1 files changed, 2114 insertions, 0 deletions

diff --git a/kernel/arch/x86/kvm/lapic.c b/kernel/arch/x86/kvm/lapic.c
new file mode 100644
index 000000000..525db8be0
--- /dev/null
+++ b/kernel/arch/x86/kvm/lapic.c
@@ -0,0 +1,2114 @@
+
+/*
+ * Local APIC virtualization
+ *
+ * Copyright (C) 2006 Qumranet, Inc.
+ * Copyright (C) 2007 Novell
+ * Copyright (C) 2007 Intel
+ * Copyright 2009 Red Hat, Inc. and/or its affiliates.
+ *
+ * Authors:
+ *   Dor Laor <dor.laor@qumranet.com>
+ *   Gregory Haskins <ghaskins@novell.com>
+ *   Yaozu (Eddie) Dong <eddie.dong@intel.com>
+ *
+ * Based on Xen 3.1 code, Copyright (c) 2004, Intel Corporation.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/smp.h>
+#include <linux/hrtimer.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/math64.h>
+#include <linux/slab.h>
+#include <asm/processor.h>
+#include <asm/msr.h>
+#include <asm/page.h>
+#include <asm/current.h>
+#include <asm/apicdef.h>
+#include <asm/delay.h>
+#include <linux/atomic.h>
+#include <linux/jump_label.h>
+#include "kvm_cache_regs.h"
+#include "irq.h"
+#include "trace.h"
+#include "x86.h"
+#include "cpuid.h"
+
+#ifndef CONFIG_X86_64
+#define mod_64(x, y) ((x) - (y) * div64_u64(x, y))
+#else
+#define mod_64(x, y) ((x) % (y))
+#endif
+
+#define PRId64 "d"
+#define PRIx64 "llx"
+#define PRIu64 "u"
+#define PRIo64 "o"
+
+#define APIC_BUS_CYCLE_NS 1
+
+/* #define apic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg) */
+#define apic_debug(fmt, arg...)
+
+#define APIC_LVT_NUM			6
+/* 14 is the version for Xeon and Pentium 8.4.8*/
+#define APIC_VERSION			(0x14UL | ((APIC_LVT_NUM - 1) << 16))
+#define LAPIC_MMIO_LENGTH		(1 << 12)
+/* followed define is not in apicdef.h */
+#define APIC_SHORT_MASK			0xc0000
+#define APIC_DEST_NOSHORT		0x0
+#define APIC_DEST_MASK			0x800
+#define MAX_APIC_VECTOR			256
+#define APIC_VECTORS_PER_REG		32
+
+#define APIC_BROADCAST			0xFF
+#define X2APIC_BROADCAST		0xFFFFFFFFul
+
+#define VEC_POS(v) ((v) & (32 - 1))
+#define REG_POS(v) (((v) >> 5) << 4)
+
+static inline void apic_set_reg(struct kvm_lapic *apic, int reg_off, u32 val)
+{
+	*((u32 *) (apic->regs + reg_off)) = val;
+}
+
+static inline int apic_test_vector(int vec, void *bitmap)
+{
+	return test_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
+}
+
+bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	return apic_test_vector(vector, apic->regs + APIC_ISR) ||
+		apic_test_vector(vector, apic->regs + APIC_IRR);
+}
+
+static inline void apic_set_vector(int vec, void *bitmap)
+{
+	set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
+}
+
+static inline void apic_clear_vector(int vec, void *bitmap)
+{
+	clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
+}
+
+static inline int __apic_test_and_set_vector(int vec, void *bitmap)
+{
+	return __test_and_set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
+}
+
+static inline int __apic_test_and_clear_vector(int vec, void *bitmap)
+{
+	return __test_and_clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
+}
+
+struct static_key_deferred apic_hw_disabled __read_mostly;
+struct static_key_deferred apic_sw_disabled __read_mostly;
+
+static inline int apic_enabled(struct kvm_lapic *apic)
+{
+	return kvm_apic_sw_enabled(apic) &&	kvm_apic_hw_enabled(apic);
+}
+
+#define LVT_MASK	\
+	(APIC_LVT_MASKED | APIC_SEND_PENDING | APIC_VECTOR_MASK)
+
+#define LINT_MASK	\
+	(LVT_MASK | APIC_MODE_MASK | APIC_INPUT_POLARITY | \
+	 APIC_LVT_REMOTE_IRR | APIC_LVT_LEVEL_TRIGGER)
+
+static inline int kvm_apic_id(struct kvm_lapic *apic)
+{
+	return (kvm_apic_get_reg(apic, APIC_ID) >> 24) & 0xff;
+}
+
+/* The logical map is definitely wrong if we have multiple
+ * modes at the same time.  (Physical map is always right.)
+ */
+static inline bool kvm_apic_logical_map_valid(struct kvm_apic_map *map)
+{
+	return !(map->mode & (map->mode - 1));
+}
+
+static inline void
+apic_logical_id(struct kvm_apic_map *map, u32 dest_id, u16 *cid, u16 *lid)
+{
+	unsigned lid_bits;
+
+	BUILD_BUG_ON(KVM_APIC_MODE_XAPIC_CLUSTER !=  4);
+	BUILD_BUG_ON(KVM_APIC_MODE_XAPIC_FLAT    !=  8);
+	BUILD_BUG_ON(KVM_APIC_MODE_X2APIC        != 16);
+	lid_bits = map->mode;
+
+	*cid = dest_id >> lid_bits;
+	*lid = dest_id & ((1 << lid_bits) - 1);
+}
+
+static void recalculate_apic_map(struct kvm *kvm)
+{
+	struct kvm_apic_map *new, *old = NULL;
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	new = kzalloc(sizeof(struct kvm_apic_map), GFP_KERNEL);
+
+	mutex_lock(&kvm->arch.apic_map_lock);
+
+	if (!new)
+		goto out;
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		struct kvm_lapic *apic = vcpu->arch.apic;
+		u16 cid, lid;
+		u32 ldr, aid;
+
+		if (!kvm_apic_present(vcpu))
+			continue;
+
+		aid = kvm_apic_id(apic);
+		ldr = kvm_apic_get_reg(apic, APIC_LDR);
+
+		if (aid < ARRAY_SIZE(new->phys_map))
+			new->phys_map[aid] = apic;
+
+		if (apic_x2apic_mode(apic)) {
+			new->mode |= KVM_APIC_MODE_X2APIC;
+		} else if (ldr) {
+			ldr = GET_APIC_LOGICAL_ID(ldr);
+			if (kvm_apic_get_reg(apic, APIC_DFR) == APIC_DFR_FLAT)
+				new->mode |= KVM_APIC_MODE_XAPIC_FLAT;
+			else
+				new->mode |= KVM_APIC_MODE_XAPIC_CLUSTER;
+		}
+
+		if (!kvm_apic_logical_map_valid(new))
+			continue;
+
+		apic_logical_id(new, ldr, &cid, &lid);
+
+		if (lid && cid < ARRAY_SIZE(new->logical_map))
+			new->logical_map[cid][ffs(lid) - 1] = apic;
+	}
+out:
+	old = rcu_dereference_protected(kvm->arch.apic_map,
+			lockdep_is_held(&kvm->arch.apic_map_lock));
+	rcu_assign_pointer(kvm->arch.apic_map, new);
+	mutex_unlock(&kvm->arch.apic_map_lock);
+
+	if (old)
+		kfree_rcu(old, rcu);
+
+	kvm_vcpu_request_scan_ioapic(kvm);
+}
+
+static inline void apic_set_spiv(struct kvm_lapic *apic, u32 val)
+{
+	bool enabled = val & APIC_SPIV_APIC_ENABLED;
+
+	apic_set_reg(apic, APIC_SPIV, val);
+
+	if (enabled != apic->sw_enabled) {
+		apic->sw_enabled = enabled;
+		if (enabled) {
+			static_key_slow_dec_deferred(&apic_sw_disabled);
+			recalculate_apic_map(apic->vcpu->kvm);
+		} else
+			static_key_slow_inc(&apic_sw_disabled.key);
+	}
+}
+
+static inline void kvm_apic_set_id(struct kvm_lapic *apic, u8 id)
+{
+	apic_set_reg(apic, APIC_ID, id << 24);
+	recalculate_apic_map(apic->vcpu->kvm);
+}
+
+static inline void kvm_apic_set_ldr(struct kvm_lapic *apic, u32 id)
+{
+	apic_set_reg(apic, APIC_LDR, id);
+	recalculate_apic_map(apic->vcpu->kvm);
+}
+
+static inline int apic_lvt_enabled(struct kvm_lapic *apic, int lvt_type)
+{
+	return !(kvm_apic_get_reg(apic, lvt_type) & APIC_LVT_MASKED);
+}
+
+static inline int apic_lvt_vector(struct kvm_lapic *apic, int lvt_type)
+{
+	return kvm_apic_get_reg(apic, lvt_type) & APIC_VECTOR_MASK;
+}
+
+static inline int apic_lvtt_oneshot(struct kvm_lapic *apic)
+{
+	return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_ONESHOT;
+}
+
+static inline int apic_lvtt_period(struct kvm_lapic *apic)
+{
+	return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_PERIODIC;
+}
+
+static inline int apic_lvtt_tscdeadline(struct kvm_lapic *apic)
+{
+	return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_TSCDEADLINE;
+}
+
+static inline int apic_lvt_nmi_mode(u32 lvt_val)
+{
+	return (lvt_val & (APIC_MODE_MASK | APIC_LVT_MASKED)) == APIC_DM_NMI;
+}
+
+void kvm_apic_set_version(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	struct kvm_cpuid_entry2 *feat;
+	u32 v = APIC_VERSION;
+
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return;
+
+	feat = kvm_find_cpuid_entry(apic->vcpu, 0x1, 0);
+	if (feat && (feat->ecx & (1 << (X86_FEATURE_X2APIC & 31))))
+		v |= APIC_LVR_DIRECTED_EOI;
+	apic_set_reg(apic, APIC_LVR, v);
+}
+
+static const unsigned int apic_lvt_mask[APIC_LVT_NUM] = {
+	LVT_MASK ,      /* part LVTT mask, timer mode mask added at runtime */
+	LVT_MASK | APIC_MODE_MASK,	/* LVTTHMR */
+	LVT_MASK | APIC_MODE_MASK,	/* LVTPC */
+	LINT_MASK, LINT_MASK,	/* LVT0-1 */
+	LVT_MASK		/* LVTERR */
+};
+
+static int find_highest_vector(void *bitmap)
+{
+	int vec;
+	u32 *reg;
+
+	for (vec = MAX_APIC_VECTOR - APIC_VECTORS_PER_REG;
+	     vec >= 0; vec -= APIC_VECTORS_PER_REG) {
+		reg = bitmap + REG_POS(vec);
+		if (*reg)
+			return fls(*reg) - 1 + vec;
+	}
+
+	return -1;
+}
+
+static u8 count_vectors(void *bitmap)
+{
+	int vec;
+	u32 *reg;
+	u8 count = 0;
+
+	for (vec = 0; vec < MAX_APIC_VECTOR; vec += APIC_VECTORS_PER_REG) {
+		reg = bitmap + REG_POS(vec);
+		count += hweight32(*reg);
+	}
+
+	return count;
+}
+
+void __kvm_apic_update_irr(u32 *pir, void *regs)
+{
+	u32 i, pir_val;
+
+	for (i = 0; i <= 7; i++) {
+		pir_val = xchg(&pir[i], 0);
+		if (pir_val)
+			*((u32 *)(regs + APIC_IRR + i * 0x10)) |= pir_val;
+	}
+}
+EXPORT_SYMBOL_GPL(__kvm_apic_update_irr);
+
+void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	__kvm_apic_update_irr(pir, apic->regs);
+}
+EXPORT_SYMBOL_GPL(kvm_apic_update_irr);
+
+static inline void apic_set_irr(int vec, struct kvm_lapic *apic)
+{
+	apic_set_vector(vec, apic->regs + APIC_IRR);
+	/*
+	 * irr_pending must be true if any interrupt is pending; set it after
+	 * APIC_IRR to avoid race with apic_clear_irr
+	 */
+	apic->irr_pending = true;
+}
+
+static inline int apic_search_irr(struct kvm_lapic *apic)
+{
+	return find_highest_vector(apic->regs + APIC_IRR);
+}
+
+static inline int apic_find_highest_irr(struct kvm_lapic *apic)
+{
+	int result;
+
+	/*
+	 * Note that irr_pending is just a hint. It will be always
+	 * true with virtual interrupt delivery enabled.
+	 */
+	if (!apic->irr_pending)
+		return -1;
+
+	kvm_x86_ops->sync_pir_to_irr(apic->vcpu);
+	result = apic_search_irr(apic);
+	ASSERT(result == -1 || result >= 16);
+
+	return result;
+}
+
+static inline void apic_clear_irr(int vec, struct kvm_lapic *apic)
+{
+	struct kvm_vcpu *vcpu;
+
+	vcpu = apic->vcpu;
+
+	if (unlikely(kvm_apic_vid_enabled(vcpu->kvm))) {
+		/* try to update RVI */
+		apic_clear_vector(vec, apic->regs + APIC_IRR);
+		kvm_make_request(KVM_REQ_EVENT, vcpu);
+	} else {
+		apic->irr_pending = false;
+		apic_clear_vector(vec, apic->regs + APIC_IRR);
+		if (apic_search_irr(apic) != -1)
+			apic->irr_pending = true;
+	}
+}
+
+static inline void apic_set_isr(int vec, struct kvm_lapic *apic)
+{
+	struct kvm_vcpu *vcpu;
+
+	if (__apic_test_and_set_vector(vec, apic->regs + APIC_ISR))
+		return;
+
+	vcpu = apic->vcpu;
+
+	/*
+	 * With APIC virtualization enabled, all caching is disabled
+	 * because the processor can modify ISR under the hood.  Instead
+	 * just set SVI.
+	 */
+	if (unlikely(kvm_x86_ops->hwapic_isr_update))
+		kvm_x86_ops->hwapic_isr_update(vcpu->kvm, vec);
+	else {
+		++apic->isr_count;
+		BUG_ON(apic->isr_count > MAX_APIC_VECTOR);
+		/*
+		 * ISR (in service register) bit is set when injecting an interrupt.
+		 * The highest vector is injected. Thus the latest bit set matches
+		 * the highest bit in ISR.
+		 */
+		apic->highest_isr_cache = vec;
+	}
+}
+
+static inline int apic_find_highest_isr(struct kvm_lapic *apic)
+{
+	int result;
+
+	/*
+	 * Note that isr_count is always 1, and highest_isr_cache
+	 * is always -1, with APIC virtualization enabled.
+	 */
+	if (!apic->isr_count)
+		return -1;
+	if (likely(apic->highest_isr_cache != -1))
+		return apic->highest_isr_cache;
+
+	result = find_highest_vector(apic->regs + APIC_ISR);
+	ASSERT(result == -1 || result >= 16);
+
+	return result;
+}
+
+static inline void apic_clear_isr(int vec, struct kvm_lapic *apic)
+{
+	struct kvm_vcpu *vcpu;
+	if (!__apic_test_and_clear_vector(vec, apic->regs + APIC_ISR))
+		return;
+
+	vcpu = apic->vcpu;
+
+	/*
+	 * We do get here for APIC virtualization enabled if the guest
+	 * uses the Hyper-V APIC enlightenment.  In this case we may need
+	 * to trigger a new interrupt delivery by writing the SVI field;
+	 * on the other hand isr_count and highest_isr_cache are unused
+	 * and must be left alone.
+	 */
+	if (unlikely(kvm_x86_ops->hwapic_isr_update))
+		kvm_x86_ops->hwapic_isr_update(vcpu->kvm,
+					       apic_find_highest_isr(apic));
+	else {
+		--apic->isr_count;
+		BUG_ON(apic->isr_count < 0);
+		apic->highest_isr_cache = -1;
+	}
+}
+
+int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu)
+{
+	int highest_irr;
+
+	/* This may race with setting of irr in __apic_accept_irq() and
+	 * value returned may be wrong, but kvm_vcpu_kick() in __apic_accept_irq
+	 * will cause vmexit immediately and the value will be recalculated
+	 * on the next vmentry.
+	 */
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return 0;
+	highest_irr = apic_find_highest_irr(vcpu->arch.apic);
+
+	return highest_irr;
+}
+
+static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
+			     int vector, int level, int trig_mode,
+			     unsigned long *dest_map);
+
+int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
+		unsigned long *dest_map)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	return __apic_accept_irq(apic, irq->delivery_mode, irq->vector,
+			irq->level, irq->trig_mode, dest_map);
+}
+
+static int pv_eoi_put_user(struct kvm_vcpu *vcpu, u8 val)
+{
+
+	return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data, &val,
+				      sizeof(val));
+}
+
+static int pv_eoi_get_user(struct kvm_vcpu *vcpu, u8 *val)
+{
+
+	return kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data, val,
+				      sizeof(*val));
+}
+
+static inline bool pv_eoi_enabled(struct kvm_vcpu *vcpu)
+{
+	return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
+}
+
+static bool pv_eoi_get_pending(struct kvm_vcpu *vcpu)
+{
+	u8 val;
+	if (pv_eoi_get_user(vcpu, &val) < 0)
+		apic_debug("Can't read EOI MSR value: 0x%llx\n",
+			   (unsigned long long)vcpu->arch.pv_eoi.msr_val);
+	return val & 0x1;
+}
+
+static void pv_eoi_set_pending(struct kvm_vcpu *vcpu)
+{
+	if (pv_eoi_put_user(vcpu, KVM_PV_EOI_ENABLED) < 0) {
+		apic_debug("Can't set EOI MSR value: 0x%llx\n",
+			   (unsigned long long)vcpu->arch.pv_eoi.msr_val);
+		return;
+	}
+	__set_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
+}
+
+static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu)
+{
+	if (pv_eoi_put_user(vcpu, KVM_PV_EOI_DISABLED) < 0) {
+		apic_debug("Can't clear EOI MSR value: 0x%llx\n",
+			   (unsigned long long)vcpu->arch.pv_eoi.msr_val);
+		return;
+	}
+	__clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
+}
+
+void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	int i;
+
+	for (i = 0; i < 8; i++)
+		apic_set_reg(apic, APIC_TMR + 0x10 * i, tmr[i]);
+}
+
+static void apic_update_ppr(struct kvm_lapic *apic)
+{
+	u32 tpr, isrv, ppr, old_ppr;
+	int isr;
+
+	old_ppr = kvm_apic_get_reg(apic, APIC_PROCPRI);
+	tpr = kvm_apic_get_reg(apic, APIC_TASKPRI);
+	isr = apic_find_highest_isr(apic);
+	isrv = (isr != -1) ? isr : 0;
+
+	if ((tpr & 0xf0) >= (isrv & 0xf0))
+		ppr = tpr & 0xff;
+	else
+		ppr = isrv & 0xf0;
+
+	apic_debug("vlapic %p, ppr 0x%x, isr 0x%x, isrv 0x%x",
+		   apic, ppr, isr, isrv);
+
+	if (old_ppr != ppr) {
+		apic_set_reg(apic, APIC_PROCPRI, ppr);
+		if (ppr < old_ppr)
+			kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
+	}
+}
+
+static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr)
+{
+	apic_set_reg(apic, APIC_TASKPRI, tpr);
+	apic_update_ppr(apic);
+}
+
+static bool kvm_apic_broadcast(struct kvm_lapic *apic, u32 mda)
+{
+	if (apic_x2apic_mode(apic))
+		return mda == X2APIC_BROADCAST;
+
+	return GET_APIC_DEST_FIELD(mda) == APIC_BROADCAST;
+}
+
+static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda)
+{
+	if (kvm_apic_broadcast(apic, mda))
+		return true;
+
+	if (apic_x2apic_mode(apic))
+		return mda == kvm_apic_id(apic);
+
+	return mda == SET_APIC_DEST_FIELD(kvm_apic_id(apic));
+}
+
+static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda)
+{
+	u32 logical_id;
+
+	if (kvm_apic_broadcast(apic, mda))
+		return true;
+
+	logical_id = kvm_apic_get_reg(apic, APIC_LDR);
+
+	if (apic_x2apic_mode(apic))
+		return ((logical_id >> 16) == (mda >> 16))
+		       && (logical_id & mda & 0xffff) != 0;
+
+	logical_id = GET_APIC_LOGICAL_ID(logical_id);
+	mda = GET_APIC_DEST_FIELD(mda);
+
+	switch (kvm_apic_get_reg(apic, APIC_DFR)) {
+	case APIC_DFR_FLAT:
+		return (logical_id & mda) != 0;
+	case APIC_DFR_CLUSTER:
+		return ((logical_id >> 4) == (mda >> 4))
+		       && (logical_id & mda & 0xf) != 0;
+	default:
+		apic_debug("Bad DFR vcpu %d: %08x\n",
+			   apic->vcpu->vcpu_id, kvm_apic_get_reg(apic, APIC_DFR));
+		return false;
+	}
+}
+
+/* KVM APIC implementation has two quirks
+ *  - dest always begins at 0 while xAPIC MDA has offset 24,
+ *  - IOxAPIC messages have to be delivered (directly) to x2APIC.
+ */
+static u32 kvm_apic_mda(unsigned int dest_id, struct kvm_lapic *source,
+                                              struct kvm_lapic *target)
+{
+	bool ipi = source != NULL;
+	bool x2apic_mda = apic_x2apic_mode(ipi ? source : target);
+
+	if (!ipi && dest_id == APIC_BROADCAST && x2apic_mda)
+		return X2APIC_BROADCAST;
+
+	return x2apic_mda ? dest_id : SET_APIC_DEST_FIELD(dest_id);
+}
+
+bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
+			   int short_hand, unsigned int dest, int dest_mode)
+{
+	struct kvm_lapic *target = vcpu->arch.apic;
+	u32 mda = kvm_apic_mda(dest, source, target);
+
+	apic_debug("target %p, source %p, dest 0x%x, "
+		   "dest_mode 0x%x, short_hand 0x%x\n",
+		   target, source, dest, dest_mode, short_hand);
+
+	ASSERT(target);
+	switch (short_hand) {
+	case APIC_DEST_NOSHORT:
+		if (dest_mode == APIC_DEST_PHYSICAL)
+			return kvm_apic_match_physical_addr(target, mda);
+		else
+			return kvm_apic_match_logical_addr(target, mda);
+	case APIC_DEST_SELF:
+		return target == source;
+	case APIC_DEST_ALLINC:
+		return true;
+	case APIC_DEST_ALLBUT:
+		return target != source;
+	default:
+		apic_debug("kvm: apic: Bad dest shorthand value %x\n",
+			   short_hand);
+		return false;
+	}
+}
+
+bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
+		struct kvm_lapic_irq *irq, int *r, unsigned long *dest_map)
+{
+	struct kvm_apic_map *map;
+	unsigned long bitmap = 1;
+	struct kvm_lapic **dst;
+	int i;
+	bool ret, x2apic_ipi;
+
+	*r = -1;
+
+	if (irq->shorthand == APIC_DEST_SELF) {
+		*r = kvm_apic_set_irq(src->vcpu, irq, dest_map);
+		return true;
+	}
+
+	if (irq->shorthand)
+		return false;
+
+	x2apic_ipi = src && apic_x2apic_mode(src);
+	if (irq->dest_id == (x2apic_ipi ? X2APIC_BROADCAST : APIC_BROADCAST))
+		return false;
+
+	ret = true;
+	rcu_read_lock();
+	map = rcu_dereference(kvm->arch.apic_map);
+
+	if (!map) {
+		ret = false;
+		goto out;
+	}
+
+	if (irq->dest_mode == APIC_DEST_PHYSICAL) {
+		if (irq->dest_id >= ARRAY_SIZE(map->phys_map))
+			goto out;
+
+		dst = &map->phys_map[irq->dest_id];
+	} else {
+		u16 cid;
+
+		if (!kvm_apic_logical_map_valid(map)) {
+			ret = false;
+			goto out;
+		}
+
+		apic_logical_id(map, irq->dest_id, &cid, (u16 *)&bitmap);
+
+		if (cid >= ARRAY_SIZE(map->logical_map))
+			goto out;
+
+		dst = map->logical_map[cid];
+
+		if (irq->delivery_mode == APIC_DM_LOWEST) {
+			int l = -1;
+			for_each_set_bit(i, &bitmap, 16) {
+				if (!dst[i])
+					continue;
+				if (l < 0)
+					l = i;
+				else if (kvm_apic_compare_prio(dst[i]->vcpu, dst[l]->vcpu) < 0)
+					l = i;
+			}
+
+			bitmap = (l >= 0) ? 1 << l : 0;
+		}
+	}
+
+	for_each_set_bit(i, &bitmap, 16) {
+		if (!dst[i])
+			continue;
+		if (*r < 0)
+			*r = 0;
+		*r += kvm_apic_set_irq(dst[i]->vcpu, irq, dest_map);
+	}
+out:
+	rcu_read_unlock();
+	return ret;
+}
+
+/*
+ * Add a pending IRQ into lapic.
+ * Return 1 if successfully added and 0 if discarded.
+ */
+static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
+			     int vector, int level, int trig_mode,
+			     unsigned long *dest_map)
+{
+	int result = 0;
+	struct kvm_vcpu *vcpu = apic->vcpu;
+
+	trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
+				  trig_mode, vector);
+	switch (delivery_mode) {
+	case APIC_DM_LOWEST:
+		vcpu->arch.apic_arb_prio++;
+	case APIC_DM_FIXED:
+		/* FIXME add logic for vcpu on reset */
+		if (unlikely(!apic_enabled(apic)))
+			break;
+
+		result = 1;
+
+		if (dest_map)
+			__set_bit(vcpu->vcpu_id, dest_map);
+
+		if (kvm_x86_ops->deliver_posted_interrupt)
+			kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
+		else {
+			apic_set_irr(vector, apic);
+
+			kvm_make_request(KVM_REQ_EVENT, vcpu);
+			kvm_vcpu_kick(vcpu);
+		}
+		break;
+
+	case APIC_DM_REMRD:
+		result = 1;
+		vcpu->arch.pv.pv_unhalted = 1;
+		kvm_make_request(KVM_REQ_EVENT, vcpu);
+		kvm_vcpu_kick(vcpu);
+		break;
+
+	case APIC_DM_SMI:
+		apic_debug("Ignoring guest SMI\n");
+		break;
+
+	case APIC_DM_NMI:
+		result = 1;
+		kvm_inject_nmi(vcpu);
+		kvm_vcpu_kick(vcpu);
+		break;
+
+	case APIC_DM_INIT:
+		if (!trig_mode || level) {
+			result = 1;
+			/* assumes that there are only KVM_APIC_INIT/SIPI */
+			apic->pending_events = (1UL << KVM_APIC_INIT);
+			/* make sure pending_events is visible before sending
+			 * the request */
+			smp_wmb();
+			kvm_make_request(KVM_REQ_EVENT, vcpu);
+			kvm_vcpu_kick(vcpu);
+		} else {
+			apic_debug("Ignoring de-assert INIT to vcpu %d\n",
+				   vcpu->vcpu_id);
+		}
+		break;
+
+	case APIC_DM_STARTUP:
+		apic_debug("SIPI to vcpu %d vector 0x%02x\n",
+			   vcpu->vcpu_id, vector);
+		result = 1;
+		apic->sipi_vector = vector;
+		/* make sure sipi_vector is visible for the receiver */
+		smp_wmb();
+		set_bit(KVM_APIC_SIPI, &apic->pending_events);
+		kvm_make_request(KVM_REQ_EVENT, vcpu);
+		kvm_vcpu_kick(vcpu);
+		break;
+
+	case APIC_DM_EXTINT:
+		/*
+		 * Should only be called by kvm_apic_local_deliver() with LVT0,
+		 * before NMI watchdog was enabled. Already handled by
+		 * kvm_apic_accept_pic_intr().
+		 */
+		break;
+
+	default:
+		printk(KERN_ERR "TODO: unsupported delivery mode %x\n",
+		       delivery_mode);
+		break;
+	}
+	return result;
+}
+
+int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2)
+{
+	return vcpu1->arch.apic_arb_prio - vcpu2->arch.apic_arb_prio;
+}
+
+static void kvm_ioapic_send_eoi(struct kvm_lapic *apic, int vector)
+{
+	if (kvm_ioapic_handles_vector(apic->vcpu->kvm, vector)) {
+		int trigger_mode;
+		if (apic_test_vector(vector, apic->regs + APIC_TMR))
+			trigger_mode = IOAPIC_LEVEL_TRIG;
+		else
+			trigger_mode = IOAPIC_EDGE_TRIG;
+		kvm_ioapic_update_eoi(apic->vcpu, vector, trigger_mode);
+	}
+}
+
+static int apic_set_eoi(struct kvm_lapic *apic)
+{
+	int vector = apic_find_highest_isr(apic);
+
+	trace_kvm_eoi(apic, vector);
+
+	/*
+	 * Not every write EOI will has corresponding ISR,
+	 * one example is when Kernel check timer on setup_IO_APIC
+	 */
+	if (vector == -1)
+		return vector;
+
+	apic_clear_isr(vector, apic);
+	apic_update_ppr(apic);
+
+	kvm_ioapic_send_eoi(apic, vector);
+	kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
+	return vector;
+}
+
+/*
+ * this interface assumes a trap-like exit, which has already finished
+ * desired side effect including vISR and vPPR update.
+ */
+void kvm_apic_set_eoi_accelerated(struct kvm_vcpu *vcpu, int vector)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	trace_kvm_eoi(apic, vector);
+
+	kvm_ioapic_send_eoi(apic, vector);
+	kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
+}
+EXPORT_SYMBOL_GPL(kvm_apic_set_eoi_accelerated);
+
+static void apic_send_ipi(struct kvm_lapic *apic)
+{
+	u32 icr_low = kvm_apic_get_reg(apic, APIC_ICR);
+	u32 icr_high = kvm_apic_get_reg(apic, APIC_ICR2);
+	struct kvm_lapic_irq irq;
+
+	irq.vector = icr_low & APIC_VECTOR_MASK;
+	irq.delivery_mode = icr_low & APIC_MODE_MASK;
+	irq.dest_mode = icr_low & APIC_DEST_MASK;
+	irq.level = icr_low & APIC_INT_ASSERT;
+	irq.trig_mode = icr_low & APIC_INT_LEVELTRIG;
+	irq.shorthand = icr_low & APIC_SHORT_MASK;
+	if (apic_x2apic_mode(apic))
+		irq.dest_id = icr_high;
+	else
+		irq.dest_id = GET_APIC_DEST_FIELD(icr_high);
+
+	trace_kvm_apic_ipi(icr_low, irq.dest_id);
+
+	apic_debug("icr_high 0x%x, icr_low 0x%x, "
+		   "short_hand 0x%x, dest 0x%x, trig_mode 0x%x, level 0x%x, "
+		   "dest_mode 0x%x, delivery_mode 0x%x, vector 0x%x\n",
+		   icr_high, icr_low, irq.shorthand, irq.dest_id,
+		   irq.trig_mode, irq.level, irq.dest_mode, irq.delivery_mode,
+		   irq.vector);
+
+	kvm_irq_delivery_to_apic(apic->vcpu->kvm, apic, &irq, NULL);
+}
+
+static u32 apic_get_tmcct(struct kvm_lapic *apic)
+{
+	ktime_t remaining;
+	s64 ns;
+	u32 tmcct;
+
+	ASSERT(apic != NULL);
+
+	/* if initial count is 0, current count should also be 0 */
+	if (kvm_apic_get_reg(apic, APIC_TMICT) == 0 ||
+		apic->lapic_timer.period == 0)
+		return 0;
+
+	remaining = hrtimer_get_remaining(&apic->lapic_timer.timer);
+	if (ktime_to_ns(remaining) < 0)
+		remaining = ktime_set(0, 0);
+
+	ns = mod_64(ktime_to_ns(remaining), apic->lapic_timer.period);
+	tmcct = div64_u64(ns,
+			 (APIC_BUS_CYCLE_NS * apic->divide_count));
+
+	return tmcct;
+}
+
+static void __report_tpr_access(struct kvm_lapic *apic, bool write)
+{
+	struct kvm_vcpu *vcpu = apic->vcpu;
+	struct kvm_run *run = vcpu->run;
+
+	kvm_make_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu);
+	run->tpr_access.rip = kvm_rip_read(vcpu);
+	run->tpr_access.is_write = write;
+}
+
+static inline void report_tpr_access(struct kvm_lapic *apic, bool write)
+{
+	if (apic->vcpu->arch.tpr_access_reporting)
+		__report_tpr_access(apic, write);
+}
+
+static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset)
+{
+	u32 val = 0;
+
+	if (offset >= LAPIC_MMIO_LENGTH)
+		return 0;
+
+	switch (offset) {
+	case APIC_ID:
+		if (apic_x2apic_mode(apic))
+			val = kvm_apic_id(apic);
+		else
+			val = kvm_apic_id(apic) << 24;
+		break;
+	case APIC_ARBPRI:
+		apic_debug("Access APIC ARBPRI register which is for P6\n");
+		break;
+
+	case APIC_TMCCT:	/* Timer CCR */
+		if (apic_lvtt_tscdeadline(apic))
+			return 0;
+
+		val = apic_get_tmcct(apic);
+		break;
+	case APIC_PROCPRI:
+		apic_update_ppr(apic);
+		val = kvm_apic_get_reg(apic, offset);
+		break;
+	case APIC_TASKPRI:
+		report_tpr_access(apic, false);
+		/* fall thru */
+	default:
+		val = kvm_apic_get_reg(apic, offset);
+		break;
+	}
+
+	return val;
+}
+
+static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev)
+{
+	return container_of(dev, struct kvm_lapic, dev);
+}
+
+static int apic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
+		void *data)
+{
+	unsigned char alignment = offset & 0xf;
+	u32 result;
+	/* this bitmask has a bit cleared for each reserved register */
+	static const u64 rmask = 0x43ff01ffffffe70cULL;
+
+	if ((alignment + len) > 4) {
+		apic_debug("KVM_APIC_READ: alignment error %x %d\n",
+			   offset, len);
+		return 1;
+	}
+
+	if (offset > 0x3f0 || !(rmask & (1ULL << (offset >> 4)))) {
+		apic_debug("KVM_APIC_READ: read reserved register %x\n",
+			   offset);
+		return 1;
+	}
+
+	result = __apic_read(apic, offset & ~0xf);
+
+	trace_kvm_apic_read(offset, result);
+
+	switch (len) {
+	case 1:
+	case 2:
+	case 4:
+		memcpy(data, (char *)&result + alignment, len);
+		break;
+	default:
+		printk(KERN_ERR "Local APIC read with len = %x, "
+		       "should be 1,2, or 4 instead\n", len);
+		break;
+	}
+	return 0;
+}
+
+static int apic_mmio_in_range(struct kvm_lapic *apic, gpa_t addr)
+{
+	return kvm_apic_hw_enabled(apic) &&
+	    addr >= apic->base_address &&
+	    addr < apic->base_address + LAPIC_MMIO_LENGTH;
+}
+
+static int apic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
+			   gpa_t address, int len, void *data)
+{
+	struct kvm_lapic *apic = to_lapic(this);
+	u32 offset = address - apic->base_address;
+
+	if (!apic_mmio_in_range(apic, address))
+		return -EOPNOTSUPP;
+
+	apic_reg_read(apic, offset, len, data);
+
+	return 0;
+}
+
+static void update_divide_count(struct kvm_lapic *apic)
+{
+	u32 tmp1, tmp2, tdcr;
+
+	tdcr = kvm_apic_get_reg(apic, APIC_TDCR);
+	tmp1 = tdcr & 0xf;
+	tmp2 = ((tmp1 & 0x3) | ((tmp1 & 0x8) >> 1)) + 1;
+	apic->divide_count = 0x1 << (tmp2 & 0x7);
+
+	apic_debug("timer divide count is 0x%x\n",
+				   apic->divide_count);
+}
+
+static void apic_update_lvtt(struct kvm_lapic *apic)
+{
+	u32 timer_mode = kvm_apic_get_reg(apic, APIC_LVTT) &
+			apic->lapic_timer.timer_mode_mask;
+
+	if (apic->lapic_timer.timer_mode != timer_mode) {
+		apic->lapic_timer.timer_mode = timer_mode;
+		hrtimer_cancel(&apic->lapic_timer.timer);
+	}
+}
+
+static void apic_timer_expired(struct kvm_lapic *apic)
+{
+	struct kvm_vcpu *vcpu = apic->vcpu;
+	struct swait_head *q = &vcpu->wq;
+	struct kvm_timer *ktimer = &apic->lapic_timer;
+
+	if (atomic_read(&apic->lapic_timer.pending))
+		return;
+
+	atomic_inc(&apic->lapic_timer.pending);
+	kvm_set_pending_timer(vcpu);
+
+	if (swaitqueue_active(q))
+		swait_wake_interruptible(q);
+
+	if (apic_lvtt_tscdeadline(apic))
+		ktimer->expired_tscdeadline = ktimer->tscdeadline;
+}
+
+/*
+ * On APICv, this test will cause a busy wait
+ * during a higher-priority task.
+ */
+
+static bool lapic_timer_int_injected(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u32 reg = kvm_apic_get_reg(apic, APIC_LVTT);
+
+	if (kvm_apic_hw_enabled(apic)) {
+		int vec = reg & APIC_VECTOR_MASK;
+		void *bitmap = apic->regs + APIC_ISR;
+
+		if (kvm_x86_ops->deliver_posted_interrupt)
+			bitmap = apic->regs + APIC_IRR;
+
+		if (apic_test_vector(vec, bitmap))
+			return true;
+	}
+	return false;
+}
+
+void wait_lapic_expire(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u64 guest_tsc, tsc_deadline;
+
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return;
+
+	if (apic->lapic_timer.expired_tscdeadline == 0)
+		return;
+
+	if (!lapic_timer_int_injected(vcpu))
+		return;
+
+	tsc_deadline = apic->lapic_timer.expired_tscdeadline;
+	apic->lapic_timer.expired_tscdeadline = 0;
+	guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
+	trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline);
+
+	/* __delay is delay_tsc whenever the hardware has TSC, thus always.  */
+	if (guest_tsc < tsc_deadline)
+		__delay(tsc_deadline - guest_tsc);
+}
+
+static enum hrtimer_restart apic_timer_fn(struct hrtimer *data);
+
+static void __apic_timer_expired(struct hrtimer *data)
+{
+	int ret, i = 0;
+	enum hrtimer_restart r;
+	struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
+
+	r = apic_timer_fn(data);
+
+	if (r == HRTIMER_RESTART) {
+		do {
+			ret = hrtimer_start_expires(data, HRTIMER_MODE_ABS);
+			if (ret == -ETIME)
+				hrtimer_add_expires_ns(&ktimer->timer,
+						       ktimer->period);
+			i++;
+		} while (ret == -ETIME && i < 10);
+
+		if (ret == -ETIME) {
+			printk_once(KERN_ERR "%s: failed to reprogram timer\n",
+				    __func__);
+			WARN_ON_ONCE(1);
+		}
+	}
+}
+
+static void start_apic_timer(struct kvm_lapic *apic)
+{
+	int ret;
+	ktime_t now;
+
+	atomic_set(&apic->lapic_timer.pending, 0);
+
+	if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) {
+		/* lapic timer in oneshot or periodic mode */
+		now = apic->lapic_timer.timer.base->get_time();
+		apic->lapic_timer.period = (u64)kvm_apic_get_reg(apic, APIC_TMICT)
+			    * APIC_BUS_CYCLE_NS * apic->divide_count;
+
+		if (!apic->lapic_timer.period)
+			return;
+		/*
+		 * Do not allow the guest to program periodic timers with small
+		 * interval, since the hrtimers are not throttled by the host
+		 * scheduler.
+		 */
+		if (apic_lvtt_period(apic)) {
+			s64 min_period = min_timer_period_us * 1000LL;
+
+			if (apic->lapic_timer.period < min_period) {
+				pr_info_ratelimited(
+				    "kvm: vcpu %i: requested %lld ns "
+				    "lapic timer period limited to %lld ns\n",
+				    apic->vcpu->vcpu_id,
+				    apic->lapic_timer.period, min_period);
+				apic->lapic_timer.period = min_period;
+			}
+		}
+
+		ret = hrtimer_start(&apic->lapic_timer.timer,
+			      ktime_add_ns(now, apic->lapic_timer.period),
+			      HRTIMER_MODE_ABS);
+		if (ret == -ETIME)
+			__apic_timer_expired(&apic->lapic_timer.timer);
+
+		apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
+			   PRIx64 ", "
+			   "timer initial count 0x%x, period %lldns, "
+			   "expire @ 0x%016" PRIx64 ".\n", __func__,
+			   APIC_BUS_CYCLE_NS, ktime_to_ns(now),
+			   kvm_apic_get_reg(apic, APIC_TMICT),
+			   apic->lapic_timer.period,
+			   ktime_to_ns(ktime_add_ns(now,
+					apic->lapic_timer.period)));
+	} else if (apic_lvtt_tscdeadline(apic)) {
+		/* lapic timer in tsc deadline mode */
+		u64 guest_tsc, tscdeadline = apic->lapic_timer.tscdeadline;
+		u64 ns = 0;
+		ktime_t expire;
+		struct kvm_vcpu *vcpu = apic->vcpu;
+		unsigned long this_tsc_khz = vcpu->arch.virtual_tsc_khz;
+		unsigned long flags;
+
+		if (unlikely(!tscdeadline || !this_tsc_khz))
+			return;
+
+		local_irq_save(flags);
+
+		now = apic->lapic_timer.timer.base->get_time();
+		guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
+		if (likely(tscdeadline > guest_tsc)) {
+			ns = (tscdeadline - guest_tsc) * 1000000ULL;
+			do_div(ns, this_tsc_khz);
+			expire = ktime_add_ns(now, ns);
+			expire = ktime_sub_ns(expire, lapic_timer_advance_ns);
+			ret = hrtimer_start(&apic->lapic_timer.timer,
+				      expire, HRTIMER_MODE_ABS);
+			if (ret == -ETIME)
+				__apic_timer_expired(&apic->lapic_timer.timer);
+		} else
+			apic_timer_expired(apic);
+
+		local_irq_restore(flags);
+	}
+}
+
+static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
+{
+	int nmi_wd_enabled = apic_lvt_nmi_mode(kvm_apic_get_reg(apic, APIC_LVT0));
+
+	if (apic_lvt_nmi_mode(lvt0_val)) {
+		if (!nmi_wd_enabled) {
+			apic_debug("Receive NMI setting on APIC_LVT0 "
+				   "for cpu %d\n", apic->vcpu->vcpu_id);
+			atomic_inc(&apic->vcpu->kvm->arch.vapics_in_nmi_mode);
+		}
+	} else if (nmi_wd_enabled)
+		atomic_dec(&apic->vcpu->kvm->arch.vapics_in_nmi_mode);
+}
+
+static int apic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
+{
+	int ret = 0;
+
+	trace_kvm_apic_write(reg, val);
+
+	switch (reg) {
+	case APIC_ID:		/* Local APIC ID */
+		if (!apic_x2apic_mode(apic))
+			kvm_apic_set_id(apic, val >> 24);
+		else
+			ret = 1;
+		break;
+
+	case APIC_TASKPRI:
+		report_tpr_access(apic, true);
+		apic_set_tpr(apic, val & 0xff);
+		break;
+
+	case APIC_EOI:
+		apic_set_eoi(apic);
+		break;
+
+	case APIC_LDR:
+		if (!apic_x2apic_mode(apic))
+			kvm_apic_set_ldr(apic, val & APIC_LDR_MASK);
+		else
+			ret = 1;
+		break;
+
+	case APIC_DFR:
+		if (!apic_x2apic_mode(apic)) {
+			apic_set_reg(apic, APIC_DFR, val | 0x0FFFFFFF);
+			recalculate_apic_map(apic->vcpu->kvm);
+		} else
+			ret = 1;
+		break;
+
+	case APIC_SPIV: {
+		u32 mask = 0x3ff;
+		if (kvm_apic_get_reg(apic, APIC_LVR) & APIC_LVR_DIRECTED_EOI)
+			mask |= APIC_SPIV_DIRECTED_EOI;
+		apic_set_spiv(apic, val & mask);
+		if (!(val & APIC_SPIV_APIC_ENABLED)) {
+			int i;
+			u32 lvt_val;
+
+			for (i = 0; i < APIC_LVT_NUM; i++) {
+				lvt_val = kvm_apic_get_reg(apic,
+						       APIC_LVTT + 0x10 * i);
+				apic_set_reg(apic, APIC_LVTT + 0x10 * i,
+					     lvt_val | APIC_LVT_MASKED);
+			}
+			apic_update_lvtt(apic);
+			atomic_set(&apic->lapic_timer.pending, 0);
+
+		}
+		break;
+	}
+	case APIC_ICR:
+		/* No delay here, so we always clear the pending bit */
+		apic_set_reg(apic, APIC_ICR, val & ~(1 << 12));
+		apic_send_ipi(apic);
+		break;
+
+	case APIC_ICR2:
+		if (!apic_x2apic_mode(apic))
+			val &= 0xff000000;
+		apic_set_reg(apic, APIC_ICR2, val);
+		break;
+
+	case APIC_LVT0:
+		apic_manage_nmi_watchdog(apic, val);
+	case APIC_LVTTHMR:
+	case APIC_LVTPC:
+	case APIC_LVT1:
+	case APIC_LVTERR:
+		/* TODO: Check vector */
+		if (!kvm_apic_sw_enabled(apic))
+			val |= APIC_LVT_MASKED;
+
+		val &= apic_lvt_mask[(reg - APIC_LVTT) >> 4];
+		apic_set_reg(apic, reg, val);
+
+		break;
+
+	case APIC_LVTT:
+		if (!kvm_apic_sw_enabled(apic))
+			val |= APIC_LVT_MASKED;
+		val &= (apic_lvt_mask[0] | apic->lapic_timer.timer_mode_mask);
+		apic_set_reg(apic, APIC_LVTT, val);
+		apic_update_lvtt(apic);
+		break;
+
+	case APIC_TMICT:
+		if (apic_lvtt_tscdeadline(apic))
+			break;
+
+		hrtimer_cancel(&apic->lapic_timer.timer);
+		apic_set_reg(apic, APIC_TMICT, val);
+		start_apic_timer(apic);
+		break;
+
+	case APIC_TDCR:
+		if (val & 4)
+			apic_debug("KVM_WRITE:TDCR %x\n", val);
+		apic_set_reg(apic, APIC_TDCR, val);
+		update_divide_count(apic);
+		break;
+
+	case APIC_ESR:
+		if (apic_x2apic_mode(apic) && val != 0) {
+			apic_debug("KVM_WRITE:ESR not zero %x\n", val);
+			ret = 1;
+		}
+		break;
+
+	case APIC_SELF_IPI:
+		if (apic_x2apic_mode(apic)) {
+			apic_reg_write(apic, APIC_ICR, 0x40000 | (val & 0xff));
+		} else
+			ret = 1;
+		break;
+	default:
+		ret = 1;
+		break;
+	}
+	if (ret)
+		apic_debug("Local APIC Write to read-only register %x\n", reg);
+	return ret;
+}
+
+static int apic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
+			    gpa_t address, int len, const void *data)
+{
+	struct kvm_lapic *apic = to_lapic(this);
+	unsigned int offset = address - apic->base_address;
+	u32 val;
+
+	if (!apic_mmio_in_range(apic, address))
+		return -EOPNOTSUPP;
+
+	/*
+	 * APIC register must be aligned on 128-bits boundary.
+	 * 32/64/128 bits registers must be accessed thru 32 bits.
+	 * Refer SDM 8.4.1
+	 */
+	if (len != 4 || (offset & 0xf)) {
+		/* Don't shout loud, $infamous_os would cause only noise. */
+		apic_debug("apic write: bad size=%d %lx\n", len, (long)address);
+		return 0;
+	}
+
+	val = *(u32*)data;
+
+	/* too common printing */
+	if (offset != APIC_EOI)
+		apic_debug("%s: offset 0x%x with length 0x%x, and value is "
+			   "0x%x\n", __func__, offset, len, val);
+
+	apic_reg_write(apic, offset & 0xff0, val);
+
+	return 0;
+}
+
+void kvm_lapic_set_eoi(struct kvm_vcpu *vcpu)
+{
+	if (kvm_vcpu_has_lapic(vcpu))
+		apic_reg_write(vcpu->arch.apic, APIC_EOI, 0);
+}
+EXPORT_SYMBOL_GPL(kvm_lapic_set_eoi);
+
+/* emulate APIC access in a trap manner */
+void kvm_apic_write_nodecode(struct kvm_vcpu *vcpu, u32 offset)
+{
+	u32 val = 0;
+
+	/* hw has done the conditional check and inst decode */
+	offset &= 0xff0;
+
+	apic_reg_read(vcpu->arch.apic, offset, 4, &val);
+
+	/* TODO: optimize to just emulate side effect w/o one more write */
+	apic_reg_write(vcpu->arch.apic, offset, val);
+}
+EXPORT_SYMBOL_GPL(kvm_apic_write_nodecode);
+
+void kvm_free_lapic(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (!vcpu->arch.apic)
+		return;
+
+	hrtimer_cancel(&apic->lapic_timer.timer);
+
+	if (!(vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE))
+		static_key_slow_dec_deferred(&apic_hw_disabled);
+
+	if (!apic->sw_enabled)
+		static_key_slow_dec_deferred(&apic_sw_disabled);
+
+	if (apic->regs)
+		free_page((unsigned long)apic->regs);
+
+	kfree(apic);
+}
+
+/*
+ *----------------------------------------------------------------------
+ * LAPIC interface
+ *----------------------------------------------------------------------
+ */
+
+u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (!kvm_vcpu_has_lapic(vcpu) || apic_lvtt_oneshot(apic) ||
+			apic_lvtt_period(apic))
+		return 0;
+
+	return apic->lapic_timer.tscdeadline;
+}
+
+void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (!kvm_vcpu_has_lapic(vcpu) || apic_lvtt_oneshot(apic) ||
+			apic_lvtt_period(apic))
+		return;
+
+	hrtimer_cancel(&apic->lapic_timer.timer);
+	apic->lapic_timer.tscdeadline = data;
+	start_apic_timer(apic);
+}
+
+void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return;
+
+	apic_set_tpr(apic, ((cr8 & 0x0f) << 4)
+		     | (kvm_apic_get_reg(apic, APIC_TASKPRI) & 4));
+}
+
+u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)
+{
+	u64 tpr;
+
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return 0;
+
+	tpr = (u64) kvm_apic_get_reg(vcpu->arch.apic, APIC_TASKPRI);
+
+	return (tpr & 0xf0) >> 4;
+}
+
+void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
+{
+	u64 old_value = vcpu->arch.apic_base;
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (!apic) {
+		value |= MSR_IA32_APICBASE_BSP;
+		vcpu->arch.apic_base = value;
+		return;
+	}
+
+	vcpu->arch.apic_base = value;
+
+	/* update jump label if enable bit changes */
+	if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) {
+		if (value & MSR_IA32_APICBASE_ENABLE)
+			static_key_slow_dec_deferred(&apic_hw_disabled);
+		else
+			static_key_slow_inc(&apic_hw_disabled.key);
+		recalculate_apic_map(vcpu->kvm);
+	}
+
+	if ((old_value ^ value) & X2APIC_ENABLE) {
+		if (value & X2APIC_ENABLE) {
+			u32 id = kvm_apic_id(apic);
+			u32 ldr = ((id >> 4) << 16) | (1 << (id & 0xf));
+			kvm_apic_set_ldr(apic, ldr);
+			kvm_x86_ops->set_virtual_x2apic_mode(vcpu, true);
+		} else
+			kvm_x86_ops->set_virtual_x2apic_mode(vcpu, false);
+	}
+
+	apic->base_address = apic->vcpu->arch.apic_base &
+			     MSR_IA32_APICBASE_BASE;
+
+	if ((value & MSR_IA32_APICBASE_ENABLE) &&
+	     apic->base_address != APIC_DEFAULT_PHYS_BASE)
+		pr_warn_once("APIC base relocation is unsupported by KVM");
+
+	/* with FSB delivery interrupt, we can restart APIC functionality */
+	apic_debug("apic base msr is 0x%016" PRIx64 ", and base address is "
+		   "0x%lx.\n", apic->vcpu->arch.apic_base, apic->base_address);
+
+}
+
+void kvm_lapic_reset(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic;
+	int i;
+
+	apic_debug("%s\n", __func__);
+
+	ASSERT(vcpu);
+	apic = vcpu->arch.apic;
+	ASSERT(apic != NULL);
+
+	/* Stop the timer in case it's a reset to an active apic */
+	hrtimer_cancel(&apic->lapic_timer.timer);
+
+	kvm_apic_set_id(apic, vcpu->vcpu_id);
+	kvm_apic_set_version(apic->vcpu);
+
+	for (i = 0; i < APIC_LVT_NUM; i++)
+		apic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED);
+	apic_update_lvtt(apic);
+	apic_set_reg(apic, APIC_LVT0,
+		     SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT));
+
+	apic_set_reg(apic, APIC_DFR, 0xffffffffU);
+	apic_set_spiv(apic, 0xff);
+	apic_set_reg(apic, APIC_TASKPRI, 0);
+	kvm_apic_set_ldr(apic, 0);
+	apic_set_reg(apic, APIC_ESR, 0);
+	apic_set_reg(apic, APIC_ICR, 0);
+	apic_set_reg(apic, APIC_ICR2, 0);
+	apic_set_reg(apic, APIC_TDCR, 0);
+	apic_set_reg(apic, APIC_TMICT, 0);
+	for (i = 0; i < 8; i++) {
+		apic_set_reg(apic, APIC_IRR + 0x10 * i, 0);
+		apic_set_reg(apic, APIC_ISR + 0x10 * i, 0);
+		apic_set_reg(apic, APIC_TMR + 0x10 * i, 0);
+	}
+	apic->irr_pending = kvm_apic_vid_enabled(vcpu->kvm);
+	apic->isr_count = kvm_x86_ops->hwapic_isr_update ? 1 : 0;
+	apic->highest_isr_cache = -1;
+	update_divide_count(apic);
+	atomic_set(&apic->lapic_timer.pending, 0);
+	if (kvm_vcpu_is_bsp(vcpu))
+		kvm_lapic_set_base(vcpu,
+				vcpu->arch.apic_base | MSR_IA32_APICBASE_BSP);
+	vcpu->arch.pv_eoi.msr_val = 0;
+	apic_update_ppr(apic);
+
+	vcpu->arch.apic_arb_prio = 0;
+	vcpu->arch.apic_attention = 0;
+
+	apic_debug("%s: vcpu=%p, id=%d, base_msr="
+		   "0x%016" PRIx64 ", base_address=0x%0lx.\n", __func__,
+		   vcpu, kvm_apic_id(apic),
+		   vcpu->arch.apic_base, apic->base_address);
+}
+
+/*
+ *----------------------------------------------------------------------
+ * timer interface
+ *----------------------------------------------------------------------
+ */
+
+static bool lapic_is_periodic(struct kvm_lapic *apic)
+{
+	return apic_lvtt_period(apic);
+}
+
+int apic_has_pending_timer(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (kvm_vcpu_has_lapic(vcpu) && apic_enabled(apic) &&
+			apic_lvt_enabled(apic, APIC_LVTT))
+		return atomic_read(&apic->lapic_timer.pending);
+
+	return 0;
+}
+
+int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type)
+{
+	u32 reg = kvm_apic_get_reg(apic, lvt_type);
+	int vector, mode, trig_mode;
+
+	if (kvm_apic_hw_enabled(apic) && !(reg & APIC_LVT_MASKED)) {
+		vector = reg & APIC_VECTOR_MASK;
+		mode = reg & APIC_MODE_MASK;
+		trig_mode = reg & APIC_LVT_LEVEL_TRIGGER;
+		return __apic_accept_irq(apic, mode, vector, 1, trig_mode,
+					NULL);
+	}
+	return 0;
+}
+
+void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (apic)
+		kvm_apic_local_deliver(apic, APIC_LVT0);
+}
+
+static const struct kvm_io_device_ops apic_mmio_ops = {
+	.read     = apic_mmio_read,
+	.write    = apic_mmio_write,
+};
+
+static enum hrtimer_restart apic_timer_fn(struct hrtimer *data)
+{
+	struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
+	struct kvm_lapic *apic = container_of(ktimer, struct kvm_lapic, lapic_timer);
+
+	apic_timer_expired(apic);
+
+	if (lapic_is_periodic(apic)) {
+		hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
+		return HRTIMER_RESTART;
+	} else
+		return HRTIMER_NORESTART;
+}
+
+int kvm_create_lapic(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic;
+
+	ASSERT(vcpu != NULL);
+	apic_debug("apic_init %d\n", vcpu->vcpu_id);
+
+	apic = kzalloc(sizeof(*apic), GFP_KERNEL);
+	if (!apic)
+		goto nomem;
+
+	vcpu->arch.apic = apic;
+
+	apic->regs = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!apic->regs) {
+		printk(KERN_ERR "malloc apic regs error for vcpu %x\n",
+		       vcpu->vcpu_id);
+		goto nomem_free_apic;
+	}
+	apic->vcpu = vcpu;
+
+	hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_ABS);
+	apic->lapic_timer.timer.function = apic_timer_fn;
+	apic->lapic_timer.timer.irqsafe = 1;
+
+	/*
+	 * APIC is created enabled. This will prevent kvm_lapic_set_base from
+	 * thinking that APIC satet has changed.
+	 */
+	vcpu->arch.apic_base = MSR_IA32_APICBASE_ENABLE;
+	kvm_lapic_set_base(vcpu,
+			APIC_DEFAULT_PHYS_BASE | MSR_IA32_APICBASE_ENABLE);
+
+	static_key_slow_inc(&apic_sw_disabled.key); /* sw disabled at reset */
+	kvm_lapic_reset(vcpu);
+	kvm_iodevice_init(&apic->dev, &apic_mmio_ops);
+
+	return 0;
+nomem_free_apic:
+	kfree(apic);
+nomem:
+	return -ENOMEM;
+}
+
+int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	int highest_irr;
+
+	if (!kvm_vcpu_has_lapic(vcpu) || !apic_enabled(apic))
+		return -1;
+
+	apic_update_ppr(apic);
+	highest_irr = apic_find_highest_irr(apic);
+	if ((highest_irr == -1) ||
+	    ((highest_irr & 0xF0) <= kvm_apic_get_reg(apic, APIC_PROCPRI)))
+		return -1;
+	return highest_irr;
+}
+
+int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu)
+{
+	u32 lvt0 = kvm_apic_get_reg(vcpu->arch.apic, APIC_LVT0);
+	int r = 0;
+
+	if (!kvm_apic_hw_enabled(vcpu->arch.apic))
+		r = 1;
+	if ((lvt0 & APIC_LVT_MASKED) == 0 &&
+	    GET_APIC_DELIVERY_MODE(lvt0) == APIC_MODE_EXTINT)
+		r = 1;
+	return r;
+}
+
+void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return;
+
+	if (atomic_read(&apic->lapic_timer.pending) > 0) {
+		kvm_apic_local_deliver(apic, APIC_LVTT);
+		if (apic_lvtt_tscdeadline(apic))
+			apic->lapic_timer.tscdeadline = 0;
+		atomic_set(&apic->lapic_timer.pending, 0);
+	}
+}
+
+int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu)
+{
+	int vector = kvm_apic_has_interrupt(vcpu);
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (vector == -1)
+		return -1;
+
+	/*
+	 * We get here even with APIC virtualization enabled, if doing
+	 * nested virtualization and L1 runs with the "acknowledge interrupt
+	 * on exit" mode.  Then we cannot inject the interrupt via RVI,
+	 * because the process would deliver it through the IDT.
+	 */
+
+	apic_set_isr(vector, apic);
+	apic_update_ppr(apic);
+	apic_clear_irr(vector, apic);
+	return vector;
+}
+
+void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
+		struct kvm_lapic_state *s)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	kvm_lapic_set_base(vcpu, vcpu->arch.apic_base);
+	/* set SPIV separately to get count of SW disabled APICs right */
+	apic_set_spiv(apic, *((u32 *)(s->regs + APIC_SPIV)));
+	memcpy(vcpu->arch.apic->regs, s->regs, sizeof *s);
+	/* call kvm_apic_set_id() to put apic into apic_map */
+	kvm_apic_set_id(apic, kvm_apic_id(apic));
+	kvm_apic_set_version(vcpu);
+
+	apic_update_ppr(apic);
+	hrtimer_cancel(&apic->lapic_timer.timer);
+	apic_update_lvtt(apic);
+	apic_manage_nmi_watchdog(apic, kvm_apic_get_reg(apic, APIC_LVT0));
+	update_divide_count(apic);
+	start_apic_timer(apic);
+	apic->irr_pending = true;
+	apic->isr_count = kvm_x86_ops->hwapic_isr_update ?
+				1 : count_vectors(apic->regs + APIC_ISR);
+	apic->highest_isr_cache = -1;
+	if (kvm_x86_ops->hwapic_irr_update)
+		kvm_x86_ops->hwapic_irr_update(vcpu,
+				apic_find_highest_irr(apic));
+	if (unlikely(kvm_x86_ops->hwapic_isr_update))
+		kvm_x86_ops->hwapic_isr_update(vcpu->kvm,
+				apic_find_highest_isr(apic));
+	kvm_make_request(KVM_REQ_EVENT, vcpu);
+	kvm_rtc_eoi_tracking_restore_one(vcpu);
+}
+
+void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
+{
+	struct hrtimer *timer;
+
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return;
+
+	timer = &vcpu->arch.apic->lapic_timer.timer;
+	if (hrtimer_cancel(timer))
+		if (hrtimer_start_expires(timer, HRTIMER_MODE_ABS) == -ETIME)
+			__apic_timer_expired(timer);
+}
+
+/*
+ * apic_sync_pv_eoi_from_guest - called on vmexit or cancel interrupt
+ *
+ * Detect whether guest triggered PV EOI since the
+ * last entry. If yes, set EOI on guests's behalf.
+ * Clear PV EOI in guest memory in any case.
+ */
+static void apic_sync_pv_eoi_from_guest(struct kvm_vcpu *vcpu,
+					struct kvm_lapic *apic)
+{
+	bool pending;
+	int vector;
+	/*
+	 * PV EOI state is derived from KVM_APIC_PV_EOI_PENDING in host
+	 * and KVM_PV_EOI_ENABLED in guest memory as follows:
+	 *
+	 * KVM_APIC_PV_EOI_PENDING is unset:
+	 * 	-> host disabled PV EOI.
+	 * KVM_APIC_PV_EOI_PENDING is set, KVM_PV_EOI_ENABLED is set:
+	 * 	-> host enabled PV EOI, guest did not execute EOI yet.
+	 * KVM_APIC_PV_EOI_PENDING is set, KVM_PV_EOI_ENABLED is unset:
+	 * 	-> host enabled PV EOI, guest executed EOI.
+	 */
+	BUG_ON(!pv_eoi_enabled(vcpu));
+	pending = pv_eoi_get_pending(vcpu);
+	/*
+	 * Clear pending bit in any case: it will be set again on vmentry.
+	 * While this might not be ideal from performance point of view,
+	 * this makes sure pv eoi is only enabled when we know it's safe.
+	 */
+	pv_eoi_clr_pending(vcpu);
+	if (pending)
+		return;
+	vector = apic_set_eoi(apic);
+	trace_kvm_pv_eoi(apic, vector);
+}
+
+void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
+{
+	u32 data;
+
+	if (test_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention))
+		apic_sync_pv_eoi_from_guest(vcpu, vcpu->arch.apic);
+
+	if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
+		return;
+
+	kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data,
+				sizeof(u32));
+
+	apic_set_tpr(vcpu->arch.apic, data & 0xff);
+}
+
+/*
+ * apic_sync_pv_eoi_to_guest - called before vmentry
+ *
+ * Detect whether it's safe to enable PV EOI and
+ * if yes do so.
+ */
+static void apic_sync_pv_eoi_to_guest(struct kvm_vcpu *vcpu,
+					struct kvm_lapic *apic)
+{
+	if (!pv_eoi_enabled(vcpu) ||
+	    /* IRR set or many bits in ISR: could be nested. */
+	    apic->irr_pending ||
+	    /* Cache not set: could be safe but we don't bother. */
+	    apic->highest_isr_cache == -1 ||
+	    /* Need EOI to update ioapic. */
+	    kvm_ioapic_handles_vector(vcpu->kvm, apic->highest_isr_cache)) {
+		/*
+		 * PV EOI was disabled by apic_sync_pv_eoi_from_guest
+		 * so we need not do anything here.
+		 */
+		return;
+	}
+
+	pv_eoi_set_pending(apic->vcpu);
+}
+
+void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
+{
+	u32 data, tpr;
+	int max_irr, max_isr;
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	apic_sync_pv_eoi_to_guest(vcpu, apic);
+
+	if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
+		return;
+
+	tpr = kvm_apic_get_reg(apic, APIC_TASKPRI) & 0xff;
+	max_irr = apic_find_highest_irr(apic);
+	if (max_irr < 0)
+		max_irr = 0;
+	max_isr = apic_find_highest_isr(apic);
+	if (max_isr < 0)
+		max_isr = 0;
+	data = (tpr & 0xff) | ((max_isr & 0xf0) << 8) | (max_irr << 24);
+
+	kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data,
+				sizeof(u32));
+}
+
+int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
+{
+	if (vapic_addr) {
+		if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
+					&vcpu->arch.apic->vapic_cache,
+					vapic_addr, sizeof(u32)))
+			return -EINVAL;
+		__set_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention);
+	} else {
+		__clear_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention);
+	}
+
+	vcpu->arch.apic->vapic_addr = vapic_addr;
+	return 0;
+}
+
+int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u32 reg = (msr - APIC_BASE_MSR) << 4;
+
+	if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic))
+		return 1;
+
+	if (reg == APIC_ICR2)
+		return 1;
+
+	/* if this is ICR write vector before command */
+	if (reg == APIC_ICR)
+		apic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
+	return apic_reg_write(apic, reg, (u32)data);
+}
+
+int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u32 reg = (msr - APIC_BASE_MSR) << 4, low, high = 0;
+
+	if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic))
+		return 1;
+
+	if (reg == APIC_DFR || reg == APIC_ICR2) {
+		apic_debug("KVM_APIC_READ: read x2apic reserved register %x\n",
+			   reg);
+		return 1;
+	}
+
+	if (apic_reg_read(apic, reg, 4, &low))
+		return 1;
+	if (reg == APIC_ICR)
+		apic_reg_read(apic, APIC_ICR2, 4, &high);
+
+	*data = (((u64)high) << 32) | low;
+
+	return 0;
+}
+
+int kvm_hv_vapic_msr_write(struct kvm_vcpu *vcpu, u32 reg, u64 data)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return 1;
+
+	/* if this is ICR write vector before command */
+	if (reg == APIC_ICR)
+		apic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
+	return apic_reg_write(apic, reg, (u32)data);
+}
+
+int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u32 low, high = 0;
+
+	if (!kvm_vcpu_has_lapic(vcpu))
+		return 1;
+
+	if (apic_reg_read(apic, reg, 4, &low))
+		return 1;
+	if (reg == APIC_ICR)
+		apic_reg_read(apic, APIC_ICR2, 4, &high);
+
+	*data = (((u64)high) << 32) | low;
+
+	return 0;
+}
+
+int kvm_lapic_enable_pv_eoi(struct kvm_vcpu *vcpu, u64 data)
+{
+	u64 addr = data & ~KVM_MSR_ENABLED;
+	if (!IS_ALIGNED(addr, 4))
+		return 1;
+
+	vcpu->arch.pv_eoi.msr_val = data;
+	if (!pv_eoi_enabled(vcpu))
+		return 0;
+	return kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.pv_eoi.data,
+					 addr, sizeof(u8));
+}
+
+void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u8 sipi_vector;
+	unsigned long pe;
+
+	if (!kvm_vcpu_has_lapic(vcpu) || !apic->pending_events)
+		return;
+
+	pe = xchg(&apic->pending_events, 0);
+
+	if (test_bit(KVM_APIC_INIT, &pe)) {
+		kvm_lapic_reset(vcpu);
+		kvm_vcpu_reset(vcpu);
+		if (kvm_vcpu_is_bsp(apic->vcpu))
+			vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+		else
+			vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
+	}
+	if (test_bit(KVM_APIC_SIPI, &pe) &&
+	    vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
+		/* evaluate pending_events before reading the vector */
+		smp_rmb();
+		sipi_vector = apic->sipi_vector;
+		apic_debug("vcpu %d received sipi with vector # %x\n",
+			 vcpu->vcpu_id, sipi_vector);
+		kvm_vcpu_deliver_sipi_vector(vcpu, sipi_vector);
+		vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+	}
+}
+
+void kvm_lapic_init(void)
+{
+	/* do not patch jump label more than once per second */
+	jump_label_rate_limit(&apic_hw_disabled, HZ);
+	jump_label_rate_limit(&apic_sw_disabled, HZ);
+}