (!kvm_timer_irq_can_fire(vcpu))
	163	return;
	164
	165	/* The timer has not yet expired, schedule a background timer */
	166	cval = timer->cntv_cval;
	167	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
	168
	169	ns = cyclecounter_cyc2ns(timecounter->cc,
	170	cval - now,
	171	timecounter->mask,
	172	&timecounter->frac);
	173	timer_arm(timer, ns);
	174	}
	175
	176	void kvm_timer_unschedule(struct kvm_vcpu *vcpu)
	177	{
	178	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	179	timer_disarm(timer);
	180	}
	181
53e72406 MZ	182	/**
	183	* kvm_timer_flush_hwstate - prepare to move the virt timer to the cpu
	184	* @vcpu: The vcpu pointer
	185	*
d35268da CD	186	* Check if the virtual timer has expired while we were running in the host,
d35268da CD	187	* and inject an interrupt if that was the case.
53e72406 MZ	188	*/
	189	void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
	190	{
	191	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
cff9211e CD	192	bool phys_active;
cff9211e CD	193	int ret;
53e72406	194
1a748478 CD	195	if (kvm_timer_should_fire(vcpu))
1a748478 CD	196	kvm_timer_inject_irq(vcpu);
cff9211e CD	197
	198	/*
	199	* We keep track of whether the edge-triggered interrupt has been
	200	* signalled to the vgic/guest, and if so, we mask the interrupt and
	201	* the physical distributor to prevent the timer from raising a
	202	* physical interrupt whenever we run a guest, preventing forward
	203	* VCPU progress.
	204	*/
	205	if (kvm_vgic_get_phys_irq_active(timer->map))
	206	phys_active = true;
	207	else
	208	phys_active = false;
	209
	210	ret = irq_set_irqchip_state(timer->map->irq,
	211	IRQCHIP_STATE_ACTIVE,
	212	phys_active);
	213	WARN_ON(ret);
53e72406 MZ	214	}
	215
	216	/**
	217	* kvm_timer_sync_hwstate - sync timer state from cpu
	218	* @vcpu: The vcpu pointer
	219	*
d35268da CD	220	* Check if the virtual timer has expired while we were running in the guest,
d35268da CD	221	* and inject an interrupt if that was the case.
53e72406 MZ	222	*/
	223	void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
	224	{
	225	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
53e72406	226
53e72406 MZ	227	BUG_ON(timer_is_armed(timer));
53e72406 MZ	228
d35268da	229	if (kvm_timer_should_fire(vcpu))
53e72406	230	kvm_timer_inject_irq(vcpu);
53e72406 MZ	231	}
53e72406 MZ	232
f120cd65 MZ	233	int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
f120cd65 MZ	234	const struct kvm_irq_level *irq)
5ae7f87a AP	235	{
5ae7f87a AP	236	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
f120cd65	237	struct irq_phys_map *map;
5ae7f87a AP	238
	239	/*
	240	* The vcpu timer irq number cannot be determined in
	241	* kvm_timer_vcpu_init() because it is called much before
	242	* kvm_vcpu_set_target(). To handle this, we determine
	243	* vcpu timer irq number when the vcpu is reset.
	244	*/
	245	timer->irq = irq;
f120cd65	246
4ad9e16a CD	247	/*
	248	* The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8
	249	* and to 0 for ARMv7. We provide an implementation that always
	250	* resets the timer to be disabled and unmasked and is compliant with
	251	* the ARMv7 architecture.
	252	*/
	253	timer->cntv_ctl = 0;
	254
f120cd65 MZ	255	/*
	256	* Tell the VGIC that the virtual interrupt is tied to a
	257	* physical interrupt. We do that once per VCPU.
	258	*/
	259	map = kvm_vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
	260	if (WARN_ON(IS_ERR(map)))
	261	return PTR_ERR(map);
	262
	263	timer->map = map;
	264	return 0;
5ae7f87a AP	265	}
5ae7f87a AP	266
53e72406 MZ	267	void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
	268	{
	269	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	270
	271	INIT_WORK(&timer->expired, kvm_timer_inject_irq_work);
	272	hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
	273	timer->timer.function = kvm_timer_expire;
53e72406 MZ	274	}
	275
	276	static void kvm_timer_init_interrupt(void *info)
	277	{
5ae7f87a	278	enable_percpu_irq(host_vtimer_irq, 0);
53e72406 MZ	279	}
53e72406 MZ	280
39735a3a AP	281	int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
	282	{
	283	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	284
	285	switch (regid) {
	286	case KVM_REG_ARM_TIMER_CTL:
	287	timer->cntv_ctl = value;
	288	break;
	289	case KVM_REG_ARM_TIMER_CNT:
	290	vcpu->kvm->arch.timer.cntvoff = kvm_phys_timer_read() - value;
	291	break;
	292	case KVM_REG_ARM_TIMER_CVAL:
	293	timer->cntv_cval = value;
	294	break;
	295	default:
	296	return -1;
	297	}
	298	return 0;
	299	}
	300
	301	u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
	302	{
	303	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	304
	305	switch (regid) {
	306	case KVM_REG_ARM_TIMER_CTL:
	307	return timer->cntv_ctl;
	308	case KVM_REG_ARM_TIMER_CNT:
	309	return kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
	310	case KVM_REG_ARM_TIMER_CVAL:
	311	return timer->cntv_cval;
	312	}
	313	return (u64)-1;
	314	}
53e72406 MZ	315
	316	static int kvm_timer_cpu_notify(struct notifier_block *self,
	317	unsigned long action, void *cpu)
	318	{
	319	switch (action) {
	320	case CPU_STARTING:
	321	case CPU_STARTING_FROZEN:
	322	kvm_timer_init_interrupt(NULL);
	323	break;
	324	case CPU_DYING:
	325	case CPU_DYING_FROZEN:
5ae7f87a	326	disable_percpu_irq(host_vtimer_irq);
53e72406 MZ	327	break;
	328	}
	329
	330	return NOTIFY_OK;
	331	}
	332
	333	static struct notifier_block kvm_timer_cpu_nb = {
	334	.notifier_call = kvm_timer_cpu_notify,
	335	};
	336
	337	static const struct of_device_id arch_timer_of_match[] = {
	338	{ .compatible = "arm,armv7-timer", },
f61701e0	339	{ .compatible = "arm,armv8-timer", },
53e72406 MZ	340	{},
	341	};
	342
	343	int kvm_timer_hyp_init(void)
	344	{
	345	struct device_node *np;
	346	unsigned int ppi;
	347	int err;
	348
	349	timecounter = arch_timer_get_timecounter();
	350	if (!timecounter)
	351	return -ENODEV;
	352
	353	np = of_find_matching_node(NULL, arch_timer_of_match);
	354	if (!np) {
	355	kvm_err("kvm_arch_timer: can't find DT node\n");
	356	return -ENODEV;
	357	}
	358
	359	ppi = irq_of_parse_and_map(np, 2);
	360	if (!ppi) {
	361	kvm_err("kvm_arch_timer: no virtual timer interrupt\n");
	362	err = -EINVAL;
	363	goto out;
	364	}
	365
	366	err = request_percpu_irq(ppi, kvm_arch_timer_handler,
	367	"kvm guest timer", kvm_get_running_vcpus());
	368	if (err) {
	369	kvm_err("kvm_arch_timer: can't request interrupt %d (%d)\n",
	370	ppi, err);
	371	goto out;
	372	}
	373
5ae7f87a	374	host_vtimer_irq = ppi;
53e72406	375
553f809e	376	err = __register_cpu_notifier(&kvm_timer_cpu_nb);
53e72406 MZ	377	if (err) {
	378	kvm_err("Cannot register timer CPU notifier\n");
	379	goto out_free;
	380	}
	381
	382	wqueue = create_singlethread_workqueue("kvm_arch_timer");
	383	if (!wqueue) {
	384	err = -ENOMEM;
	385	goto out_free;
	386	}
	387
	388	kvm_info("%s IRQ%d\n", np->name, ppi);
	389	on_each_cpu(kvm_timer_init_interrupt, NULL, 1);
	390
	391	goto out;
	392	out_free:
	393	free_percpu_irq(ppi, kvm_get_running_vcpus());
	394	out:
	395	of_node_put(np);
	396	return err;
	397	}
	398
	399	void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
	400	{
	401	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
	402
	403	timer_disarm(timer);
f120cd65 MZ	404	if (timer->map)
f120cd65 MZ	405	kvm_vgic_unmap_phys_irq(vcpu, timer->map);
53e72406 MZ	406	}
53e72406 MZ	407
05971120	408	void kvm_timer_enable(struct kvm *kvm)
53e72406	409	{
05971120 CD	410	if (kvm->arch.timer.enabled)
	411	return;
	412
	413	/*
	414	* There is a potential race here between VCPUs starting for the first
	415	* time, which may be enabling the timer multiple times. That doesn't
	416	* hurt though, because we're just setting a variable to the same
	417	* variable that it already was. The important thing is that all
	418	* VCPUs have the enabled variable set, before entering the guest, if
	419	* the arch timers are enabled.
	420	*/
	421	if (timecounter && wqueue)
53e72406	422	kvm->arch.timer.enabled = 1;
05971120	423	}
53e72406	424
05971120 CD	425	void kvm_timer_init(struct kvm *kvm)
	426	{
	427	kvm->arch.timer.cntvoff = kvm_phys_timer_read();
53e72406	428	}