[mirror_ubuntu-bionic-kernel.git] / arch / x86 / kernel / kvm.c

/*
 * KVM paravirt_ops implementation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (C) 2007, Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 * Copyright IBM Corporation, 2007
 *   Authors: Anthony Liguori <aliguori@us.ibm.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/kvm_para.h>
#include <linux/cpu.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/hardirq.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/hash.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/kprobes.h>
#include <asm/timer.h>
#include <asm/cpu.h>
#include <asm/traps.h>
#include <asm/desc.h>
#include <asm/tlbflush.h>
#include <asm/idle.h>

static int kvmapf = 1;

static int parse_no_kvmapf(char *arg)
{
        kvmapf = 0;
        return 0;
}

early_param("no-kvmapf", parse_no_kvmapf);

static int steal_acc = 1;
static int parse_no_stealacc(char *arg)
{
        steal_acc = 0;
        return 0;
}

early_param("no-steal-acc", parse_no_stealacc);

static DEFINE_PER_CPU(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64);
static DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64);
static int has_steal_clock = 0;

/*
 * No need for any "IO delay" on KVM
 */
static void kvm_io_delay(void)
{
}

#define KVM_TASK_SLEEP_HASHBITS 8
#define KVM_TASK_SLEEP_HASHSIZE (1<<KVM_TASK_SLEEP_HASHBITS)

struct kvm_task_sleep_node {
	struct hlist_node link;
	wait_queue_head_t wq;
	u32 token;
	int cpu;
	bool halted;
};

static struct kvm_task_sleep_head {
	spinlock_t lock;
	struct hlist_head list;
} async_pf_sleepers[KVM_TASK_SLEEP_HASHSIZE];

static struct kvm_task_sleep_node *_find_apf_task(struct kvm_task_sleep_head *b,
						  u32 token)
{
	struct hlist_node *p;

	hlist_for_each(p, &b->list) {
		struct kvm_task_sleep_node *n =
			hlist_entry(p, typeof(*n), link);
		if (n->token == token)
			return n;
	}

	return NULL;
}

void kvm_async_pf_task_wait(u32 token)
{
	u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
	struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
	struct kvm_task_sleep_node n, *e;
	DEFINE_WAIT(wait);
	int cpu, idle;

	cpu = get_cpu();
	idle = idle_cpu(cpu);
	put_cpu();

	spin_lock(&b->lock);
	e = _find_apf_task(b, token);
	if (e) {
		/* dummy entry exist -> wake up was delivered ahead of PF */
		hlist_del(&e->link);
		kfree(e);
		spin_unlock(&b->lock);
		return;
	}

	n.token = token;
	n.cpu = smp_processor_id();
	n.halted = idle || preempt_count() > 1;
	init_waitqueue_head(&n.wq);
	hlist_add_head(&n.link, &b->list);
	spin_unlock(&b->lock);

	for (;;) {
		if (!n.halted)
			prepare_to_wait(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
		if (hlist_unhashed(&n.link))
			break;

		if (!n.halted) {
			local_irq_enable();
			schedule();
			local_irq_disable();
		} else {
			/*
			 * We cannot reschedule. So halt.
			 */
			native_safe_halt();
			local_irq_disable();
		}
	}
	if (!n.halted)
		finish_wait(&n.wq, &wait);

	return;
}
EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait);

static void apf_task_wake_one(struct kvm_task_sleep_node *n)
{
	hlist_del_init(&n->link);
	if (n->halted)
		smp_send_reschedule(n->cpu);
	else if (waitqueue_active(&n->wq))
		wake_up(&n->wq);
}

static void apf_task_wake_all(void)
{
	int i;

	for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++) {
		struct hlist_node *p, *next;
		struct kvm_task_sleep_head *b = &async_pf_sleepers[i];
		spin_lock(&b->lock);
		hlist_for_each_safe(p, next, &b->list) {
			struct kvm_task_sleep_node *n =
				hlist_entry(p, typeof(*n), link);
			if (n->cpu == smp_processor_id())
				apf_task_wake_one(n);
		}
		spin_unlock(&b->lock);
	}
}

void kvm_async_pf_task_wake(u32 token)
{
	u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
	struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
	struct kvm_task_sleep_node *n;

	if (token == ~0) {
		apf_task_wake_all();
		return;
	}

again:
	spin_lock(&b->lock);
	n = _find_apf_task(b, token);
	if (!n) {
		/*
		 * async PF was not yet handled.
		 * Add dummy entry for the token.
		 */
		n = kzalloc(sizeof(*n), GFP_ATOMIC);
		if (!n) {
			/*
			 * Allocation failed! Busy wait while other cpu
			 * handles async PF.
			 */
			spin_unlock(&b->lock);
			cpu_relax();
			goto again;
		}
		n->token = token;
		n->cpu = smp_processor_id();
		init_waitqueue_head(&n->wq);
		hlist_add_head(&n->link, &b->list);
	} else
		apf_task_wake_one(n);
	spin_unlock(&b->lock);
	return;
}
EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);

u32 kvm_read_and_reset_pf_reason(void)
{
	u32 reason = 0;

	if (__get_cpu_var(apf_reason).enabled) {
		reason = __get_cpu_var(apf_reason).reason;
		__get_cpu_var(apf_reason).reason = 0;
	}

	return reason;
}
EXPORT_SYMBOL_GPL(kvm_read_and_reset_pf_reason);

dotraplinkage void __kprobes
do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
{
	switch (kvm_read_and_reset_pf_reason()) {
	default:
		do_page_fault(regs, error_code);
		break;
	case KVM_PV_REASON_PAGE_NOT_PRESENT:
		/* page is swapped out by the host. */
		kvm_async_pf_task_wait((u32)read_cr2());
		break;
	case KVM_PV_REASON_PAGE_READY:
		rcu_irq_enter();
		exit_idle();
		kvm_async_pf_task_wake((u32)read_cr2());
		rcu_irq_exit();
		break;
	}
}

static void __init paravirt_ops_setup(void)
{
	pv_info.name = "KVM";
	pv_info.paravirt_enabled = 1;

	if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY))
		pv_cpu_ops.io_delay = kvm_io_delay;

#ifdef CONFIG_X86_IO_APIC
	no_timer_check = 1;
#endif
}

static void kvm_register_steal_time(void)
{
	int cpu = smp_processor_id();
	struct kvm_steal_time *st = &per_cpu(steal_time, cpu);

	if (!has_steal_clock)
		return;

	memset(st, 0, sizeof(*st));

	wrmsrl(MSR_KVM_STEAL_TIME, (__pa(st) | KVM_MSR_ENABLED));
	printk(KERN_INFO "kvm-stealtime: cpu %d, msr %lx\n",
		cpu, __pa(st));
}

void __cpuinit kvm_guest_cpu_init(void)
{
	if (!kvm_para_available())
		return;

	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
		u64 pa = __pa(&__get_cpu_var(apf_reason));

#ifdef CONFIG_PREEMPT
		pa |= KVM_ASYNC_PF_SEND_ALWAYS;
#endif
		wrmsrl(MSR_KVM_ASYNC_PF_EN, pa | KVM_ASYNC_PF_ENABLED);
		__get_cpu_var(apf_reason).enabled = 1;
		printk(KERN_INFO"KVM setup async PF for cpu %d\n",
		       smp_processor_id());
	}

	if (has_steal_clock)
		kvm_register_steal_time();
}

static void kvm_pv_disable_apf(void *unused)
{
	if (!__get_cpu_var(apf_reason).enabled)
		return;

	wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
	__get_cpu_var(apf_reason).enabled = 0;

	printk(KERN_INFO"Unregister pv shared memory for cpu %d\n",
	       smp_processor_id());
}

static int kvm_pv_reboot_notify(struct notifier_block *nb,
				unsigned long code, void *unused)
{
	if (code == SYS_RESTART)
		on_each_cpu(kvm_pv_disable_apf, NULL, 1);
	return NOTIFY_DONE;
}

static struct notifier_block kvm_pv_reboot_nb = {
	.notifier_call = kvm_pv_reboot_notify,
};

static u64 kvm_steal_clock(int cpu)
{
	u64 steal;
	struct kvm_steal_time *src;
	int version;

	src = &per_cpu(steal_time, cpu);
	do {
		version = src->version;
		rmb();
		steal = src->steal;
		rmb();
	} while ((version & 1) || (version != src->version));

	return steal;
}

void kvm_disable_steal_time(void)
{
	if (!has_steal_clock)
		return;

	wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
}

#ifdef CONFIG_SMP
static void __init kvm_smp_prepare_boot_cpu(void)
{
#ifdef CONFIG_KVM_CLOCK
	WARN_ON(kvm_register_clock("primary cpu clock"));
#endif
	kvm_guest_cpu_init();
	native_smp_prepare_boot_cpu();
}

static void __cpuinit kvm_guest_cpu_online(void *dummy)
{
	kvm_guest_cpu_init();
}

static void kvm_guest_cpu_offline(void *dummy)
{
	kvm_disable_steal_time();
	kvm_pv_disable_apf(NULL);
	apf_task_wake_all();
}

static int __cpuinit kvm_cpu_notify(struct notifier_block *self,
				    unsigned long action, void *hcpu)
{
	int cpu = (unsigned long)hcpu;
	switch (action) {
	case CPU_ONLINE:
	case CPU_DOWN_FAILED:
	case CPU_ONLINE_FROZEN:
		smp_call_function_single(cpu, kvm_guest_cpu_online, NULL, 0);
		break;
	case CPU_DOWN_PREPARE:
	case CPU_DOWN_PREPARE_FROZEN:
		smp_call_function_single(cpu, kvm_guest_cpu_offline, NULL, 1);
		break;
	default:
		break;
	}
	return NOTIFY_OK;
}

static struct notifier_block __cpuinitdata kvm_cpu_notifier = {
        .notifier_call  = kvm_cpu_notify,
};
#endif

static void __init kvm_apf_trap_init(void)
{
	set_intr_gate(14, &async_page_fault);
}

void __init kvm_guest_init(void)
{
	int i;

	if (!kvm_para_available())
		return;

	paravirt_ops_setup();
	register_reboot_notifier(&kvm_pv_reboot_nb);
	for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
		spin_lock_init(&async_pf_sleepers[i].lock);
	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF))
		x86_init.irqs.trap_init = kvm_apf_trap_init;

	if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
		has_steal_clock = 1;
		pv_time_ops.steal_clock = kvm_steal_clock;
	}

#ifdef CONFIG_SMP
	smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
	register_cpu_notifier(&kvm_cpu_notifier);
#else
	kvm_guest_cpu_init();
#endif
}

static __init int activate_jump_labels(void)
{
	if (has_steal_clock) {
		static_key_slow_inc(&paravirt_steal_enabled);
		if (steal_acc)
			static_key_slow_inc(&paravirt_steal_rq_enabled);
	}

	return 0;
}
arch_initcall(activate_jump_labels);
Commit	Line	Data
0cf1bfd2 MT	1	/*
	2	* KVM paravirt_ops implementation
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	17	*
	18	* Copyright (C) 2007, Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
	19	* Copyright IBM Corporation, 2007
	20	* Authors: Anthony Liguori <aliguori@us.ibm.com>
	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/kernel.h>
	25	#include <linux/kvm_para.h>
	26	#include <linux/cpu.h>
	27	#include <linux/mm.h>
1da8a77b	28	#include <linux/highmem.h>
096d14a3	29	#include <linux/hardirq.h>
fd10cde9 GN	30	#include <linux/notifier.h>
fd10cde9 GN	31	#include <linux/reboot.h>
631bc487 GN	32	#include <linux/hash.h>
	33	#include <linux/sched.h>
	34	#include <linux/slab.h>
	35	#include <linux/kprobes.h>
a90ede7b	36	#include <asm/timer.h>
fd10cde9	37	#include <asm/cpu.h>
631bc487 GN	38	#include <asm/traps.h>
631bc487 GN	39	#include <asm/desc.h>
6c047cd9	40	#include <asm/tlbflush.h>
e0875921	41	#include <asm/idle.h>
096d14a3	42
fd10cde9 GN	43	static int kvmapf = 1;
	44
	45	static int parse_no_kvmapf(char *arg)
	46	{
	47	kvmapf = 0;
	48	return 0;
	49	}
	50
	51	early_param("no-kvmapf", parse_no_kvmapf);
	52
d910f5c1 GC	53	static int steal_acc = 1;
	54	static int parse_no_stealacc(char *arg)
	55	{
	56	steal_acc = 0;
	57	return 0;
	58	}
	59
	60	early_param("no-steal-acc", parse_no_stealacc);
	61
fd10cde9	62	static DEFINE_PER_CPU(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64);
d910f5c1 GC	63	static DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64);
d910f5c1 GC	64	static int has_steal_clock = 0;
096d14a3	65
0cf1bfd2 MT	66	/*
	67	* No need for any "IO delay" on KVM
	68	*/
	69	static void kvm_io_delay(void)
	70	{
	71	}
	72
631bc487 GN	73	#define KVM_TASK_SLEEP_HASHBITS 8
	74	#define KVM_TASK_SLEEP_HASHSIZE (1<<KVM_TASK_SLEEP_HASHBITS)
	75
	76	struct kvm_task_sleep_node {
	77	struct hlist_node link;
	78	wait_queue_head_t wq;
	79	u32 token;
	80	int cpu;
6c047cd9	81	bool halted;
631bc487 GN	82	};
	83
	84	static struct kvm_task_sleep_head {
	85	spinlock_t lock;
	86	struct hlist_head list;
	87	} async_pf_sleepers[KVM_TASK_SLEEP_HASHSIZE];
	88
	89	static struct kvm_task_sleep_node _find_apf_task(struct kvm_task_sleep_head b,
	90	u32 token)
	91	{
	92	struct hlist_node *p;
	93
	94	hlist_for_each(p, &b->list) {
	95	struct kvm_task_sleep_node *n =
	96	hlist_entry(p, typeof(*n), link);
	97	if (n->token == token)
	98	return n;
	99	}
	100
	101	return NULL;
	102	}
	103
	104	void kvm_async_pf_task_wait(u32 token)
	105	{
	106	u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
	107	struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
	108	struct kvm_task_sleep_node n, *e;
	109	DEFINE_WAIT(wait);
6c047cd9 GN	110	int cpu, idle;
	111
	112	cpu = get_cpu();
	113	idle = idle_cpu(cpu);
	114	put_cpu();
631bc487 GN	115
	116	spin_lock(&b->lock);
	117	e = _find_apf_task(b, token);
	118	if (e) {
	119	/* dummy entry exist -> wake up was delivered ahead of PF */
	120	hlist_del(&e->link);
	121	kfree(e);
	122	spin_unlock(&b->lock);
	123	return;
	124	}
	125
	126	n.token = token;
	127	n.cpu = smp_processor_id();
6c047cd9	128	n.halted = idle \|\| preempt_count() > 1;
631bc487 GN	129	init_waitqueue_head(&n.wq);
	130	hlist_add_head(&n.link, &b->list);
	131	spin_unlock(&b->lock);
	132
	133	for (;;) {
6c047cd9 GN	134	if (!n.halted)
6c047cd9 GN	135	prepare_to_wait(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
631bc487 GN	136	if (hlist_unhashed(&n.link))
631bc487 GN	137	break;
6c047cd9 GN	138
	139	if (!n.halted) {
	140	local_irq_enable();
	141	schedule();
	142	local_irq_disable();
	143	} else {
	144	/*
	145	* We cannot reschedule. So halt.
	146	*/
	147	native_safe_halt();
	148	local_irq_disable();
	149	}
631bc487	150	}
6c047cd9 GN	151	if (!n.halted)
6c047cd9 GN	152	finish_wait(&n.wq, &wait);
631bc487 GN	153
	154	return;
	155	}
	156	EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait);
	157
	158	static void apf_task_wake_one(struct kvm_task_sleep_node *n)
	159	{
	160	hlist_del_init(&n->link);
6c047cd9 GN	161	if (n->halted)
	162	smp_send_reschedule(n->cpu);
	163	else if (waitqueue_active(&n->wq))
631bc487 GN	164	wake_up(&n->wq);
	165	}
	166
	167	static void apf_task_wake_all(void)
	168	{
	169	int i;
	170
	171	for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++) {
	172	struct hlist_node p, next;
	173	struct kvm_task_sleep_head *b = &async_pf_sleepers[i];
	174	spin_lock(&b->lock);
	175	hlist_for_each_safe(p, next, &b->list) {
	176	struct kvm_task_sleep_node *n =
	177	hlist_entry(p, typeof(*n), link);
	178	if (n->cpu == smp_processor_id())
	179	apf_task_wake_one(n);
	180	}
	181	spin_unlock(&b->lock);
	182	}
	183	}
	184
	185	void kvm_async_pf_task_wake(u32 token)
	186	{
	187	u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
	188	struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
	189	struct kvm_task_sleep_node *n;
	190
	191	if (token == ~0) {
	192	apf_task_wake_all();
	193	return;
	194	}
	195
	196	again:
	197	spin_lock(&b->lock);
	198	n = _find_apf_task(b, token);
	199	if (!n) {
	200	/*
	201	* async PF was not yet handled.
	202	* Add dummy entry for the token.
	203	*/
62c49cc9	204	n = kzalloc(sizeof(*n), GFP_ATOMIC);
631bc487 GN	205	if (!n) {
	206	/*
	207	* Allocation failed! Busy wait while other cpu
	208	* handles async PF.
	209	*/
	210	spin_unlock(&b->lock);
	211	cpu_relax();
	212	goto again;
	213	}
	214	n->token = token;
	215	n->cpu = smp_processor_id();
	216	init_waitqueue_head(&n->wq);
	217	hlist_add_head(&n->link, &b->list);
	218	} else
	219	apf_task_wake_one(n);
	220	spin_unlock(&b->lock);
	221	return;
	222	}
	223	EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);
	224
	225	u32 kvm_read_and_reset_pf_reason(void)
	226	{
	227	u32 reason = 0;
	228
	229	if (__get_cpu_var(apf_reason).enabled) {
	230	reason = __get_cpu_var(apf_reason).reason;
	231	__get_cpu_var(apf_reason).reason = 0;
	232	}
	233
	234	return reason;
	235	}
	236	EXPORT_SYMBOL_GPL(kvm_read_and_reset_pf_reason);
	237
	238	dotraplinkage void __kprobes
	239	do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
	240	{
	241	switch (kvm_read_and_reset_pf_reason()) {
	242	default:
	243	do_page_fault(regs, error_code);
	244	break;
	245	case KVM_PV_REASON_PAGE_NOT_PRESENT:
	246	/* page is swapped out by the host. */
	247	kvm_async_pf_task_wait((u32)read_cr2());
	248	break;
	249	case KVM_PV_REASON_PAGE_READY:
e0875921 GN	250	rcu_irq_enter();
e0875921 GN	251	exit_idle();
631bc487	252	kvm_async_pf_task_wake((u32)read_cr2());
e0875921	253	rcu_irq_exit();
631bc487 GN	254	break;
	255	}
	256	}
	257
d3ac8815	258	static void __init paravirt_ops_setup(void)
0cf1bfd2 MT	259	{
	260	pv_info.name = "KVM";
	261	pv_info.paravirt_enabled = 1;
	262
	263	if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY))
	264	pv_cpu_ops.io_delay = kvm_io_delay;
	265
a90ede7b MT	266	#ifdef CONFIG_X86_IO_APIC
	267	no_timer_check = 1;
	268	#endif
0cf1bfd2 MT	269	}
0cf1bfd2 MT	270
d910f5c1 GC	271	static void kvm_register_steal_time(void)
	272	{
	273	int cpu = smp_processor_id();
	274	struct kvm_steal_time *st = &per_cpu(steal_time, cpu);
	275
	276	if (!has_steal_clock)
	277	return;
	278
	279	memset(st, 0, sizeof(*st));
	280
	281	wrmsrl(MSR_KVM_STEAL_TIME, (__pa(st) \| KVM_MSR_ENABLED));
	282	printk(KERN_INFO "kvm-stealtime: cpu %d, msr %lx\n",
	283	cpu, __pa(st));
	284	}
	285
fd10cde9 GN	286	void __cpuinit kvm_guest_cpu_init(void)
	287	{
	288	if (!kvm_para_available())
	289	return;
	290
	291	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
	292	u64 pa = __pa(&__get_cpu_var(apf_reason));
	293
6adba527 GN	294	#ifdef CONFIG_PREEMPT
	295	pa \|= KVM_ASYNC_PF_SEND_ALWAYS;
	296	#endif
fd10cde9 GN	297	wrmsrl(MSR_KVM_ASYNC_PF_EN, pa \| KVM_ASYNC_PF_ENABLED);
	298	__get_cpu_var(apf_reason).enabled = 1;
	299	printk(KERN_INFO"KVM setup async PF for cpu %d\n",
	300	smp_processor_id());
	301	}
d910f5c1 GC	302
	303	if (has_steal_clock)
	304	kvm_register_steal_time();
fd10cde9 GN	305	}
	306
	307	static void kvm_pv_disable_apf(void *unused)
	308	{
	309	if (!__get_cpu_var(apf_reason).enabled)
	310	return;
	311
	312	wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
	313	__get_cpu_var(apf_reason).enabled = 0;
	314
	315	printk(KERN_INFO"Unregister pv shared memory for cpu %d\n",
	316	smp_processor_id());
	317	}
	318
	319	static int kvm_pv_reboot_notify(struct notifier_block *nb,
	320	unsigned long code, void *unused)
	321	{
	322	if (code == SYS_RESTART)
	323	on_each_cpu(kvm_pv_disable_apf, NULL, 1);
	324	return NOTIFY_DONE;
	325	}
	326
	327	static struct notifier_block kvm_pv_reboot_nb = {
	328	.notifier_call = kvm_pv_reboot_notify,
	329	};
	330
d910f5c1 GC	331	static u64 kvm_steal_clock(int cpu)
	332	{
	333	u64 steal;
	334	struct kvm_steal_time *src;
	335	int version;
	336
	337	src = &per_cpu(steal_time, cpu);
	338	do {
	339	version = src->version;
	340	rmb();
	341	steal = src->steal;
	342	rmb();
	343	} while ((version & 1) \|\| (version != src->version));
	344
	345	return steal;
	346	}
	347
	348	void kvm_disable_steal_time(void)
	349	{
	350	if (!has_steal_clock)
	351	return;
	352
	353	wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
	354	}
	355
ca3f1017 GN	356	#ifdef CONFIG_SMP
	357	static void __init kvm_smp_prepare_boot_cpu(void)
	358	{
a63512a4	359	#ifdef CONFIG_KVM_CLOCK
ca3f1017	360	WARN_ON(kvm_register_clock("primary cpu clock"));
a63512a4	361	#endif
fd10cde9	362	kvm_guest_cpu_init();
ca3f1017 GN	363	native_smp_prepare_boot_cpu();
ca3f1017 GN	364	}
fd10cde9	365
775077a0	366	static void __cpuinit kvm_guest_cpu_online(void *dummy)
fd10cde9 GN	367	{
	368	kvm_guest_cpu_init();
	369	}
	370
	371	static void kvm_guest_cpu_offline(void *dummy)
	372	{
d910f5c1	373	kvm_disable_steal_time();
fd10cde9	374	kvm_pv_disable_apf(NULL);
631bc487	375	apf_task_wake_all();
fd10cde9 GN	376	}
	377
	378	static int __cpuinit kvm_cpu_notify(struct notifier_block *self,
	379	unsigned long action, void *hcpu)
	380	{
	381	int cpu = (unsigned long)hcpu;
	382	switch (action) {
	383	case CPU_ONLINE:
	384	case CPU_DOWN_FAILED:
	385	case CPU_ONLINE_FROZEN:
	386	smp_call_function_single(cpu, kvm_guest_cpu_online, NULL, 0);
	387	break;
	388	case CPU_DOWN_PREPARE:
	389	case CPU_DOWN_PREPARE_FROZEN:
	390	smp_call_function_single(cpu, kvm_guest_cpu_offline, NULL, 1);
	391	break;
	392	default:
	393	break;
	394	}
	395	return NOTIFY_OK;
	396	}
	397
	398	static struct notifier_block __cpuinitdata kvm_cpu_notifier = {
	399	.notifier_call = kvm_cpu_notify,
	400	};
ca3f1017 GN	401	#endif
ca3f1017 GN	402
631bc487 GN	403	static void __init kvm_apf_trap_init(void)
	404	{
	405	set_intr_gate(14, &async_page_fault);
	406	}
	407
0cf1bfd2 MT	408	void __init kvm_guest_init(void)
0cf1bfd2 MT	409	{
631bc487 GN	410	int i;
631bc487 GN	411
0cf1bfd2 MT	412	if (!kvm_para_available())
	413	return;
	414
	415	paravirt_ops_setup();
fd10cde9	416	register_reboot_notifier(&kvm_pv_reboot_nb);
631bc487 GN	417	for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
	418	spin_lock_init(&async_pf_sleepers[i].lock);
	419	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF))
	420	x86_init.irqs.trap_init = kvm_apf_trap_init;
	421
d910f5c1 GC	422	if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
	423	has_steal_clock = 1;
	424	pv_time_ops.steal_clock = kvm_steal_clock;
	425	}
	426
ca3f1017 GN	427	#ifdef CONFIG_SMP
ca3f1017 GN	428	smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
fd10cde9 GN	429	register_cpu_notifier(&kvm_cpu_notifier);
	430	#else
	431	kvm_guest_cpu_init();
ca3f1017	432	#endif
0cf1bfd2	433	}
d910f5c1 GC	434
	435	static __init int activate_jump_labels(void)
	436	{
	437	if (has_steal_clock) {
c5905afb	438	static_key_slow_inc(&paravirt_steal_enabled);
d910f5c1	439	if (steal_acc)
c5905afb	440	static_key_slow_inc(&paravirt_steal_rq_enabled);
d910f5c1 GC	441	}
	442
	443	return 0;
	444	}
	445	arch_initcall(activate_jump_labels);