[deliverable/linux.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>

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;
	struct mm_struct *mm;
};

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.mm = current->active_mm;
	n.halted = idle || preempt_count() > 1;
	atomic_inc(&n.mm->mm_count);
	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->mm)
		return;
	mmdrop(n->mm);
	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 = kmalloc(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();
		n->mm = NULL;
		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:
		kvm_async_pf_task_wake((u32)read_cr2());
		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) {
		jump_label_inc(&paravirt_steal_enabled);
		if (steal_acc)
			jump_label_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>
096d14a3	41
fd10cde9 GN	42	static int kvmapf = 1;
	43
	44	static int parse_no_kvmapf(char *arg)
	45	{
	46	kvmapf = 0;
	47	return 0;
	48	}
	49
	50	early_param("no-kvmapf", parse_no_kvmapf);
	51
d910f5c1 GC	52	static int steal_acc = 1;
	53	static int parse_no_stealacc(char *arg)
	54	{
	55	steal_acc = 0;
	56	return 0;
	57	}
	58
	59	early_param("no-steal-acc", parse_no_stealacc);
	60
fd10cde9	61	static DEFINE_PER_CPU(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64);
d910f5c1 GC	62	static DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64);
d910f5c1 GC	63	static int has_steal_clock = 0;
096d14a3	64
0cf1bfd2 MT	65	/*
	66	* No need for any "IO delay" on KVM
	67	*/
	68	static void kvm_io_delay(void)
	69	{
	70	}
	71
631bc487 GN	72	#define KVM_TASK_SLEEP_HASHBITS 8
	73	#define KVM_TASK_SLEEP_HASHSIZE (1<<KVM_TASK_SLEEP_HASHBITS)
	74
	75	struct kvm_task_sleep_node {
	76	struct hlist_node link;
	77	wait_queue_head_t wq;
	78	u32 token;
	79	int cpu;
6c047cd9 GN	80	bool halted;
6c047cd9 GN	81	struct mm_struct *mm;
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 GN	128	n.mm = current->active_mm;
	129	n.halted = idle \|\| preempt_count() > 1;
	130	atomic_inc(&n.mm->mm_count);
631bc487 GN	131	init_waitqueue_head(&n.wq);
	132	hlist_add_head(&n.link, &b->list);
	133	spin_unlock(&b->lock);
	134
	135	for (;;) {
6c047cd9 GN	136	if (!n.halted)
6c047cd9 GN	137	prepare_to_wait(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
631bc487 GN	138	if (hlist_unhashed(&n.link))
631bc487 GN	139	break;
6c047cd9 GN	140
	141	if (!n.halted) {
	142	local_irq_enable();
	143	schedule();
	144	local_irq_disable();
	145	} else {
	146	/*
	147	* We cannot reschedule. So halt.
	148	*/
	149	native_safe_halt();
	150	local_irq_disable();
	151	}
631bc487	152	}
6c047cd9 GN	153	if (!n.halted)
6c047cd9 GN	154	finish_wait(&n.wq, &wait);
631bc487 GN	155
	156	return;
	157	}
	158	EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait);
	159
	160	static void apf_task_wake_one(struct kvm_task_sleep_node *n)
	161	{
	162	hlist_del_init(&n->link);
6c047cd9 GN	163	if (!n->mm)
	164	return;
	165	mmdrop(n->mm);
	166	if (n->halted)
	167	smp_send_reschedule(n->cpu);
	168	else if (waitqueue_active(&n->wq))
631bc487 GN	169	wake_up(&n->wq);
	170	}
	171
	172	static void apf_task_wake_all(void)
	173	{
	174	int i;
	175
	176	for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++) {
	177	struct hlist_node p, next;
	178	struct kvm_task_sleep_head *b = &async_pf_sleepers[i];
	179	spin_lock(&b->lock);
	180	hlist_for_each_safe(p, next, &b->list) {
	181	struct kvm_task_sleep_node *n =
	182	hlist_entry(p, typeof(*n), link);
	183	if (n->cpu == smp_processor_id())
	184	apf_task_wake_one(n);
	185	}
	186	spin_unlock(&b->lock);
	187	}
	188	}
	189
	190	void kvm_async_pf_task_wake(u32 token)
	191	{
	192	u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
	193	struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
	194	struct kvm_task_sleep_node *n;
	195
	196	if (token == ~0) {
	197	apf_task_wake_all();
	198	return;
	199	}
	200
	201	again:
	202	spin_lock(&b->lock);
	203	n = _find_apf_task(b, token);
	204	if (!n) {
	205	/*
	206	* async PF was not yet handled.
	207	* Add dummy entry for the token.
	208	*/
	209	n = kmalloc(sizeof(*n), GFP_ATOMIC);
	210	if (!n) {
	211	/*
	212	* Allocation failed! Busy wait while other cpu
	213	* handles async PF.
	214	*/
	215	spin_unlock(&b->lock);
	216	cpu_relax();
	217	goto again;
	218	}
	219	n->token = token;
	220	n->cpu = smp_processor_id();
6c047cd9	221	n->mm = NULL;
631bc487 GN	222	init_waitqueue_head(&n->wq);
	223	hlist_add_head(&n->link, &b->list);
	224	} else
	225	apf_task_wake_one(n);
	226	spin_unlock(&b->lock);
	227	return;
	228	}
	229	EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);
	230
	231	u32 kvm_read_and_reset_pf_reason(void)
	232	{
	233	u32 reason = 0;
	234
	235	if (__get_cpu_var(apf_reason).enabled) {
	236	reason = __get_cpu_var(apf_reason).reason;
	237	__get_cpu_var(apf_reason).reason = 0;
	238	}
	239
	240	return reason;
	241	}
	242	EXPORT_SYMBOL_GPL(kvm_read_and_reset_pf_reason);
	243
	244	dotraplinkage void __kprobes
	245	do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
	246	{
	247	switch (kvm_read_and_reset_pf_reason()) {
	248	default:
	249	do_page_fault(regs, error_code);
	250	break;
	251	case KVM_PV_REASON_PAGE_NOT_PRESENT:
	252	/* page is swapped out by the host. */
	253	kvm_async_pf_task_wait((u32)read_cr2());
	254	break;
	255	case KVM_PV_REASON_PAGE_READY:
	256	kvm_async_pf_task_wake((u32)read_cr2());
	257	break;
	258	}
	259	}
	260
d3ac8815	261	static void __init paravirt_ops_setup(void)
0cf1bfd2 MT	262	{
	263	pv_info.name = "KVM";
	264	pv_info.paravirt_enabled = 1;
	265
	266	if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY))
	267	pv_cpu_ops.io_delay = kvm_io_delay;
	268
a90ede7b MT	269	#ifdef CONFIG_X86_IO_APIC
	270	no_timer_check = 1;
	271	#endif
0cf1bfd2 MT	272	}
0cf1bfd2 MT	273
d910f5c1 GC	274	static void kvm_register_steal_time(void)
	275	{
	276	int cpu = smp_processor_id();
	277	struct kvm_steal_time *st = &per_cpu(steal_time, cpu);
	278
	279	if (!has_steal_clock)
	280	return;
	281
	282	memset(st, 0, sizeof(*st));
	283
	284	wrmsrl(MSR_KVM_STEAL_TIME, (__pa(st) \| KVM_MSR_ENABLED));
	285	printk(KERN_INFO "kvm-stealtime: cpu %d, msr %lx\n",
	286	cpu, __pa(st));
	287	}
	288
fd10cde9 GN	289	void __cpuinit kvm_guest_cpu_init(void)
	290	{
	291	if (!kvm_para_available())
	292	return;
	293
	294	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
	295	u64 pa = __pa(&__get_cpu_var(apf_reason));
	296
6adba527 GN	297	#ifdef CONFIG_PREEMPT
	298	pa \|= KVM_ASYNC_PF_SEND_ALWAYS;
	299	#endif
fd10cde9 GN	300	wrmsrl(MSR_KVM_ASYNC_PF_EN, pa \| KVM_ASYNC_PF_ENABLED);
	301	__get_cpu_var(apf_reason).enabled = 1;
	302	printk(KERN_INFO"KVM setup async PF for cpu %d\n",
	303	smp_processor_id());
	304	}
d910f5c1 GC	305
	306	if (has_steal_clock)
	307	kvm_register_steal_time();
fd10cde9 GN	308	}
	309
	310	static void kvm_pv_disable_apf(void *unused)
	311	{
	312	if (!__get_cpu_var(apf_reason).enabled)
	313	return;
	314
	315	wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
	316	__get_cpu_var(apf_reason).enabled = 0;
	317
	318	printk(KERN_INFO"Unregister pv shared memory for cpu %d\n",
	319	smp_processor_id());
	320	}
	321
	322	static int kvm_pv_reboot_notify(struct notifier_block *nb,
	323	unsigned long code, void *unused)
	324	{
	325	if (code == SYS_RESTART)
	326	on_each_cpu(kvm_pv_disable_apf, NULL, 1);
	327	return NOTIFY_DONE;
	328	}
	329
	330	static struct notifier_block kvm_pv_reboot_nb = {
	331	.notifier_call = kvm_pv_reboot_notify,
	332	};
	333
d910f5c1 GC	334	static u64 kvm_steal_clock(int cpu)
	335	{
	336	u64 steal;
	337	struct kvm_steal_time *src;
	338	int version;
	339
	340	src = &per_cpu(steal_time, cpu);
	341	do {
	342	version = src->version;
	343	rmb();
	344	steal = src->steal;
	345	rmb();
	346	} while ((version & 1) \|\| (version != src->version));
	347
	348	return steal;
	349	}
	350
	351	void kvm_disable_steal_time(void)
	352	{
	353	if (!has_steal_clock)
	354	return;
	355
	356	wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
	357	}
	358
ca3f1017 GN	359	#ifdef CONFIG_SMP
	360	static void __init kvm_smp_prepare_boot_cpu(void)
	361	{
a63512a4	362	#ifdef CONFIG_KVM_CLOCK
ca3f1017	363	WARN_ON(kvm_register_clock("primary cpu clock"));
a63512a4	364	#endif
fd10cde9	365	kvm_guest_cpu_init();
ca3f1017 GN	366	native_smp_prepare_boot_cpu();
ca3f1017 GN	367	}
fd10cde9	368
775077a0	369	static void __cpuinit kvm_guest_cpu_online(void *dummy)
fd10cde9 GN	370	{
	371	kvm_guest_cpu_init();
	372	}
	373
	374	static void kvm_guest_cpu_offline(void *dummy)
	375	{
d910f5c1	376	kvm_disable_steal_time();
fd10cde9	377	kvm_pv_disable_apf(NULL);
631bc487	378	apf_task_wake_all();
fd10cde9 GN	379	}
	380
	381	static int __cpuinit kvm_cpu_notify(struct notifier_block *self,
	382	unsigned long action, void *hcpu)
	383	{
	384	int cpu = (unsigned long)hcpu;
	385	switch (action) {
	386	case CPU_ONLINE:
	387	case CPU_DOWN_FAILED:
	388	case CPU_ONLINE_FROZEN:
	389	smp_call_function_single(cpu, kvm_guest_cpu_online, NULL, 0);
	390	break;
	391	case CPU_DOWN_PREPARE:
	392	case CPU_DOWN_PREPARE_FROZEN:
	393	smp_call_function_single(cpu, kvm_guest_cpu_offline, NULL, 1);
	394	break;
	395	default:
	396	break;
	397	}
	398	return NOTIFY_OK;
	399	}
	400
	401	static struct notifier_block __cpuinitdata kvm_cpu_notifier = {
	402	.notifier_call = kvm_cpu_notify,
	403	};
ca3f1017 GN	404	#endif
ca3f1017 GN	405
631bc487 GN	406	static void __init kvm_apf_trap_init(void)
	407	{
	408	set_intr_gate(14, &async_page_fault);
	409	}
	410
0cf1bfd2 MT	411	void __init kvm_guest_init(void)
0cf1bfd2 MT	412	{
631bc487 GN	413	int i;
631bc487 GN	414
0cf1bfd2 MT	415	if (!kvm_para_available())
	416	return;
	417
	418	paravirt_ops_setup();
fd10cde9	419	register_reboot_notifier(&kvm_pv_reboot_nb);
631bc487 GN	420	for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
	421	spin_lock_init(&async_pf_sleepers[i].lock);
	422	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF))
	423	x86_init.irqs.trap_init = kvm_apf_trap_init;
	424
d910f5c1 GC	425	if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
	426	has_steal_clock = 1;
	427	pv_time_ops.steal_clock = kvm_steal_clock;
	428	}
	429
ca3f1017 GN	430	#ifdef CONFIG_SMP
ca3f1017 GN	431	smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
fd10cde9 GN	432	register_cpu_notifier(&kvm_cpu_notifier);
	433	#else
	434	kvm_guest_cpu_init();
ca3f1017	435	#endif
0cf1bfd2	436	}
d910f5c1 GC	437
	438	static __init int activate_jump_labels(void)
	439	{
	440	if (has_steal_clock) {
	441	jump_label_inc(&paravirt_steal_enabled);
	442	if (steal_acc)
	443	jump_label_inc(&paravirt_steal_rq_enabled);
	444	}
	445
	446	return 0;
	447	}
	448	arch_initcall(activate_jump_labels);