Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3316 insertions, 0 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
new file mode 100644
index 0000000000..245b20973c
--- /dev/null
+++ b/arch/x86/kvm/lapic.c
@@ -0,0 +1,3316 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * 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.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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/export.h>
+#include <linux/math64.h>
+#include <linux/slab.h>
+#include <asm/processor.h>
+#include <asm/mce.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 "ioapic.h"
+#include "trace.h"
+#include "x86.h"
+#include "cpuid.h"
+#include "hyperv.h"
+#include "smm.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
+
+/* 14 is the version for Xeon and Pentium 8.4.8*/
+#define APIC_VERSION			0x14UL
+#define LAPIC_MMIO_LENGTH		(1 << 12)
+/* followed define is not in apicdef.h */
+#define MAX_APIC_VECTOR			256
+#define APIC_VECTORS_PER_REG		32
+
+static bool lapic_timer_advance_dynamic __read_mostly;
+#define LAPIC_TIMER_ADVANCE_ADJUST_MIN	100	/* clock cycles */
+#define LAPIC_TIMER_ADVANCE_ADJUST_MAX	10000	/* clock cycles */
+#define LAPIC_TIMER_ADVANCE_NS_INIT	1000
+#define LAPIC_TIMER_ADVANCE_NS_MAX     5000
+/* step-by-step approximation to mitigate fluctuation */
+#define LAPIC_TIMER_ADVANCE_ADJUST_STEP 8
+static int kvm_lapic_msr_read(struct kvm_lapic *apic, u32 reg, u64 *data);
+static int kvm_lapic_msr_write(struct kvm_lapic *apic, u32 reg, u64 data);
+
+static inline void __kvm_lapic_set_reg(char *regs, int reg_off, u32 val)
+{
+	*((u32 *) (regs + reg_off)) = val;
+}
+
+static inline void kvm_lapic_set_reg(struct kvm_lapic *apic, int reg_off, u32 val)
+{
+	__kvm_lapic_set_reg(apic->regs, reg_off, val);
+}
+
+static __always_inline u64 __kvm_lapic_get_reg64(char *regs, int reg)
+{
+	BUILD_BUG_ON(reg != APIC_ICR);
+	return *((u64 *) (regs + reg));
+}
+
+static __always_inline u64 kvm_lapic_get_reg64(struct kvm_lapic *apic, int reg)
+{
+	return __kvm_lapic_get_reg64(apic->regs, reg);
+}
+
+static __always_inline void __kvm_lapic_set_reg64(char *regs, int reg, u64 val)
+{
+	BUILD_BUG_ON(reg != APIC_ICR);
+	*((u64 *) (regs + reg)) = val;
+}
+
+static __always_inline void kvm_lapic_set_reg64(struct kvm_lapic *apic,
+						int reg, u64 val)
+{
+	__kvm_lapic_set_reg64(apic->regs, reg, 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 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));
+}
+
+__read_mostly DEFINE_STATIC_KEY_DEFERRED_FALSE(apic_hw_disabled, HZ);
+__read_mostly DEFINE_STATIC_KEY_DEFERRED_FALSE(apic_sw_disabled, HZ);
+
+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 u32 kvm_x2apic_id(struct kvm_lapic *apic)
+{
+	return apic->vcpu->vcpu_id;
+}
+
+static bool kvm_can_post_timer_interrupt(struct kvm_vcpu *vcpu)
+{
+	return pi_inject_timer && kvm_vcpu_apicv_active(vcpu) &&
+		(kvm_mwait_in_guest(vcpu->kvm) || kvm_hlt_in_guest(vcpu->kvm));
+}
+
+bool kvm_can_use_hv_timer(struct kvm_vcpu *vcpu)
+{
+	return kvm_x86_ops.set_hv_timer
+	       && !(kvm_mwait_in_guest(vcpu->kvm) ||
+		    kvm_can_post_timer_interrupt(vcpu));
+}
+
+static bool kvm_use_posted_timer_interrupt(struct kvm_vcpu *vcpu)
+{
+	return kvm_can_post_timer_interrupt(vcpu) && vcpu->mode == IN_GUEST_MODE;
+}
+
+static inline u32 kvm_apic_calc_x2apic_ldr(u32 id)
+{
+	return ((id >> 4) << 16) | (1 << (id & 0xf));
+}
+
+static inline bool kvm_apic_map_get_logical_dest(struct kvm_apic_map *map,
+		u32 dest_id, struct kvm_lapic ***cluster, u16 *mask) {
+	switch (map->logical_mode) {
+	case KVM_APIC_MODE_SW_DISABLED:
+		/* Arbitrarily use the flat map so that @cluster isn't NULL. */
+		*cluster = map->xapic_flat_map;
+		*mask = 0;
+		return true;
+	case KVM_APIC_MODE_X2APIC: {
+		u32 offset = (dest_id >> 16) * 16;
+		u32 max_apic_id = map->max_apic_id;
+
+		if (offset <= max_apic_id) {
+			u8 cluster_size = min(max_apic_id - offset + 1, 16U);
+
+			offset = array_index_nospec(offset, map->max_apic_id + 1);
+			*cluster = &map->phys_map[offset];
+			*mask = dest_id & (0xffff >> (16 - cluster_size));
+		} else {
+			*mask = 0;
+		}
+
+		return true;
+		}
+	case KVM_APIC_MODE_XAPIC_FLAT:
+		*cluster = map->xapic_flat_map;
+		*mask = dest_id & 0xff;
+		return true;
+	case KVM_APIC_MODE_XAPIC_CLUSTER:
+		*cluster = map->xapic_cluster_map[(dest_id >> 4) & 0xf];
+		*mask = dest_id & 0xf;
+		return true;
+	case KVM_APIC_MODE_MAP_DISABLED:
+		return false;
+	default:
+		WARN_ON_ONCE(1);
+		return false;
+	}
+}
+
+static void kvm_apic_map_free(struct rcu_head *rcu)
+{
+	struct kvm_apic_map *map = container_of(rcu, struct kvm_apic_map, rcu);
+
+	kvfree(map);
+}
+
+static int kvm_recalculate_phys_map(struct kvm_apic_map *new,
+				    struct kvm_vcpu *vcpu,
+				    bool *xapic_id_mismatch)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u32 x2apic_id = kvm_x2apic_id(apic);
+	u32 xapic_id = kvm_xapic_id(apic);
+	u32 physical_id;
+
+	/*
+	 * For simplicity, KVM always allocates enough space for all possible
+	 * xAPIC IDs.  Yell, but don't kill the VM, as KVM can continue on
+	 * without the optimized map.
+	 */
+	if (WARN_ON_ONCE(xapic_id > new->max_apic_id))
+		return -EINVAL;
+
+	/*
+	 * Bail if a vCPU was added and/or enabled its APIC between allocating
+	 * the map and doing the actual calculations for the map.  Note, KVM
+	 * hardcodes the x2APIC ID to vcpu_id, i.e. there's no TOCTOU bug if
+	 * the compiler decides to reload x2apic_id after this check.
+	 */
+	if (x2apic_id > new->max_apic_id)
+		return -E2BIG;
+
+	/*
+	 * Deliberately truncate the vCPU ID when detecting a mismatched APIC
+	 * ID to avoid false positives if the vCPU ID, i.e. x2APIC ID, is a
+	 * 32-bit value.  Any unwanted aliasing due to truncation results will
+	 * be detected below.
+	 */
+	if (!apic_x2apic_mode(apic) && xapic_id != (u8)vcpu->vcpu_id)
+		*xapic_id_mismatch = true;
+
+	/*
+	 * Apply KVM's hotplug hack if userspace has enable 32-bit APIC IDs.
+	 * Allow sending events to vCPUs by their x2APIC ID even if the target
+	 * vCPU is in legacy xAPIC mode, and silently ignore aliased xAPIC IDs
+	 * (the x2APIC ID is truncated to 8 bits, causing IDs > 0xff to wrap
+	 * and collide).
+	 *
+	 * Honor the architectural (and KVM's non-optimized) behavior if
+	 * userspace has not enabled 32-bit x2APIC IDs.  Each APIC is supposed
+	 * to process messages independently.  If multiple vCPUs have the same
+	 * effective APIC ID, e.g. due to the x2APIC wrap or because the guest
+	 * manually modified its xAPIC IDs, events targeting that ID are
+	 * supposed to be recognized by all vCPUs with said ID.
+	 */
+	if (vcpu->kvm->arch.x2apic_format) {
+		/* See also kvm_apic_match_physical_addr(). */
+		if (apic_x2apic_mode(apic) || x2apic_id > 0xff)
+			new->phys_map[x2apic_id] = apic;
+
+		if (!apic_x2apic_mode(apic) && !new->phys_map[xapic_id])
+			new->phys_map[xapic_id] = apic;
+	} else {
+		/*
+		 * Disable the optimized map if the physical APIC ID is already
+		 * mapped, i.e. is aliased to multiple vCPUs.  The optimized
+		 * map requires a strict 1:1 mapping between IDs and vCPUs.
+		 */
+		if (apic_x2apic_mode(apic))
+			physical_id = x2apic_id;
+		else
+			physical_id = xapic_id;
+
+		if (new->phys_map[physical_id])
+			return -EINVAL;
+
+		new->phys_map[physical_id] = apic;
+	}
+
+	return 0;
+}
+
+static void kvm_recalculate_logical_map(struct kvm_apic_map *new,
+					struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	enum kvm_apic_logical_mode logical_mode;
+	struct kvm_lapic **cluster;
+	u16 mask;
+	u32 ldr;
+
+	if (new->logical_mode == KVM_APIC_MODE_MAP_DISABLED)
+		return;
+
+	if (!kvm_apic_sw_enabled(apic))
+		return;
+
+	ldr = kvm_lapic_get_reg(apic, APIC_LDR);
+	if (!ldr)
+		return;
+
+	if (apic_x2apic_mode(apic)) {
+		logical_mode = KVM_APIC_MODE_X2APIC;
+	} else {
+		ldr = GET_APIC_LOGICAL_ID(ldr);
+		if (kvm_lapic_get_reg(apic, APIC_DFR) == APIC_DFR_FLAT)
+			logical_mode = KVM_APIC_MODE_XAPIC_FLAT;
+		else
+			logical_mode = KVM_APIC_MODE_XAPIC_CLUSTER;
+	}
+
+	/*
+	 * To optimize logical mode delivery, all software-enabled APICs must
+	 * be configured for the same mode.
+	 */
+	if (new->logical_mode == KVM_APIC_MODE_SW_DISABLED) {
+		new->logical_mode = logical_mode;
+	} else if (new->logical_mode != logical_mode) {
+		new->logical_mode = KVM_APIC_MODE_MAP_DISABLED;
+		return;
+	}
+
+	/*
+	 * In x2APIC mode, the LDR is read-only and derived directly from the
+	 * x2APIC ID, thus is guaranteed to be addressable.  KVM reuses
+	 * kvm_apic_map.phys_map to optimize logical mode x2APIC interrupts by
+	 * reversing the LDR calculation to get cluster of APICs, i.e. no
+	 * additional work is required.
+	 */
+	if (apic_x2apic_mode(apic)) {
+		WARN_ON_ONCE(ldr != kvm_apic_calc_x2apic_ldr(kvm_x2apic_id(apic)));
+		return;
+	}
+
+	if (WARN_ON_ONCE(!kvm_apic_map_get_logical_dest(new, ldr,
+							&cluster, &mask))) {
+		new->logical_mode = KVM_APIC_MODE_MAP_DISABLED;
+		return;
+	}
+
+	if (!mask)
+		return;
+
+	ldr = ffs(mask) - 1;
+	if (!is_power_of_2(mask) || cluster[ldr])
+		new->logical_mode = KVM_APIC_MODE_MAP_DISABLED;
+	else
+		cluster[ldr] = apic;
+}
+
+/*
+ * CLEAN -> DIRTY and UPDATE_IN_PROGRESS -> DIRTY changes happen without a lock.
+ *
+ * DIRTY -> UPDATE_IN_PROGRESS and UPDATE_IN_PROGRESS -> CLEAN happen with
+ * apic_map_lock_held.
+ */
+enum {
+	CLEAN,
+	UPDATE_IN_PROGRESS,
+	DIRTY
+};
+
+void kvm_recalculate_apic_map(struct kvm *kvm)
+{
+	struct kvm_apic_map *new, *old = NULL;
+	struct kvm_vcpu *vcpu;
+	unsigned long i;
+	u32 max_id = 255; /* enough space for any xAPIC ID */
+	bool xapic_id_mismatch;
+	int r;
+
+	/* Read kvm->arch.apic_map_dirty before kvm->arch.apic_map.  */
+	if (atomic_read_acquire(&kvm->arch.apic_map_dirty) == CLEAN)
+		return;
+
+	WARN_ONCE(!irqchip_in_kernel(kvm),
+		  "Dirty APIC map without an in-kernel local APIC");
+
+	mutex_lock(&kvm->arch.apic_map_lock);
+
+retry:
+	/*
+	 * Read kvm->arch.apic_map_dirty before kvm->arch.apic_map (if clean)
+	 * or the APIC registers (if dirty).  Note, on retry the map may have
+	 * not yet been marked dirty by whatever task changed a vCPU's x2APIC
+	 * ID, i.e. the map may still show up as in-progress.  In that case
+	 * this task still needs to retry and complete its calculation.
+	 */
+	if (atomic_cmpxchg_acquire(&kvm->arch.apic_map_dirty,
+				   DIRTY, UPDATE_IN_PROGRESS) == CLEAN) {
+		/* Someone else has updated the map. */
+		mutex_unlock(&kvm->arch.apic_map_lock);
+		return;
+	}
+
+	/*
+	 * Reset the mismatch flag between attempts so that KVM does the right
+	 * thing if a vCPU changes its xAPIC ID, but do NOT reset max_id, i.e.
+	 * keep max_id strictly increasing.  Disallowing max_id from shrinking
+	 * ensures KVM won't get stuck in an infinite loop, e.g. if the vCPU
+	 * with the highest x2APIC ID is toggling its APIC on and off.
+	 */
+	xapic_id_mismatch = false;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		if (kvm_apic_present(vcpu))
+			max_id = max(max_id, kvm_x2apic_id(vcpu->arch.apic));
+
+	new = kvzalloc(sizeof(struct kvm_apic_map) +
+	                   sizeof(struct kvm_lapic *) * ((u64)max_id + 1),
+			   GFP_KERNEL_ACCOUNT);
+
+	if (!new)
+		goto out;
+
+	new->max_apic_id = max_id;
+	new->logical_mode = KVM_APIC_MODE_SW_DISABLED;
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		if (!kvm_apic_present(vcpu))
+			continue;
+
+		r = kvm_recalculate_phys_map(new, vcpu, &xapic_id_mismatch);
+		if (r) {
+			kvfree(new);
+			new = NULL;
+			if (r == -E2BIG) {
+				cond_resched();
+				goto retry;
+			}
+
+			goto out;
+		}
+
+		kvm_recalculate_logical_map(new, vcpu);
+	}
+out:
+	/*
+	 * The optimized map is effectively KVM's internal version of APICv,
+	 * and all unwanted aliasing that results in disabling the optimized
+	 * map also applies to APICv.
+	 */
+	if (!new)
+		kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED);
+	else
+		kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED);
+
+	if (!new || new->logical_mode == KVM_APIC_MODE_MAP_DISABLED)
+		kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED);
+	else
+		kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED);
+
+	if (xapic_id_mismatch)
+		kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_APIC_ID_MODIFIED);
+	else
+		kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_APIC_ID_MODIFIED);
+
+	old = rcu_dereference_protected(kvm->arch.apic_map,
+			lockdep_is_held(&kvm->arch.apic_map_lock));
+	rcu_assign_pointer(kvm->arch.apic_map, new);
+	/*
+	 * Write kvm->arch.apic_map before clearing apic->apic_map_dirty.
+	 * If another update has come in, leave it DIRTY.
+	 */
+	atomic_cmpxchg_release(&kvm->arch.apic_map_dirty,
+			       UPDATE_IN_PROGRESS, CLEAN);
+	mutex_unlock(&kvm->arch.apic_map_lock);
+
+	if (old)
+		call_rcu(&old->rcu, kvm_apic_map_free);
+
+	kvm_make_scan_ioapic_request(kvm);
+}
+
+static inline void apic_set_spiv(struct kvm_lapic *apic, u32 val)
+{
+	bool enabled = val & APIC_SPIV_APIC_ENABLED;
+
+	kvm_lapic_set_reg(apic, APIC_SPIV, val);
+
+	if (enabled != apic->sw_enabled) {
+		apic->sw_enabled = enabled;
+		if (enabled)
+			static_branch_slow_dec_deferred(&apic_sw_disabled);
+		else
+			static_branch_inc(&apic_sw_disabled.key);
+
+		atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
+	}
+
+	/* Check if there are APF page ready requests pending */
+	if (enabled)
+		kvm_make_request(KVM_REQ_APF_READY, apic->vcpu);
+}
+
+static inline void kvm_apic_set_xapic_id(struct kvm_lapic *apic, u8 id)
+{
+	kvm_lapic_set_reg(apic, APIC_ID, id << 24);
+	atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
+}
+
+static inline void kvm_apic_set_ldr(struct kvm_lapic *apic, u32 id)
+{
+	kvm_lapic_set_reg(apic, APIC_LDR, id);
+	atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
+}
+
+static inline void kvm_apic_set_dfr(struct kvm_lapic *apic, u32 val)
+{
+	kvm_lapic_set_reg(apic, APIC_DFR, val);
+	atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
+}
+
+static inline void kvm_apic_set_x2apic_id(struct kvm_lapic *apic, u32 id)
+{
+	u32 ldr = kvm_apic_calc_x2apic_ldr(id);
+
+	WARN_ON_ONCE(id != apic->vcpu->vcpu_id);
+
+	kvm_lapic_set_reg(apic, APIC_ID, id);
+	kvm_lapic_set_reg(apic, APIC_LDR, ldr);
+	atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
+}
+
+static inline int apic_lvt_enabled(struct kvm_lapic *apic, int lvt_type)
+{
+	return !(kvm_lapic_get_reg(apic, lvt_type) & APIC_LVT_MASKED);
+}
+
+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;
+}
+
+static inline bool kvm_lapic_lvt_supported(struct kvm_lapic *apic, int lvt_index)
+{
+	return apic->nr_lvt_entries > lvt_index;
+}
+
+static inline int kvm_apic_calc_nr_lvt_entries(struct kvm_vcpu *vcpu)
+{
+	return KVM_APIC_MAX_NR_LVT_ENTRIES - !(vcpu->arch.mcg_cap & MCG_CMCI_P);
+}
+
+void kvm_apic_set_version(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u32 v = 0;
+
+	if (!lapic_in_kernel(vcpu))
+		return;
+
+	v = APIC_VERSION | ((apic->nr_lvt_entries - 1) << 16);
+
+	/*
+	 * KVM emulates 82093AA datasheet (with in-kernel IOAPIC implementation)
+	 * which doesn't have EOI register; Some buggy OSes (e.g. Windows with
+	 * Hyper-V role) disable EOI broadcast in lapic not checking for IOAPIC
+	 * version first and level-triggered interrupts never get EOIed in
+	 * IOAPIC.
+	 */
+	if (guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) &&
+	    !ioapic_in_kernel(vcpu->kvm))
+		v |= APIC_LVR_DIRECTED_EOI;
+	kvm_lapic_set_reg(apic, APIC_LVR, v);
+}
+
+void kvm_apic_after_set_mcg_cap(struct kvm_vcpu *vcpu)
+{
+	int nr_lvt_entries = kvm_apic_calc_nr_lvt_entries(vcpu);
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	int i;
+
+	if (!lapic_in_kernel(vcpu) || nr_lvt_entries == apic->nr_lvt_entries)
+		return;
+
+	/* Initialize/mask any "new" LVT entries. */
+	for (i = apic->nr_lvt_entries; i < nr_lvt_entries; i++)
+		kvm_lapic_set_reg(apic, APIC_LVTx(i), APIC_LVT_MASKED);
+
+	apic->nr_lvt_entries = nr_lvt_entries;
+
+	/* The number of LVT entries is reflected in the version register. */
+	kvm_apic_set_version(vcpu);
+}
+
+static const unsigned int apic_lvt_mask[KVM_APIC_MAX_NR_LVT_ENTRIES] = {
+	[LVT_TIMER] = LVT_MASK,      /* timer mode mask added at runtime */
+	[LVT_THERMAL_MONITOR] = LVT_MASK | APIC_MODE_MASK,
+	[LVT_PERFORMANCE_COUNTER] = LVT_MASK | APIC_MODE_MASK,
+	[LVT_LINT0] = LINT_MASK,
+	[LVT_LINT1] = LINT_MASK,
+	[LVT_ERROR] = LVT_MASK,
+	[LVT_CMCI] = LVT_MASK | APIC_MODE_MASK
+};
+
+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) + 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;
+}
+
+bool __kvm_apic_update_irr(u32 *pir, void *regs, int *max_irr)
+{
+	u32 i, vec;
+	u32 pir_val, irr_val, prev_irr_val;
+	int max_updated_irr;
+
+	max_updated_irr = -1;
+	*max_irr = -1;
+
+	for (i = vec = 0; i <= 7; i++, vec += 32) {
+		u32 *p_irr = (u32 *)(regs + APIC_IRR + i * 0x10);
+
+		irr_val = *p_irr;
+		pir_val = READ_ONCE(pir[i]);
+
+		if (pir_val) {
+			pir_val = xchg(&pir[i], 0);
+
+			prev_irr_val = irr_val;
+			do {
+				irr_val = prev_irr_val | pir_val;
+			} while (prev_irr_val != irr_val &&
+				 !try_cmpxchg(p_irr, &prev_irr_val, irr_val));
+
+			if (prev_irr_val != irr_val)
+				max_updated_irr = __fls(irr_val ^ prev_irr_val) + vec;
+		}
+		if (irr_val)
+			*max_irr = __fls(irr_val) + vec;
+	}
+
+	return ((max_updated_irr != -1) &&
+		(max_updated_irr == *max_irr));
+}
+EXPORT_SYMBOL_GPL(__kvm_apic_update_irr);
+
+bool kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir, int *max_irr)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	bool irr_updated = __kvm_apic_update_irr(pir, apic->regs, max_irr);
+
+	if (unlikely(!apic->apicv_active && irr_updated))
+		apic->irr_pending = true;
+	return irr_updated;
+}
+EXPORT_SYMBOL_GPL(kvm_apic_update_irr);
+
+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;
+
+	result = apic_search_irr(apic);
+	ASSERT(result == -1 || result >= 16);
+
+	return result;
+}
+
+static inline void apic_clear_irr(int vec, struct kvm_lapic *apic)
+{
+	if (unlikely(apic->apicv_active)) {
+		/* need to update RVI */
+		kvm_lapic_clear_vector(vec, apic->regs + APIC_IRR);
+		static_call_cond(kvm_x86_hwapic_irr_update)(apic->vcpu,
+							    apic_find_highest_irr(apic));
+	} else {
+		apic->irr_pending = false;
+		kvm_lapic_clear_vector(vec, apic->regs + APIC_IRR);
+		if (apic_search_irr(apic) != -1)
+			apic->irr_pending = true;
+	}
+}
+
+void kvm_apic_clear_irr(struct kvm_vcpu *vcpu, int vec)
+{
+	apic_clear_irr(vec, vcpu->arch.apic);
+}
+EXPORT_SYMBOL_GPL(kvm_apic_clear_irr);
+
+static inline void apic_set_isr(int vec, struct kvm_lapic *apic)
+{
+	if (__apic_test_and_set_vector(vec, apic->regs + APIC_ISR))
+		return;
+
+	/*
+	 * With APIC virtualization enabled, all caching is disabled
+	 * because the processor can modify ISR under the hood.  Instead
+	 * just set SVI.
+	 */
+	if (unlikely(apic->apicv_active))
+		static_call_cond(kvm_x86_hwapic_isr_update)(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)
+{
+	if (!__apic_test_and_clear_vector(vec, apic->regs + APIC_ISR))
+		return;
+
+	/*
+	 * 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(apic->apicv_active))
+		static_call_cond(kvm_x86_hwapic_isr_update)(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)
+{
+	/* 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.
+	 */
+	return apic_find_highest_irr(vcpu->arch.apic);
+}
+EXPORT_SYMBOL_GPL(kvm_lapic_find_highest_irr);
+
+static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
+			     int vector, int level, int trig_mode,
+			     struct dest_map *dest_map);
+
+int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
+		     struct dest_map *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_send_ipi(unsigned long *ipi_bitmap, struct kvm_apic_map *map,
+			 struct kvm_lapic_irq *irq, u32 min)
+{
+	int i, count = 0;
+	struct kvm_vcpu *vcpu;
+
+	if (min > map->max_apic_id)
+		return 0;
+
+	for_each_set_bit(i, ipi_bitmap,
+		min((u32)BITS_PER_LONG, (map->max_apic_id - min + 1))) {
+		if (map->phys_map[min + i]) {
+			vcpu = map->phys_map[min + i]->vcpu;
+			count += kvm_apic_set_irq(vcpu, irq, NULL);
+		}
+	}
+
+	return count;
+}
+
+int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low,
+		    unsigned long ipi_bitmap_high, u32 min,
+		    unsigned long icr, int op_64_bit)
+{
+	struct kvm_apic_map *map;
+	struct kvm_lapic_irq irq = {0};
+	int cluster_size = op_64_bit ? 64 : 32;
+	int count;
+
+	if (icr & (APIC_DEST_MASK | APIC_SHORT_MASK))
+		return -KVM_EINVAL;
+
+	irq.vector = icr & APIC_VECTOR_MASK;
+	irq.delivery_mode = icr & APIC_MODE_MASK;
+	irq.level = (icr & APIC_INT_ASSERT) != 0;
+	irq.trig_mode = icr & APIC_INT_LEVELTRIG;
+
+	rcu_read_lock();
+	map = rcu_dereference(kvm->arch.apic_map);
+
+	count = -EOPNOTSUPP;
+	if (likely(map)) {
+		count = __pv_send_ipi(&ipi_bitmap_low, map, &irq, min);
+		min += cluster_size;
+		count += __pv_send_ipi(&ipi_bitmap_high, map, &irq, min);
+	}
+
+	rcu_read_unlock();
+	return count;
+}
+
+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 void pv_eoi_set_pending(struct kvm_vcpu *vcpu)
+{
+	if (pv_eoi_put_user(vcpu, KVM_PV_EOI_ENABLED) < 0)
+		return;
+
+	__set_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
+}
+
+static bool pv_eoi_test_and_clr_pending(struct kvm_vcpu *vcpu)
+{
+	u8 val;
+
+	if (pv_eoi_get_user(vcpu, &val) < 0)
+		return false;
+
+	val &= KVM_PV_EOI_ENABLED;
+
+	if (val && pv_eoi_put_user(vcpu, KVM_PV_EOI_DISABLED) < 0)
+		return false;
+
+	/*
+	 * 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.
+	 */
+	__clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
+
+	return val;
+}
+
+static int apic_has_interrupt_for_ppr(struct kvm_lapic *apic, u32 ppr)
+{
+	int highest_irr;
+	if (kvm_x86_ops.sync_pir_to_irr)
+		highest_irr = static_call(kvm_x86_sync_pir_to_irr)(apic->vcpu);
+	else
+		highest_irr = apic_find_highest_irr(apic);
+	if (highest_irr == -1 || (highest_irr & 0xF0) <= ppr)
+		return -1;
+	return highest_irr;
+}
+
+static bool __apic_update_ppr(struct kvm_lapic *apic, u32 *new_ppr)
+{
+	u32 tpr, isrv, ppr, old_ppr;
+	int isr;
+
+	old_ppr = kvm_lapic_get_reg(apic, APIC_PROCPRI);
+	tpr = kvm_lapic_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;
+
+	*new_ppr = ppr;
+	if (old_ppr != ppr)
+		kvm_lapic_set_reg(apic, APIC_PROCPRI, ppr);
+
+	return ppr < old_ppr;
+}
+
+static void apic_update_ppr(struct kvm_lapic *apic)
+{
+	u32 ppr;
+
+	if (__apic_update_ppr(apic, &ppr) &&
+	    apic_has_interrupt_for_ppr(apic, ppr) != -1)
+		kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
+}
+
+void kvm_apic_update_ppr(struct kvm_vcpu *vcpu)
+{
+	apic_update_ppr(vcpu->arch.apic);
+}
+EXPORT_SYMBOL_GPL(kvm_apic_update_ppr);
+
+static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr)
+{
+	kvm_lapic_set_reg(apic, APIC_TASKPRI, tpr);
+	apic_update_ppr(apic);
+}
+
+static bool kvm_apic_broadcast(struct kvm_lapic *apic, u32 mda)
+{
+	return mda == (apic_x2apic_mode(apic) ?
+			X2APIC_BROADCAST : APIC_BROADCAST);
+}
+
+static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda)
+{
+	if (kvm_apic_broadcast(apic, mda))
+		return true;
+
+	/*
+	 * Hotplug hack: Accept interrupts for vCPUs in xAPIC mode as if they
+	 * were in x2APIC mode if the target APIC ID can't be encoded as an
+	 * xAPIC ID.  This allows unique addressing of hotplugged vCPUs (which
+	 * start in xAPIC mode) with an APIC ID that is unaddressable in xAPIC
+	 * mode.  Match the x2APIC ID if and only if the target APIC ID can't
+	 * be encoded in xAPIC to avoid spurious matches against a vCPU that
+	 * changed its (addressable) xAPIC ID (which is writable).
+	 */
+	if (apic_x2apic_mode(apic) || mda > 0xff)
+		return mda == kvm_x2apic_id(apic);
+
+	return mda == kvm_xapic_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_lapic_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);
+
+	switch (kvm_lapic_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:
+		return false;
+	}
+}
+
+/* The KVM local APIC implementation has two quirks:
+ *
+ *  - Real hardware delivers interrupts destined to x2APIC ID > 0xff to LAPICs
+ *    in xAPIC mode if the "destination & 0xff" matches its xAPIC ID.
+ *    KVM doesn't do that aliasing.
+ *
+ *  - in-kernel IOAPIC messages have to be delivered directly to
+ *    x2APIC, because the kernel does not support interrupt remapping.
+ *    In order to support broadcast without interrupt remapping, x2APIC
+ *    rewrites the destination of non-IPI messages from APIC_BROADCAST
+ *    to X2APIC_BROADCAST.
+ *
+ * The broadcast quirk can be disabled with KVM_CAP_X2APIC_API.  This is
+ * important when userspace wants to use x2APIC-format MSIs, because
+ * APIC_BROADCAST (0xff) is a legal route for "cluster 0, CPUs 0-7".
+ */
+static u32 kvm_apic_mda(struct kvm_vcpu *vcpu, unsigned int dest_id,
+		struct kvm_lapic *source, struct kvm_lapic *target)
+{
+	bool ipi = source != NULL;
+
+	if (!vcpu->kvm->arch.x2apic_broadcast_quirk_disabled &&
+	    !ipi && dest_id == APIC_BROADCAST && apic_x2apic_mode(target))
+		return X2APIC_BROADCAST;
+
+	return dest_id;
+}
+
+bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
+			   int shorthand, unsigned int dest, int dest_mode)
+{
+	struct kvm_lapic *target = vcpu->arch.apic;
+	u32 mda = kvm_apic_mda(vcpu, dest, source, target);
+
+	ASSERT(target);
+	switch (shorthand) {
+	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:
+		return false;
+	}
+}
+EXPORT_SYMBOL_GPL(kvm_apic_match_dest);
+
+int kvm_vector_to_index(u32 vector, u32 dest_vcpus,
+		       const unsigned long *bitmap, u32 bitmap_size)
+{
+	u32 mod;
+	int i, idx = -1;
+
+	mod = vector % dest_vcpus;
+
+	for (i = 0; i <= mod; i++) {
+		idx = find_next_bit(bitmap, bitmap_size, idx + 1);
+		BUG_ON(idx == bitmap_size);
+	}
+
+	return idx;
+}
+
+static void kvm_apic_disabled_lapic_found(struct kvm *kvm)
+{
+	if (!kvm->arch.disabled_lapic_found) {
+		kvm->arch.disabled_lapic_found = true;
+		pr_info("Disabled LAPIC found during irq injection\n");
+	}
+}
+
+static bool kvm_apic_is_broadcast_dest(struct kvm *kvm, struct kvm_lapic **src,
+		struct kvm_lapic_irq *irq, struct kvm_apic_map *map)
+{
+	if (kvm->arch.x2apic_broadcast_quirk_disabled) {
+		if ((irq->dest_id == APIC_BROADCAST &&
+		     map->logical_mode != KVM_APIC_MODE_X2APIC))
+			return true;
+		if (irq->dest_id == X2APIC_BROADCAST)
+			return true;
+	} else {
+		bool x2apic_ipi = src && *src && apic_x2apic_mode(*src);
+		if (irq->dest_id == (x2apic_ipi ?
+		                     X2APIC_BROADCAST : APIC_BROADCAST))
+			return true;
+	}
+
+	return false;
+}
+
+/* Return true if the interrupt can be handled by using *bitmap as index mask
+ * for valid destinations in *dst array.
+ * Return false if kvm_apic_map_get_dest_lapic did nothing useful.
+ * Note: we may have zero kvm_lapic destinations when we return true, which
+ * means that the interrupt should be dropped.  In this case, *bitmap would be
+ * zero and *dst undefined.
+ */
+static inline bool kvm_apic_map_get_dest_lapic(struct kvm *kvm,
+		struct kvm_lapic **src, struct kvm_lapic_irq *irq,
+		struct kvm_apic_map *map, struct kvm_lapic ***dst,
+		unsigned long *bitmap)
+{
+	int i, lowest;
+
+	if (irq->shorthand == APIC_DEST_SELF && src) {
+		*dst = src;
+		*bitmap = 1;
+		return true;
+	} else if (irq->shorthand)
+		return false;
+
+	if (!map || kvm_apic_is_broadcast_dest(kvm, src, irq, map))
+		return false;
+
+	if (irq->dest_mode == APIC_DEST_PHYSICAL) {
+		if (irq->dest_id > map->max_apic_id) {
+			*bitmap = 0;
+		} else {
+			u32 dest_id = array_index_nospec(irq->dest_id, map->max_apic_id + 1);
+			*dst = &map->phys_map[dest_id];
+			*bitmap = 1;
+		}
+		return true;
+	}
+
+	*bitmap = 0;
+	if (!kvm_apic_map_get_logical_dest(map, irq->dest_id, dst,
+				(u16 *)bitmap))
+		return false;
+
+	if (!kvm_lowest_prio_delivery(irq))
+		return true;
+
+	if (!kvm_vector_hashing_enabled()) {
+		lowest = -1;
+		for_each_set_bit(i, bitmap, 16) {
+			if (!(*dst)[i])
+				continue;
+			if (lowest < 0)
+				lowest = i;
+			else if (kvm_apic_compare_prio((*dst)[i]->vcpu,
+						(*dst)[lowest]->vcpu) < 0)
+				lowest = i;
+		}
+	} else {
+		if (!*bitmap)
+			return true;
+
+		lowest = kvm_vector_to_index(irq->vector, hweight16(*bitmap),
+				bitmap, 16);
+
+		if (!(*dst)[lowest]) {
+			kvm_apic_disabled_lapic_found(kvm);
+			*bitmap = 0;
+			return true;
+		}
+	}
+
+	*bitmap = (lowest >= 0) ? 1 << lowest : 0;
+
+	return true;
+}
+
+bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
+		struct kvm_lapic_irq *irq, int *r, struct dest_map *dest_map)
+{
+	struct kvm_apic_map *map;
+	unsigned long bitmap;
+	struct kvm_lapic **dst = NULL;
+	int i;
+	bool ret;
+
+	*r = -1;
+
+	if (irq->shorthand == APIC_DEST_SELF) {
+		if (KVM_BUG_ON(!src, kvm)) {
+			*r = 0;
+			return true;
+		}
+		*r = kvm_apic_set_irq(src->vcpu, irq, dest_map);
+		return true;
+	}
+
+	rcu_read_lock();
+	map = rcu_dereference(kvm->arch.apic_map);
+
+	ret = kvm_apic_map_get_dest_lapic(kvm, &src, irq, map, &dst, &bitmap);
+	if (ret) {
+		*r = 0;
+		for_each_set_bit(i, &bitmap, 16) {
+			if (!dst[i])
+				continue;
+			*r += kvm_apic_set_irq(dst[i]->vcpu, irq, dest_map);
+		}
+	}
+
+	rcu_read_unlock();
+	return ret;
+}
+
+/*
+ * This routine tries to handle interrupts in posted mode, here is how
+ * it deals with different cases:
+ * - For single-destination interrupts, handle it in posted mode
+ * - Else if vector hashing is enabled and it is a lowest-priority
+ *   interrupt, handle it in posted mode and use the following mechanism
+ *   to find the destination vCPU.
+ *	1. For lowest-priority interrupts, store all the possible
+ *	   destination vCPUs in an array.
+ *	2. Use "guest vector % max number of destination vCPUs" to find
+ *	   the right destination vCPU in the array for the lowest-priority
+ *	   interrupt.
+ * - Otherwise, use remapped mode to inject the interrupt.
+ */
+bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq,
+			struct kvm_vcpu **dest_vcpu)
+{
+	struct kvm_apic_map *map;
+	unsigned long bitmap;
+	struct kvm_lapic **dst = NULL;
+	bool ret = false;
+
+	if (irq->shorthand)
+		return false;
+
+	rcu_read_lock();
+	map = rcu_dereference(kvm->arch.apic_map);
+
+	if (kvm_apic_map_get_dest_lapic(kvm, NULL, irq, map, &dst, &bitmap) &&
+			hweight16(bitmap) == 1) {
+		unsigned long i = find_first_bit(&bitmap, 16);
+
+		if (dst[i]) {
+			*dest_vcpu = dst[i]->vcpu;
+			ret = true;
+		}
+	}
+
+	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,
+			     struct dest_map *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++;
+		fallthrough;
+	case APIC_DM_FIXED:
+		if (unlikely(trig_mode && !level))
+			break;
+
+		/* 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->map);
+			dest_map->vectors[vcpu->vcpu_id] = vector;
+		}
+
+		if (apic_test_vector(vector, apic->regs + APIC_TMR) != !!trig_mode) {
+			if (trig_mode)
+				kvm_lapic_set_vector(vector,
+						     apic->regs + APIC_TMR);
+			else
+				kvm_lapic_clear_vector(vector,
+						       apic->regs + APIC_TMR);
+		}
+
+		static_call(kvm_x86_deliver_interrupt)(apic, delivery_mode,
+						       trig_mode, vector);
+		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:
+		if (!kvm_inject_smi(vcpu)) {
+			kvm_vcpu_kick(vcpu);
+			result = 1;
+		}
+		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);
+			kvm_make_request(KVM_REQ_EVENT, vcpu);
+			kvm_vcpu_kick(vcpu);
+		}
+		break;
+
+	case APIC_DM_STARTUP:
+		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;
+}
+
+/*
+ * This routine identifies the destination vcpus mask meant to receive the
+ * IOAPIC interrupts. It either uses kvm_apic_map_get_dest_lapic() to find
+ * out the destination vcpus array and set the bitmap or it traverses to
+ * each available vcpu to identify the same.
+ */
+void kvm_bitmap_or_dest_vcpus(struct kvm *kvm, struct kvm_lapic_irq *irq,
+			      unsigned long *vcpu_bitmap)
+{
+	struct kvm_lapic **dest_vcpu = NULL;
+	struct kvm_lapic *src = NULL;
+	struct kvm_apic_map *map;
+	struct kvm_vcpu *vcpu;
+	unsigned long bitmap, i;
+	int vcpu_idx;
+	bool ret;
+
+	rcu_read_lock();
+	map = rcu_dereference(kvm->arch.apic_map);
+
+	ret = kvm_apic_map_get_dest_lapic(kvm, &src, irq, map, &dest_vcpu,
+					  &bitmap);
+	if (ret) {
+		for_each_set_bit(i, &bitmap, 16) {
+			if (!dest_vcpu[i])
+				continue;
+			vcpu_idx = dest_vcpu[i]->vcpu->vcpu_idx;
+			__set_bit(vcpu_idx, vcpu_bitmap);
+		}
+	} else {
+		kvm_for_each_vcpu(i, vcpu, kvm) {
+			if (!kvm_apic_present(vcpu))
+				continue;
+			if (!kvm_apic_match_dest(vcpu, NULL,
+						 irq->shorthand,
+						 irq->dest_id,
+						 irq->dest_mode))
+				continue;
+			__set_bit(i, vcpu_bitmap);
+		}
+	}
+	rcu_read_unlock();
+}
+
+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 bool kvm_ioapic_handles_vector(struct kvm_lapic *apic, int vector)
+{
+	return test_bit(vector, apic->vcpu->arch.ioapic_handled_vectors);
+}
+
+static void kvm_ioapic_send_eoi(struct kvm_lapic *apic, int vector)
+{
+	int trigger_mode;
+
+	/* Eoi the ioapic only if the ioapic doesn't own the vector. */
+	if (!kvm_ioapic_handles_vector(apic, vector))
+		return;
+
+	/* Request a KVM exit to inform the userspace IOAPIC. */
+	if (irqchip_split(apic->vcpu->kvm)) {
+		apic->vcpu->arch.pending_ioapic_eoi = vector;
+		kvm_make_request(KVM_REQ_IOAPIC_EOI_EXIT, apic->vcpu);
+		return;
+	}
+
+	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);
+
+	if (to_hv_vcpu(apic->vcpu) &&
+	    test_bit(vector, to_hv_synic(apic->vcpu)->vec_bitmap))
+		kvm_hv_synic_send_eoi(apic->vcpu, vector);
+
+	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);
+
+void kvm_apic_send_ipi(struct kvm_lapic *apic, u32 icr_low, u32 icr_high)
+{
+	struct kvm_lapic_irq irq;
+
+	/* KVM has no delay and should always clear the BUSY/PENDING flag. */
+	WARN_ON_ONCE(icr_low & APIC_ICR_BUSY);
+
+	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) != 0;
+	irq.trig_mode = icr_low & APIC_INT_LEVELTRIG;
+	irq.shorthand = icr_low & APIC_SHORT_MASK;
+	irq.msi_redir_hint = false;
+	if (apic_x2apic_mode(apic))
+		irq.dest_id = icr_high;
+	else
+		irq.dest_id = GET_XAPIC_DEST_FIELD(icr_high);
+
+	trace_kvm_apic_ipi(icr_low, irq.dest_id);
+
+	kvm_irq_delivery_to_apic(apic->vcpu->kvm, apic, &irq, NULL);
+}
+EXPORT_SYMBOL_GPL(kvm_apic_send_ipi);
+
+static u32 apic_get_tmcct(struct kvm_lapic *apic)
+{
+	ktime_t remaining, now;
+	s64 ns;
+
+	ASSERT(apic != NULL);
+
+	/* if initial count is 0, current count should also be 0 */
+	if (kvm_lapic_get_reg(apic, APIC_TMICT) == 0 ||
+		apic->lapic_timer.period == 0)
+		return 0;
+
+	now = ktime_get();
+	remaining = ktime_sub(apic->lapic_timer.target_expiration, now);
+	if (ktime_to_ns(remaining) < 0)
+		remaining = 0;
+
+	ns = mod_64(ktime_to_ns(remaining), apic->lapic_timer.period);
+	return div64_u64(ns, (APIC_BUS_CYCLE_NS * apic->divide_count));
+}
+
+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_ARBPRI:
+		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_lapic_get_reg(apic, offset);
+		break;
+	case APIC_TASKPRI:
+		report_tpr_access(apic, false);
+		fallthrough;
+	default:
+		val = kvm_lapic_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);
+}
+
+#define APIC_REG_MASK(reg)	(1ull << ((reg) >> 4))
+#define APIC_REGS_MASK(first, count) \
+	(APIC_REG_MASK(first) * ((1ull << (count)) - 1))
+
+u64 kvm_lapic_readable_reg_mask(struct kvm_lapic *apic)
+{
+	/* Leave bits '0' for reserved and write-only registers. */
+	u64 valid_reg_mask =
+		APIC_REG_MASK(APIC_ID) |
+		APIC_REG_MASK(APIC_LVR) |
+		APIC_REG_MASK(APIC_TASKPRI) |
+		APIC_REG_MASK(APIC_PROCPRI) |
+		APIC_REG_MASK(APIC_LDR) |
+		APIC_REG_MASK(APIC_SPIV) |
+		APIC_REGS_MASK(APIC_ISR, APIC_ISR_NR) |
+		APIC_REGS_MASK(APIC_TMR, APIC_ISR_NR) |
+		APIC_REGS_MASK(APIC_IRR, APIC_ISR_NR) |
+		APIC_REG_MASK(APIC_ESR) |
+		APIC_REG_MASK(APIC_ICR) |
+		APIC_REG_MASK(APIC_LVTT) |
+		APIC_REG_MASK(APIC_LVTTHMR) |
+		APIC_REG_MASK(APIC_LVTPC) |
+		APIC_REG_MASK(APIC_LVT0) |
+		APIC_REG_MASK(APIC_LVT1) |
+		APIC_REG_MASK(APIC_LVTERR) |
+		APIC_REG_MASK(APIC_TMICT) |
+		APIC_REG_MASK(APIC_TMCCT) |
+		APIC_REG_MASK(APIC_TDCR);
+
+	if (kvm_lapic_lvt_supported(apic, LVT_CMCI))
+		valid_reg_mask |= APIC_REG_MASK(APIC_LVTCMCI);
+
+	/* ARBPRI, DFR, and ICR2 are not valid in x2APIC mode. */
+	if (!apic_x2apic_mode(apic))
+		valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI) |
+				  APIC_REG_MASK(APIC_DFR) |
+				  APIC_REG_MASK(APIC_ICR2);
+
+	return valid_reg_mask;
+}
+EXPORT_SYMBOL_GPL(kvm_lapic_readable_reg_mask);
+
+static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
+			      void *data)
+{
+	unsigned char alignment = offset & 0xf;
+	u32 result;
+
+	/*
+	 * WARN if KVM reads ICR in x2APIC mode, as it's an 8-byte register in
+	 * x2APIC and needs to be manually handled by the caller.
+	 */
+	WARN_ON_ONCE(apic_x2apic_mode(apic) && offset == APIC_ICR);
+
+	if (alignment + len > 4)
+		return 1;
+
+	if (offset > 0x3f0 ||
+	    !(kvm_lapic_readable_reg_mask(apic) & APIC_REG_MASK(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 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;
+
+	if (!kvm_apic_hw_enabled(apic) || apic_x2apic_mode(apic)) {
+		if (!kvm_check_has_quirk(vcpu->kvm,
+					 KVM_X86_QUIRK_LAPIC_MMIO_HOLE))
+			return -EOPNOTSUPP;
+
+		memset(data, 0xff, len);
+		return 0;
+	}
+
+	kvm_lapic_reg_read(apic, offset, len, data);
+
+	return 0;
+}
+
+static void update_divide_count(struct kvm_lapic *apic)
+{
+	u32 tmp1, tmp2, tdcr;
+
+	tdcr = kvm_lapic_get_reg(apic, APIC_TDCR);
+	tmp1 = tdcr & 0xf;
+	tmp2 = ((tmp1 & 0x3) | ((tmp1 & 0x8) >> 1)) + 1;
+	apic->divide_count = 0x1 << (tmp2 & 0x7);
+}
+
+static void limit_periodic_timer_frequency(struct kvm_lapic *apic)
+{
+	/*
+	 * 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) && apic->lapic_timer.period) {
+		s64 min_period = min_timer_period_us * 1000LL;
+
+		if (apic->lapic_timer.period < min_period) {
+			pr_info_ratelimited(
+			    "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;
+		}
+	}
+}
+
+static void cancel_hv_timer(struct kvm_lapic *apic);
+
+static void cancel_apic_timer(struct kvm_lapic *apic)
+{
+	hrtimer_cancel(&apic->lapic_timer.timer);
+	preempt_disable();
+	if (apic->lapic_timer.hv_timer_in_use)
+		cancel_hv_timer(apic);
+	preempt_enable();
+	atomic_set(&apic->lapic_timer.pending, 0);
+}
+
+static void apic_update_lvtt(struct kvm_lapic *apic)
+{
+	u32 timer_mode = kvm_lapic_get_reg(apic, APIC_LVTT) &
+			apic->lapic_timer.timer_mode_mask;
+
+	if (apic->lapic_timer.timer_mode != timer_mode) {
+		if (apic_lvtt_tscdeadline(apic) != (timer_mode ==
+				APIC_LVT_TIMER_TSCDEADLINE)) {
+			cancel_apic_timer(apic);
+			kvm_lapic_set_reg(apic, APIC_TMICT, 0);
+			apic->lapic_timer.period = 0;
+			apic->lapic_timer.tscdeadline = 0;
+		}
+		apic->lapic_timer.timer_mode = timer_mode;
+		limit_periodic_timer_frequency(apic);
+	}
+}
+
+/*
+ * 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_lapic_get_reg(apic, APIC_LVTT);
+
+	if (kvm_apic_hw_enabled(apic)) {
+		int vec = reg & APIC_VECTOR_MASK;
+		void *bitmap = apic->regs + APIC_ISR;
+
+		if (apic->apicv_active)
+			bitmap = apic->regs + APIC_IRR;
+
+		if (apic_test_vector(vec, bitmap))
+			return true;
+	}
+	return false;
+}
+
+static inline void __wait_lapic_expire(struct kvm_vcpu *vcpu, u64 guest_cycles)
+{
+	u64 timer_advance_ns = vcpu->arch.apic->lapic_timer.timer_advance_ns;
+
+	/*
+	 * If the guest TSC is running at a different ratio than the host, then
+	 * convert the delay to nanoseconds to achieve an accurate delay.  Note
+	 * that __delay() uses delay_tsc whenever the hardware has TSC, thus
+	 * always for VMX enabled hardware.
+	 */
+	if (vcpu->arch.tsc_scaling_ratio == kvm_caps.default_tsc_scaling_ratio) {
+		__delay(min(guest_cycles,
+			nsec_to_cycles(vcpu, timer_advance_ns)));
+	} else {
+		u64 delay_ns = guest_cycles * 1000000ULL;
+		do_div(delay_ns, vcpu->arch.virtual_tsc_khz);
+		ndelay(min_t(u32, delay_ns, timer_advance_ns));
+	}
+}
+
+static inline void adjust_lapic_timer_advance(struct kvm_vcpu *vcpu,
+					      s64 advance_expire_delta)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u32 timer_advance_ns = apic->lapic_timer.timer_advance_ns;
+	u64 ns;
+
+	/* Do not adjust for tiny fluctuations or large random spikes. */
+	if (abs(advance_expire_delta) > LAPIC_TIMER_ADVANCE_ADJUST_MAX ||
+	    abs(advance_expire_delta) < LAPIC_TIMER_ADVANCE_ADJUST_MIN)
+		return;
+
+	/* too early */
+	if (advance_expire_delta < 0) {
+		ns = -advance_expire_delta * 1000000ULL;
+		do_div(ns, vcpu->arch.virtual_tsc_khz);
+		timer_advance_ns -= ns/LAPIC_TIMER_ADVANCE_ADJUST_STEP;
+	} else {
+	/* too late */
+		ns = advance_expire_delta * 1000000ULL;
+		do_div(ns, vcpu->arch.virtual_tsc_khz);
+		timer_advance_ns += ns/LAPIC_TIMER_ADVANCE_ADJUST_STEP;
+	}
+
+	if (unlikely(timer_advance_ns > LAPIC_TIMER_ADVANCE_NS_MAX))
+		timer_advance_ns = LAPIC_TIMER_ADVANCE_NS_INIT;
+	apic->lapic_timer.timer_advance_ns = timer_advance_ns;
+}
+
+static void __kvm_wait_lapic_expire(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u64 guest_tsc, tsc_deadline;
+
+	tsc_deadline = apic->lapic_timer.expired_tscdeadline;
+	apic->lapic_timer.expired_tscdeadline = 0;
+	guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc());
+	trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline);
+
+	if (lapic_timer_advance_dynamic) {
+		adjust_lapic_timer_advance(vcpu, guest_tsc - tsc_deadline);
+		/*
+		 * If the timer fired early, reread the TSC to account for the
+		 * overhead of the above adjustment to avoid waiting longer
+		 * than is necessary.
+		 */
+		if (guest_tsc < tsc_deadline)
+			guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc());
+	}
+
+	if (guest_tsc < tsc_deadline)
+		__wait_lapic_expire(vcpu, tsc_deadline - guest_tsc);
+}
+
+void kvm_wait_lapic_expire(struct kvm_vcpu *vcpu)
+{
+	if (lapic_in_kernel(vcpu) &&
+	    vcpu->arch.apic->lapic_timer.expired_tscdeadline &&
+	    vcpu->arch.apic->lapic_timer.timer_advance_ns &&
+	    lapic_timer_int_injected(vcpu))
+		__kvm_wait_lapic_expire(vcpu);
+}
+EXPORT_SYMBOL_GPL(kvm_wait_lapic_expire);
+
+static void kvm_apic_inject_pending_timer_irqs(struct kvm_lapic *apic)
+{
+	struct kvm_timer *ktimer = &apic->lapic_timer;
+
+	kvm_apic_local_deliver(apic, APIC_LVTT);
+	if (apic_lvtt_tscdeadline(apic)) {
+		ktimer->tscdeadline = 0;
+	} else if (apic_lvtt_oneshot(apic)) {
+		ktimer->tscdeadline = 0;
+		ktimer->target_expiration = 0;
+	}
+}
+
+static void apic_timer_expired(struct kvm_lapic *apic, bool from_timer_fn)
+{
+	struct kvm_vcpu *vcpu = apic->vcpu;
+	struct kvm_timer *ktimer = &apic->lapic_timer;
+
+	if (atomic_read(&apic->lapic_timer.pending))
+		return;
+
+	if (apic_lvtt_tscdeadline(apic) || ktimer->hv_timer_in_use)
+		ktimer->expired_tscdeadline = ktimer->tscdeadline;
+
+	if (!from_timer_fn && apic->apicv_active) {
+		WARN_ON(kvm_get_running_vcpu() != vcpu);
+		kvm_apic_inject_pending_timer_irqs(apic);
+		return;
+	}
+
+	if (kvm_use_posted_timer_interrupt(apic->vcpu)) {
+		/*
+		 * Ensure the guest's timer has truly expired before posting an
+		 * interrupt.  Open code the relevant checks to avoid querying
+		 * lapic_timer_int_injected(), which will be false since the
+		 * interrupt isn't yet injected.  Waiting until after injecting
+		 * is not an option since that won't help a posted interrupt.
+		 */
+		if (vcpu->arch.apic->lapic_timer.expired_tscdeadline &&
+		    vcpu->arch.apic->lapic_timer.timer_advance_ns)
+			__kvm_wait_lapic_expire(vcpu);
+		kvm_apic_inject_pending_timer_irqs(apic);
+		return;
+	}
+
+	atomic_inc(&apic->lapic_timer.pending);
+	kvm_make_request(KVM_REQ_UNBLOCK, vcpu);
+	if (from_timer_fn)
+		kvm_vcpu_kick(vcpu);
+}
+
+static void start_sw_tscdeadline(struct kvm_lapic *apic)
+{
+	struct kvm_timer *ktimer = &apic->lapic_timer;
+	u64 guest_tsc, tscdeadline = ktimer->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;
+	ktime_t now;
+
+	if (unlikely(!tscdeadline || !this_tsc_khz))
+		return;
+
+	local_irq_save(flags);
+
+	now = ktime_get();
+	guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc());
+
+	ns = (tscdeadline - guest_tsc) * 1000000ULL;
+	do_div(ns, this_tsc_khz);
+
+	if (likely(tscdeadline > guest_tsc) &&
+	    likely(ns > apic->lapic_timer.timer_advance_ns)) {
+		expire = ktime_add_ns(now, ns);
+		expire = ktime_sub_ns(expire, ktimer->timer_advance_ns);
+		hrtimer_start(&ktimer->timer, expire, HRTIMER_MODE_ABS_HARD);
+	} else
+		apic_timer_expired(apic, false);
+
+	local_irq_restore(flags);
+}
+
+static inline u64 tmict_to_ns(struct kvm_lapic *apic, u32 tmict)
+{
+	return (u64)tmict * APIC_BUS_CYCLE_NS * (u64)apic->divide_count;
+}
+
+static void update_target_expiration(struct kvm_lapic *apic, uint32_t old_divisor)
+{
+	ktime_t now, remaining;
+	u64 ns_remaining_old, ns_remaining_new;
+
+	apic->lapic_timer.period =
+			tmict_to_ns(apic, kvm_lapic_get_reg(apic, APIC_TMICT));
+	limit_periodic_timer_frequency(apic);
+
+	now = ktime_get();
+	remaining = ktime_sub(apic->lapic_timer.target_expiration, now);
+	if (ktime_to_ns(remaining) < 0)
+		remaining = 0;
+
+	ns_remaining_old = ktime_to_ns(remaining);
+	ns_remaining_new = mul_u64_u32_div(ns_remaining_old,
+	                                   apic->divide_count, old_divisor);
+
+	apic->lapic_timer.tscdeadline +=
+		nsec_to_cycles(apic->vcpu, ns_remaining_new) -
+		nsec_to_cycles(apic->vcpu, ns_remaining_old);
+	apic->lapic_timer.target_expiration = ktime_add_ns(now, ns_remaining_new);
+}
+
+static bool set_target_expiration(struct kvm_lapic *apic, u32 count_reg)
+{
+	ktime_t now;
+	u64 tscl = rdtsc();
+	s64 deadline;
+
+	now = ktime_get();
+	apic->lapic_timer.period =
+			tmict_to_ns(apic, kvm_lapic_get_reg(apic, APIC_TMICT));
+
+	if (!apic->lapic_timer.period) {
+		apic->lapic_timer.tscdeadline = 0;
+		return false;
+	}
+
+	limit_periodic_timer_frequency(apic);
+	deadline = apic->lapic_timer.period;
+
+	if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) {
+		if (unlikely(count_reg != APIC_TMICT)) {
+			deadline = tmict_to_ns(apic,
+				     kvm_lapic_get_reg(apic, count_reg));
+			if (unlikely(deadline <= 0)) {
+				if (apic_lvtt_period(apic))
+					deadline = apic->lapic_timer.period;
+				else
+					deadline = 0;
+			}
+			else if (unlikely(deadline > apic->lapic_timer.period)) {
+				pr_info_ratelimited(
+				    "vcpu %i: requested lapic timer restore with "
+				    "starting count register %#x=%u (%lld ns) > initial count (%lld ns). "
+				    "Using initial count to start timer.\n",
+				    apic->vcpu->vcpu_id,
+				    count_reg,
+				    kvm_lapic_get_reg(apic, count_reg),
+				    deadline, apic->lapic_timer.period);
+				kvm_lapic_set_reg(apic, count_reg, 0);
+				deadline = apic->lapic_timer.period;
+			}
+		}
+	}
+
+	apic->lapic_timer.tscdeadline = kvm_read_l1_tsc(apic->vcpu, tscl) +
+		nsec_to_cycles(apic->vcpu, deadline);
+	apic->lapic_timer.target_expiration = ktime_add_ns(now, deadline);
+
+	return true;
+}
+
+static void advance_periodic_target_expiration(struct kvm_lapic *apic)
+{
+	ktime_t now = ktime_get();
+	u64 tscl = rdtsc();
+	ktime_t delta;
+
+	/*
+	 * Synchronize both deadlines to the same time source or
+	 * differences in the periods (caused by differences in the
+	 * underlying clocks or numerical approximation errors) will
+	 * cause the two to drift apart over time as the errors
+	 * accumulate.
+	 */
+	apic->lapic_timer.target_expiration =
+		ktime_add_ns(apic->lapic_timer.target_expiration,
+				apic->lapic_timer.period);
+	delta = ktime_sub(apic->lapic_timer.target_expiration, now);
+	apic->lapic_timer.tscdeadline = kvm_read_l1_tsc(apic->vcpu, tscl) +
+		nsec_to_cycles(apic->vcpu, delta);
+}
+
+static void start_sw_period(struct kvm_lapic *apic)
+{
+	if (!apic->lapic_timer.period)
+		return;
+
+	if (ktime_after(ktime_get(),
+			apic->lapic_timer.target_expiration)) {
+		apic_timer_expired(apic, false);
+
+		if (apic_lvtt_oneshot(apic))
+			return;
+
+		advance_periodic_target_expiration(apic);
+	}
+
+	hrtimer_start(&apic->lapic_timer.timer,
+		apic->lapic_timer.target_expiration,
+		HRTIMER_MODE_ABS_HARD);
+}
+
+bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu)
+{
+	if (!lapic_in_kernel(vcpu))
+		return false;
+
+	return vcpu->arch.apic->lapic_timer.hv_timer_in_use;
+}
+
+static void cancel_hv_timer(struct kvm_lapic *apic)
+{
+	WARN_ON(preemptible());
+	WARN_ON(!apic->lapic_timer.hv_timer_in_use);
+	static_call(kvm_x86_cancel_hv_timer)(apic->vcpu);
+	apic->lapic_timer.hv_timer_in_use = false;
+}
+
+static bool start_hv_timer(struct kvm_lapic *apic)
+{
+	struct kvm_timer *ktimer = &apic->lapic_timer;
+	struct kvm_vcpu *vcpu = apic->vcpu;
+	bool expired;
+
+	WARN_ON(preemptible());
+	if (!kvm_can_use_hv_timer(vcpu))
+		return false;
+
+	if (!ktimer->tscdeadline)
+		return false;
+
+	if (static_call(kvm_x86_set_hv_timer)(vcpu, ktimer->tscdeadline, &expired))
+		return false;
+
+	ktimer->hv_timer_in_use = true;
+	hrtimer_cancel(&ktimer->timer);
+
+	/*
+	 * To simplify handling the periodic timer, leave the hv timer running
+	 * even if the deadline timer has expired, i.e. rely on the resulting
+	 * VM-Exit to recompute the periodic timer's target expiration.
+	 */
+	if (!apic_lvtt_period(apic)) {
+		/*
+		 * Cancel the hv timer if the sw timer fired while the hv timer
+		 * was being programmed, or if the hv timer itself expired.
+		 */
+		if (atomic_read(&ktimer->pending)) {
+			cancel_hv_timer(apic);
+		} else if (expired) {
+			apic_timer_expired(apic, false);
+			cancel_hv_timer(apic);
+		}
+	}
+
+	trace_kvm_hv_timer_state(vcpu->vcpu_id, ktimer->hv_timer_in_use);
+
+	return true;
+}
+
+static void start_sw_timer(struct kvm_lapic *apic)
+{
+	struct kvm_timer *ktimer = &apic->lapic_timer;
+
+	WARN_ON(preemptible());
+	if (apic->lapic_timer.hv_timer_in_use)
+		cancel_hv_timer(apic);
+	if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
+		return;
+
+	if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic))
+		start_sw_period(apic);
+	else if (apic_lvtt_tscdeadline(apic))
+		start_sw_tscdeadline(apic);
+	trace_kvm_hv_timer_state(apic->vcpu->vcpu_id, false);
+}
+
+static void restart_apic_timer(struct kvm_lapic *apic)
+{
+	preempt_disable();
+
+	if (!apic_lvtt_period(apic) && atomic_read(&apic->lapic_timer.pending))
+		goto out;
+
+	if (!start_hv_timer(apic))
+		start_sw_timer(apic);
+out:
+	preempt_enable();
+}
+
+void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	preempt_disable();
+	/* If the preempt notifier has already run, it also called apic_timer_expired */
+	if (!apic->lapic_timer.hv_timer_in_use)
+		goto out;
+	WARN_ON(kvm_vcpu_is_blocking(vcpu));
+	apic_timer_expired(apic, false);
+	cancel_hv_timer(apic);
+
+	if (apic_lvtt_period(apic) && apic->lapic_timer.period) {
+		advance_periodic_target_expiration(apic);
+		restart_apic_timer(apic);
+	}
+out:
+	preempt_enable();
+}
+EXPORT_SYMBOL_GPL(kvm_lapic_expired_hv_timer);
+
+void kvm_lapic_switch_to_hv_timer(struct kvm_vcpu *vcpu)
+{
+	restart_apic_timer(vcpu->arch.apic);
+}
+
+void kvm_lapic_switch_to_sw_timer(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	preempt_disable();
+	/* Possibly the TSC deadline timer is not enabled yet */
+	if (apic->lapic_timer.hv_timer_in_use)
+		start_sw_timer(apic);
+	preempt_enable();
+}
+
+void kvm_lapic_restart_hv_timer(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	WARN_ON(!apic->lapic_timer.hv_timer_in_use);
+	restart_apic_timer(apic);
+}
+
+static void __start_apic_timer(struct kvm_lapic *apic, u32 count_reg)
+{
+	atomic_set(&apic->lapic_timer.pending, 0);
+
+	if ((apic_lvtt_period(apic) || apic_lvtt_oneshot(apic))
+	    && !set_target_expiration(apic, count_reg))
+		return;
+
+	restart_apic_timer(apic);
+}
+
+static void start_apic_timer(struct kvm_lapic *apic)
+{
+	__start_apic_timer(apic, APIC_TMICT);
+}
+
+static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
+{
+	bool lvt0_in_nmi_mode = apic_lvt_nmi_mode(lvt0_val);
+
+	if (apic->lvt0_in_nmi_mode != lvt0_in_nmi_mode) {
+		apic->lvt0_in_nmi_mode = lvt0_in_nmi_mode;
+		if (lvt0_in_nmi_mode) {
+			atomic_inc(&apic->vcpu->kvm->arch.vapics_in_nmi_mode);
+		} else
+			atomic_dec(&apic->vcpu->kvm->arch.vapics_in_nmi_mode);
+	}
+}
+
+static int get_lvt_index(u32 reg)
+{
+	if (reg == APIC_LVTCMCI)
+		return LVT_CMCI;
+	if (reg < APIC_LVTT || reg > APIC_LVTERR)
+		return -1;
+	return array_index_nospec(
+			(reg - APIC_LVTT) >> 4, KVM_APIC_MAX_NR_LVT_ENTRIES);
+}
+
+static int kvm_lapic_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_xapic_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))
+			kvm_apic_set_dfr(apic, val | 0x0FFFFFFF);
+		else
+			ret = 1;
+		break;
+
+	case APIC_SPIV: {
+		u32 mask = 0x3ff;
+		if (kvm_lapic_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;
+
+			for (i = 0; i < apic->nr_lvt_entries; i++) {
+				kvm_lapic_set_reg(apic, APIC_LVTx(i),
+					kvm_lapic_get_reg(apic, APIC_LVTx(i)) | APIC_LVT_MASKED);
+			}
+			apic_update_lvtt(apic);
+			atomic_set(&apic->lapic_timer.pending, 0);
+
+		}
+		break;
+	}
+	case APIC_ICR:
+		WARN_ON_ONCE(apic_x2apic_mode(apic));
+
+		/* No delay here, so we always clear the pending bit */
+		val &= ~APIC_ICR_BUSY;
+		kvm_apic_send_ipi(apic, val, kvm_lapic_get_reg(apic, APIC_ICR2));
+		kvm_lapic_set_reg(apic, APIC_ICR, val);
+		break;
+	case APIC_ICR2:
+		if (apic_x2apic_mode(apic))
+			ret = 1;
+		else
+			kvm_lapic_set_reg(apic, APIC_ICR2, val & 0xff000000);
+		break;
+
+	case APIC_LVT0:
+		apic_manage_nmi_watchdog(apic, val);
+		fallthrough;
+	case APIC_LVTTHMR:
+	case APIC_LVTPC:
+	case APIC_LVT1:
+	case APIC_LVTERR:
+	case APIC_LVTCMCI: {
+		u32 index = get_lvt_index(reg);
+		if (!kvm_lapic_lvt_supported(apic, index)) {
+			ret = 1;
+			break;
+		}
+		if (!kvm_apic_sw_enabled(apic))
+			val |= APIC_LVT_MASKED;
+		val &= apic_lvt_mask[index];
+		kvm_lapic_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);
+		kvm_lapic_set_reg(apic, APIC_LVTT, val);
+		apic_update_lvtt(apic);
+		break;
+
+	case APIC_TMICT:
+		if (apic_lvtt_tscdeadline(apic))
+			break;
+
+		cancel_apic_timer(apic);
+		kvm_lapic_set_reg(apic, APIC_TMICT, val);
+		start_apic_timer(apic);
+		break;
+
+	case APIC_TDCR: {
+		uint32_t old_divisor = apic->divide_count;
+
+		kvm_lapic_set_reg(apic, APIC_TDCR, val & 0xb);
+		update_divide_count(apic);
+		if (apic->divide_count != old_divisor &&
+				apic->lapic_timer.period) {
+			hrtimer_cancel(&apic->lapic_timer.timer);
+			update_target_expiration(apic, old_divisor);
+			restart_apic_timer(apic);
+		}
+		break;
+	}
+	case APIC_ESR:
+		if (apic_x2apic_mode(apic) && val != 0)
+			ret = 1;
+		break;
+
+	case APIC_SELF_IPI:
+		/*
+		 * Self-IPI exists only when x2APIC is enabled.  Bits 7:0 hold
+		 * the vector, everything else is reserved.
+		 */
+		if (!apic_x2apic_mode(apic) || (val & ~APIC_VECTOR_MASK))
+			ret = 1;
+		else
+			kvm_apic_send_ipi(apic, APIC_DEST_SELF | val, 0);
+		break;
+	default:
+		ret = 1;
+		break;
+	}
+
+	/*
+	 * Recalculate APIC maps if necessary, e.g. if the software enable bit
+	 * was toggled, the APIC ID changed, etc...   The maps are marked dirty
+	 * on relevant changes, i.e. this is a nop for most writes.
+	 */
+	kvm_recalculate_apic_map(apic->vcpu->kvm);
+
+	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;
+
+	if (!kvm_apic_hw_enabled(apic) || apic_x2apic_mode(apic)) {
+		if (!kvm_check_has_quirk(vcpu->kvm,
+					 KVM_X86_QUIRK_LAPIC_MMIO_HOLE))
+			return -EOPNOTSUPP;
+
+		return 0;
+	}
+
+	/*
+	 * 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))
+		return 0;
+
+	val = *(u32*)data;
+
+	kvm_lapic_reg_write(apic, offset & 0xff0, val);
+
+	return 0;
+}
+
+void kvm_lapic_set_eoi(struct kvm_vcpu *vcpu)
+{
+	kvm_lapic_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)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	/*
+	 * ICR is a single 64-bit register when x2APIC is enabled, all others
+	 * registers hold 32-bit values.  For legacy xAPIC, ICR writes need to
+	 * go down the common path to get the upper half from ICR2.
+	 *
+	 * Note, using the write helpers may incur an unnecessary write to the
+	 * virtual APIC state, but KVM needs to conditionally modify the value
+	 * in certain cases, e.g. to clear the ICR busy bit.  The cost of extra
+	 * conditional branches is likely a wash relative to the cost of the
+	 * maybe-unecessary write, and both are in the noise anyways.
+	 */
+	if (apic_x2apic_mode(apic) && offset == APIC_ICR)
+		kvm_x2apic_icr_write(apic, kvm_lapic_get_reg64(apic, APIC_ICR));
+	else
+		kvm_lapic_reg_write(apic, offset, kvm_lapic_get_reg(apic, offset));
+}
+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_branch_slow_dec_deferred(&apic_hw_disabled);
+
+	if (!apic->sw_enabled)
+		static_branch_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_apic_present(vcpu) || !apic_lvtt_tscdeadline(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_apic_present(vcpu) || !apic_lvtt_tscdeadline(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)
+{
+	apic_set_tpr(vcpu->arch.apic, (cr8 & 0x0f) << 4);
+}
+
+u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)
+{
+	u64 tpr;
+
+	tpr = (u64) kvm_lapic_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;
+
+	vcpu->arch.apic_base = value;
+
+	if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE)
+		kvm_update_cpuid_runtime(vcpu);
+
+	if (!apic)
+		return;
+
+	/* update jump label if enable bit changes */
+	if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) {
+		if (value & MSR_IA32_APICBASE_ENABLE) {
+			kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
+			static_branch_slow_dec_deferred(&apic_hw_disabled);
+			/* Check if there are APF page ready requests pending */
+			kvm_make_request(KVM_REQ_APF_READY, vcpu);
+		} else {
+			static_branch_inc(&apic_hw_disabled.key);
+			atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
+		}
+	}
+
+	if ((old_value ^ value) & X2APIC_ENABLE) {
+		if (value & X2APIC_ENABLE)
+			kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
+		else if (value & MSR_IA32_APICBASE_ENABLE)
+			kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
+	}
+
+	if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) {
+		kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
+		static_call_cond(kvm_x86_set_virtual_apic_mode)(vcpu);
+	}
+
+	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) {
+		kvm_set_apicv_inhibit(apic->vcpu->kvm,
+				      APICV_INHIBIT_REASON_APIC_BASE_MODIFIED);
+	}
+}
+
+void kvm_apic_update_apicv(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (apic->apicv_active) {
+		/* irr_pending is always true when apicv is activated. */
+		apic->irr_pending = true;
+		apic->isr_count = 1;
+	} else {
+		/*
+		 * Don't clear irr_pending, searching the IRR can race with
+		 * updates from the CPU as APICv is still active from hardware's
+		 * perspective.  The flag will be cleared as appropriate when
+		 * KVM injects the interrupt.
+		 */
+		apic->isr_count = count_vectors(apic->regs + APIC_ISR);
+	}
+	apic->highest_isr_cache = -1;
+}
+
+int kvm_alloc_apic_access_page(struct kvm *kvm)
+{
+	struct page *page;
+	void __user *hva;
+	int ret = 0;
+
+	mutex_lock(&kvm->slots_lock);
+	if (kvm->arch.apic_access_memslot_enabled ||
+	    kvm->arch.apic_access_memslot_inhibited)
+		goto out;
+
+	hva = __x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT,
+				      APIC_DEFAULT_PHYS_BASE, PAGE_SIZE);
+	if (IS_ERR(hva)) {
+		ret = PTR_ERR(hva);
+		goto out;
+	}
+
+	page = gfn_to_page(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
+	if (is_error_page(page)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	/*
+	 * Do not pin the page in memory, so that memory hot-unplug
+	 * is able to migrate it.
+	 */
+	put_page(page);
+	kvm->arch.apic_access_memslot_enabled = true;
+out:
+	mutex_unlock(&kvm->slots_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_alloc_apic_access_page);
+
+void kvm_inhibit_apic_access_page(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+
+	if (!kvm->arch.apic_access_memslot_enabled)
+		return;
+
+	kvm_vcpu_srcu_read_unlock(vcpu);
+
+	mutex_lock(&kvm->slots_lock);
+
+	if (kvm->arch.apic_access_memslot_enabled) {
+		__x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, 0, 0);
+		/*
+		 * Clear "enabled" after the memslot is deleted so that a
+		 * different vCPU doesn't get a false negative when checking
+		 * the flag out of slots_lock.  No additional memory barrier is
+		 * needed as modifying memslots requires waiting other vCPUs to
+		 * drop SRCU (see above), and false positives are ok as the
+		 * flag is rechecked after acquiring slots_lock.
+		 */
+		kvm->arch.apic_access_memslot_enabled = false;
+
+		/*
+		 * Mark the memslot as inhibited to prevent reallocating the
+		 * memslot during vCPU creation, e.g. if a vCPU is hotplugged.
+		 */
+		kvm->arch.apic_access_memslot_inhibited = true;
+	}
+
+	mutex_unlock(&kvm->slots_lock);
+
+	kvm_vcpu_srcu_read_lock(vcpu);
+}
+
+void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u64 msr_val;
+	int i;
+
+	static_call_cond(kvm_x86_apicv_pre_state_restore)(vcpu);
+
+	if (!init_event) {
+		msr_val = APIC_DEFAULT_PHYS_BASE | MSR_IA32_APICBASE_ENABLE;
+		if (kvm_vcpu_is_reset_bsp(vcpu))
+			msr_val |= MSR_IA32_APICBASE_BSP;
+		kvm_lapic_set_base(vcpu, msr_val);
+	}
+
+	if (!apic)
+		return;
+
+	/* Stop the timer in case it's a reset to an active apic */
+	hrtimer_cancel(&apic->lapic_timer.timer);
+
+	/* The xAPIC ID is set at RESET even if the APIC was already enabled. */
+	if (!init_event)
+		kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
+	kvm_apic_set_version(apic->vcpu);
+
+	for (i = 0; i < apic->nr_lvt_entries; i++)
+		kvm_lapic_set_reg(apic, APIC_LVTx(i), APIC_LVT_MASKED);
+	apic_update_lvtt(apic);
+	if (kvm_vcpu_is_reset_bsp(vcpu) &&
+	    kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_LINT0_REENABLED))
+		kvm_lapic_set_reg(apic, APIC_LVT0,
+			     SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT));
+	apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0));
+
+	kvm_apic_set_dfr(apic, 0xffffffffU);
+	apic_set_spiv(apic, 0xff);
+	kvm_lapic_set_reg(apic, APIC_TASKPRI, 0);
+	if (!apic_x2apic_mode(apic))
+		kvm_apic_set_ldr(apic, 0);
+	kvm_lapic_set_reg(apic, APIC_ESR, 0);
+	if (!apic_x2apic_mode(apic)) {
+		kvm_lapic_set_reg(apic, APIC_ICR, 0);
+		kvm_lapic_set_reg(apic, APIC_ICR2, 0);
+	} else {
+		kvm_lapic_set_reg64(apic, APIC_ICR, 0);
+	}
+	kvm_lapic_set_reg(apic, APIC_TDCR, 0);
+	kvm_lapic_set_reg(apic, APIC_TMICT, 0);
+	for (i = 0; i < 8; i++) {
+		kvm_lapic_set_reg(apic, APIC_IRR + 0x10 * i, 0);
+		kvm_lapic_set_reg(apic, APIC_ISR + 0x10 * i, 0);
+		kvm_lapic_set_reg(apic, APIC_TMR + 0x10 * i, 0);
+	}
+	kvm_apic_update_apicv(vcpu);
+	update_divide_count(apic);
+	atomic_set(&apic->lapic_timer.pending, 0);
+
+	vcpu->arch.pv_eoi.msr_val = 0;
+	apic_update_ppr(apic);
+	if (apic->apicv_active) {
+		static_call_cond(kvm_x86_apicv_post_state_restore)(vcpu);
+		static_call_cond(kvm_x86_hwapic_irr_update)(vcpu, -1);
+		static_call_cond(kvm_x86_hwapic_isr_update)(-1);
+	}
+
+	vcpu->arch.apic_arb_prio = 0;
+	vcpu->arch.apic_attention = 0;
+
+	kvm_recalculate_apic_map(vcpu->kvm);
+}
+
+/*
+ *----------------------------------------------------------------------
+ * 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 (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_lapic_get_reg(apic, lvt_type);
+	int vector, mode, trig_mode;
+	int r;
+
+	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;
+
+		r = __apic_accept_irq(apic, mode, vector, 1, trig_mode, NULL);
+		if (r && lvt_type == APIC_LVTPC)
+			kvm_lapic_set_reg(apic, APIC_LVTPC, reg | APIC_LVT_MASKED);
+		return r;
+	}
+	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, true);
+
+	if (lapic_is_periodic(apic)) {
+		advance_periodic_target_expiration(apic);
+		hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
+		return HRTIMER_RESTART;
+	} else
+		return HRTIMER_NORESTART;
+}
+
+int kvm_create_lapic(struct kvm_vcpu *vcpu, int timer_advance_ns)
+{
+	struct kvm_lapic *apic;
+
+	ASSERT(vcpu != NULL);
+
+	apic = kzalloc(sizeof(*apic), GFP_KERNEL_ACCOUNT);
+	if (!apic)
+		goto nomem;
+
+	vcpu->arch.apic = apic;
+
+	apic->regs = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+	if (!apic->regs) {
+		printk(KERN_ERR "malloc apic regs error for vcpu %x\n",
+		       vcpu->vcpu_id);
+		goto nomem_free_apic;
+	}
+	apic->vcpu = vcpu;
+
+	apic->nr_lvt_entries = kvm_apic_calc_nr_lvt_entries(vcpu);
+
+	hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_ABS_HARD);
+	apic->lapic_timer.timer.function = apic_timer_fn;
+	if (timer_advance_ns == -1) {
+		apic->lapic_timer.timer_advance_ns = LAPIC_TIMER_ADVANCE_NS_INIT;
+		lapic_timer_advance_dynamic = true;
+	} else {
+		apic->lapic_timer.timer_advance_ns = timer_advance_ns;
+		lapic_timer_advance_dynamic = false;
+	}
+
+	/*
+	 * Stuff the APIC ENABLE bit in lieu of temporarily incrementing
+	 * apic_hw_disabled; the full RESET value is set by kvm_lapic_reset().
+	 */
+	vcpu->arch.apic_base = MSR_IA32_APICBASE_ENABLE;
+	static_branch_inc(&apic_sw_disabled.key); /* sw disabled at reset */
+	kvm_iodevice_init(&apic->dev, &apic_mmio_ops);
+
+	return 0;
+nomem_free_apic:
+	kfree(apic);
+	vcpu->arch.apic = NULL;
+nomem:
+	return -ENOMEM;
+}
+
+int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u32 ppr;
+
+	if (!kvm_apic_present(vcpu))
+		return -1;
+
+	__apic_update_ppr(apic, &ppr);
+	return apic_has_interrupt_for_ppr(apic, ppr);
+}
+EXPORT_SYMBOL_GPL(kvm_apic_has_interrupt);
+
+int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu)
+{
+	u32 lvt0 = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LVT0);
+
+	if (!kvm_apic_hw_enabled(vcpu->arch.apic))
+		return 1;
+	if ((lvt0 & APIC_LVT_MASKED) == 0 &&
+	    GET_APIC_DELIVERY_MODE(lvt0) == APIC_MODE_EXTINT)
+		return 1;
+	return 0;
+}
+
+void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	if (atomic_read(&apic->lapic_timer.pending) > 0) {
+		kvm_apic_inject_pending_timer_irqs(apic);
+		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;
+	u32 ppr;
+
+	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_clear_irr(vector, apic);
+	if (to_hv_vcpu(vcpu) && test_bit(vector, to_hv_synic(vcpu)->auto_eoi_bitmap)) {
+		/*
+		 * For auto-EOI interrupts, there might be another pending
+		 * interrupt above PPR, so check whether to raise another
+		 * KVM_REQ_EVENT.
+		 */
+		apic_update_ppr(apic);
+	} else {
+		/*
+		 * For normal interrupts, PPR has been raised and there cannot
+		 * be a higher-priority pending interrupt---except if there was
+		 * a concurrent interrupt injection, but that would have
+		 * triggered KVM_REQ_EVENT already.
+		 */
+		apic_set_isr(vector, apic);
+		__apic_update_ppr(apic, &ppr);
+	}
+
+	return vector;
+}
+
+static int kvm_apic_state_fixup(struct kvm_vcpu *vcpu,
+		struct kvm_lapic_state *s, bool set)
+{
+	if (apic_x2apic_mode(vcpu->arch.apic)) {
+		u32 *id = (u32 *)(s->regs + APIC_ID);
+		u32 *ldr = (u32 *)(s->regs + APIC_LDR);
+		u64 icr;
+
+		if (vcpu->kvm->arch.x2apic_format) {
+			if (*id != vcpu->vcpu_id)
+				return -EINVAL;
+		} else {
+			if (set)
+				*id >>= 24;
+			else
+				*id <<= 24;
+		}
+
+		/*
+		 * In x2APIC mode, the LDR is fixed and based on the id.  And
+		 * ICR is internally a single 64-bit register, but needs to be
+		 * split to ICR+ICR2 in userspace for backwards compatibility.
+		 */
+		if (set) {
+			*ldr = kvm_apic_calc_x2apic_ldr(*id);
+
+			icr = __kvm_lapic_get_reg(s->regs, APIC_ICR) |
+			      (u64)__kvm_lapic_get_reg(s->regs, APIC_ICR2) << 32;
+			__kvm_lapic_set_reg64(s->regs, APIC_ICR, icr);
+		} else {
+			icr = __kvm_lapic_get_reg64(s->regs, APIC_ICR);
+			__kvm_lapic_set_reg(s->regs, APIC_ICR2, icr >> 32);
+		}
+	}
+
+	return 0;
+}
+
+int kvm_apic_get_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s)
+{
+	memcpy(s->regs, vcpu->arch.apic->regs, sizeof(*s));
+
+	/*
+	 * Get calculated timer current count for remaining timer period (if
+	 * any) and store it in the returned register set.
+	 */
+	__kvm_lapic_set_reg(s->regs, APIC_TMCCT,
+			    __apic_read(vcpu->arch.apic, APIC_TMCCT));
+
+	return kvm_apic_state_fixup(vcpu, s, false);
+}
+
+int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	int r;
+
+	static_call_cond(kvm_x86_apicv_pre_state_restore)(vcpu);
+
+	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)));
+
+	r = kvm_apic_state_fixup(vcpu, s, true);
+	if (r) {
+		kvm_recalculate_apic_map(vcpu->kvm);
+		return r;
+	}
+	memcpy(vcpu->arch.apic->regs, s->regs, sizeof(*s));
+
+	atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY);
+	kvm_recalculate_apic_map(vcpu->kvm);
+	kvm_apic_set_version(vcpu);
+
+	apic_update_ppr(apic);
+	cancel_apic_timer(apic);
+	apic->lapic_timer.expired_tscdeadline = 0;
+	apic_update_lvtt(apic);
+	apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0));
+	update_divide_count(apic);
+	__start_apic_timer(apic, APIC_TMCCT);
+	kvm_lapic_set_reg(apic, APIC_TMCCT, 0);
+	kvm_apic_update_apicv(vcpu);
+	if (apic->apicv_active) {
+		static_call_cond(kvm_x86_apicv_post_state_restore)(vcpu);
+		static_call_cond(kvm_x86_hwapic_irr_update)(vcpu, apic_find_highest_irr(apic));
+		static_call_cond(kvm_x86_hwapic_isr_update)(apic_find_highest_isr(apic));
+	}
+	kvm_make_request(KVM_REQ_EVENT, vcpu);
+	if (ioapic_in_kernel(vcpu->kvm))
+		kvm_rtc_eoi_tracking_restore_one(vcpu);
+
+	vcpu->arch.apic_arb_prio = 0;
+
+	return 0;
+}
+
+void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
+{
+	struct hrtimer *timer;
+
+	if (!lapic_in_kernel(vcpu) ||
+		kvm_can_post_timer_interrupt(vcpu))
+		return;
+
+	timer = &vcpu->arch.apic->lapic_timer.timer;
+	if (hrtimer_cancel(timer))
+		hrtimer_start_expires(timer, HRTIMER_MODE_ABS_HARD);
+}
+
+/*
+ * 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)
+{
+	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));
+
+	if (pv_eoi_test_and_clr_pending(vcpu))
+		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;
+
+	if (kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data,
+				  sizeof(u32)))
+		return;
+
+	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(apic, 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_lapic_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_icr_write(struct kvm_lapic *apic, u64 data)
+{
+	data &= ~APIC_ICR_BUSY;
+
+	kvm_apic_send_ipi(apic, (u32)data, (u32)(data >> 32));
+	kvm_lapic_set_reg64(apic, APIC_ICR, data);
+	trace_kvm_apic_write(APIC_ICR, data);
+	return 0;
+}
+
+static int kvm_lapic_msr_read(struct kvm_lapic *apic, u32 reg, u64 *data)
+{
+	u32 low;
+
+	if (reg == APIC_ICR) {
+		*data = kvm_lapic_get_reg64(apic, APIC_ICR);
+		return 0;
+	}
+
+	if (kvm_lapic_reg_read(apic, reg, 4, &low))
+		return 1;
+
+	*data = low;
+
+	return 0;
+}
+
+static int kvm_lapic_msr_write(struct kvm_lapic *apic, u32 reg, u64 data)
+{
+	/*
+	 * ICR is a 64-bit register in x2APIC mode (and Hyper-V PV vAPIC) and
+	 * can be written as such, all other registers remain accessible only
+	 * through 32-bit reads/writes.
+	 */
+	if (reg == APIC_ICR)
+		return kvm_x2apic_icr_write(apic, data);
+
+	/* Bits 63:32 are reserved in all other registers. */
+	if (data >> 32)
+		return 1;
+
+	return kvm_lapic_reg_write(apic, reg, (u32)data);
+}
+
+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 (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic))
+		return 1;
+
+	return kvm_lapic_msr_write(apic, reg, 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;
+
+	if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic))
+		return 1;
+
+	return kvm_lapic_msr_read(apic, reg, data);
+}
+
+int kvm_hv_vapic_msr_write(struct kvm_vcpu *vcpu, u32 reg, u64 data)
+{
+	if (!lapic_in_kernel(vcpu))
+		return 1;
+
+	return kvm_lapic_msr_write(vcpu->arch.apic, reg, data);
+}
+
+int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data)
+{
+	if (!lapic_in_kernel(vcpu))
+		return 1;
+
+	return kvm_lapic_msr_read(vcpu->arch.apic, reg, data);
+}
+
+int kvm_lapic_set_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len)
+{
+	u64 addr = data & ~KVM_MSR_ENABLED;
+	struct gfn_to_hva_cache *ghc = &vcpu->arch.pv_eoi.data;
+	unsigned long new_len;
+	int ret;
+
+	if (!IS_ALIGNED(addr, 4))
+		return 1;
+
+	if (data & KVM_MSR_ENABLED) {
+		if (addr == ghc->gpa && len <= ghc->len)
+			new_len = ghc->len;
+		else
+			new_len = len;
+
+		ret = kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, addr, new_len);
+		if (ret)
+			return ret;
+	}
+
+	vcpu->arch.pv_eoi.msr_val = data;
+
+	return 0;
+}
+
+int kvm_apic_accept_events(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	u8 sipi_vector;
+	int r;
+
+	if (!kvm_apic_has_pending_init_or_sipi(vcpu))
+		return 0;
+
+	if (is_guest_mode(vcpu)) {
+		r = kvm_check_nested_events(vcpu);
+		if (r < 0)
+			return r == -EBUSY ? 0 : r;
+		/*
+		 * Continue processing INIT/SIPI even if a nested VM-Exit
+		 * occurred, e.g. pending SIPIs should be dropped if INIT+SIPI
+		 * are blocked as a result of transitioning to VMX root mode.
+		 */
+	}
+
+	/*
+	 * INITs are blocked while CPU is in specific states (SMM, VMX root
+	 * mode, SVM with GIF=0), while SIPIs are dropped if the CPU isn't in
+	 * wait-for-SIPI (WFS).
+	 */
+	if (!kvm_apic_init_sipi_allowed(vcpu)) {
+		WARN_ON_ONCE(vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED);
+		clear_bit(KVM_APIC_SIPI, &apic->pending_events);
+		return 0;
+	}
+
+	if (test_and_clear_bit(KVM_APIC_INIT, &apic->pending_events)) {
+		kvm_vcpu_reset(vcpu, true);
+		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_and_clear_bit(KVM_APIC_SIPI, &apic->pending_events)) {
+		if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
+			/* evaluate pending_events before reading the vector */
+			smp_rmb();
+			sipi_vector = apic->sipi_vector;
+			static_call(kvm_x86_vcpu_deliver_sipi_vector)(vcpu, sipi_vector);
+			vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+		}
+	}
+	return 0;
+}
+
+void kvm_lapic_exit(void)
+{
+	static_key_deferred_flush(&apic_hw_disabled);
+	WARN_ON(static_branch_unlikely(&apic_hw_disabled.key));
+	static_key_deferred_flush(&apic_sw_disabled);
+	WARN_ON(static_branch_unlikely(&apic_sw_disabled.key));
+}