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linux/arch/x86/kvm/lapic.c
Wanpeng Li b6c4bc659c KVM: LAPIC: Optimize timer latency further 
Advance lapic timer tries to hidden the hypervisor overhead between the
host emulated timer fires and the guest awares the timer is fired. However,
it just hidden the time between apic_timer_fn/handle_preemption_timer ->
wait_lapic_expire, instead of the real position of vmentry which is
mentioned in the orignial commit d0659d946b ("KVM: x86: add option to
advance tscdeadline hrtimer expiration"). There is 700+ cpu cycles between
the end of wait_lapic_expire and before world switch on my haswell desktop.

This patch tries to narrow the last gap(wait_lapic_expire -> world switch),
it takes the real overhead time between apic_timer_fn/handle_preemption_timer
and before world switch into consideration when adaptively tuning timer
advancement. The patch can reduce 40% latency (~1600+ cycles to ~1000+ cycles
on a haswell desktop) for kvm-unit-tests/tscdeadline_latency when testing
busy waits.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-06-04 19:27:30 +02:00

2781 lines
70 KiB
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/*
* 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/export.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"
#include "hyperv.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_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg) */
#define apic_debug(fmt, arg...) do {} while (0)
/* 14 is the version for Xeon and Pentium 8.4.8*/
#define APIC_VERSION (0x14UL | ((KVM_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 LAPIC_TIMER_ADVANCE_ADJUST_DONE 100
/* step-by-step approximation to mitigate fluctuation */
#define LAPIC_TIMER_ADVANCE_ADJUST_STEP 8
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_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 u8 kvm_xapic_id(struct kvm_lapic *apic)
{
return kvm_lapic_get_reg(apic, APIC_ID) >> 24;
}
static inline u32 kvm_x2apic_id(struct kvm_lapic *apic)
{
return apic->vcpu->vcpu_id;
}
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->mode) {
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;
default:
/* Not optimized. */
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 void recalculate_apic_map(struct kvm *kvm)
{
struct kvm_apic_map *new, *old = NULL;
struct kvm_vcpu *vcpu;
int i;
u32 max_id = 255; /* enough space for any xAPIC ID */
mutex_lock(&kvm->arch.apic_map_lock);
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;
kvm_for_each_vcpu(i, vcpu, kvm) {
struct kvm_lapic *apic = vcpu->arch.apic;
struct kvm_lapic **cluster;
u16 mask;
u32 ldr;
u8 xapic_id;
u32 x2apic_id;
if (!kvm_apic_present(vcpu))
continue;
xapic_id = kvm_xapic_id(apic);
x2apic_id = kvm_x2apic_id(apic);
/* Hotplug hack: see kvm_apic_match_physical_addr(), ... */
if ((apic_x2apic_mode(apic) || x2apic_id > 0xff) &&
x2apic_id <= new->max_apic_id)
new->phys_map[x2apic_id] = apic;
/*
* ... xAPIC ID of VCPUs with APIC ID > 0xff will wrap-around,
* prevent them from masking VCPUs with APIC ID <= 0xff.
*/
if (!apic_x2apic_mode(apic) && !new->phys_map[xapic_id])
new->phys_map[xapic_id] = apic;
ldr = kvm_lapic_get_reg(apic, APIC_LDR);
if (apic_x2apic_mode(apic)) {
new->mode |= KVM_APIC_MODE_X2APIC;
} else if (ldr) {
ldr = GET_APIC_LOGICAL_ID(ldr);
if (kvm_lapic_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_map_get_logical_dest(new, ldr, &cluster, &mask))
continue;
if (mask)
cluster[ffs(mask) - 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)
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_key_slow_dec_deferred(&apic_sw_disabled);
else
static_key_slow_inc(&apic_sw_disabled.key);
}
}
static inline void kvm_apic_set_xapic_id(struct kvm_lapic *apic, u8 id)
{
kvm_lapic_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)
{
kvm_lapic_set_reg(apic, APIC_LDR, id);
recalculate_apic_map(apic->vcpu->kvm);
}
static inline u32 kvm_apic_calc_x2apic_ldr(u32 id)
{
return ((id >> 4) << 16) | (1 << (id & 0xf));
}
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);
recalculate_apic_map(apic->vcpu->kvm);
}
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_lvt_vector(struct kvm_lapic *apic, int lvt_type)
{
return kvm_lapic_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 (!lapic_in_kernel(vcpu))
return;
/*
* 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.
*/
feat = kvm_find_cpuid_entry(apic->vcpu, 0x1, 0);
if (feat && (feat->ecx & (1 << (X86_FEATURE_X2APIC & 31))) &&
!ioapic_in_kernel(vcpu->kvm))
v |= APIC_LVR_DIRECTED_EOI;
kvm_lapic_set_reg(apic, APIC_LVR, v);
}
static const unsigned int apic_lvt_mask[KVM_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) + 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) {
pir_val = READ_ONCE(pir[i]);
irr_val = *((u32 *)(regs + APIC_IRR + i * 0x10));
if (pir_val) {
prev_irr_val = irr_val;
irr_val |= xchg(&pir[i], 0);
*((u32 *)(regs + APIC_IRR + i * 0x10)) = 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;
return __kvm_apic_update_irr(pir, apic->regs, max_irr);
}
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)
{
struct kvm_vcpu *vcpu;
vcpu = apic->vcpu;
if (unlikely(vcpu->arch.apicv_active)) {
/* need to update RVI */
apic_clear_vector(vec, apic->regs + APIC_IRR);
kvm_x86_ops->hwapic_irr_update(vcpu,
apic_find_highest_irr(apic));
} 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(vcpu->arch.apicv_active))
kvm_x86_ops->hwapic_isr_update(vcpu, 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(vcpu->arch.apicv_active))
kvm_x86_ops->hwapic_isr_update(vcpu,
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);
}
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)
{
int i;
struct kvm_apic_map *map;
struct kvm_vcpu *vcpu;
struct kvm_lapic_irq irq = {0};
int cluster_size = op_64_bit ? 64 : 32;
int count = 0;
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;
if (icr & APIC_DEST_MASK)
return -KVM_EINVAL;
if (icr & APIC_SHORT_MASK)
return -KVM_EINVAL;
rcu_read_lock();
map = rcu_dereference(kvm->arch.apic_map);
if (unlikely(!map)) {
count = -EOPNOTSUPP;
goto out;
}
if (min > map->max_apic_id)
goto out;
/* Bits above cluster_size are masked in the caller. */
for_each_set_bit(i, &ipi_bitmap_low,
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);
}
}
min += cluster_size;
if (min > map->max_apic_id)
goto out;
for_each_set_bit(i, &ipi_bitmap_high,
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);
}
}
out:
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 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);
}
static int apic_has_interrupt_for_ppr(struct kvm_lapic *apic, u32 ppr)
{
int highest_irr;
if (apic->vcpu->arch.apicv_active)
highest_irr = kvm_x86_ops->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;
apic_debug("vlapic %p, ppr 0x%x, isr 0x%x, isrv 0x%x",
apic, ppr, isr, isrv);
*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;
if (apic_x2apic_mode(apic))
return mda == kvm_x2apic_id(apic);
/*
* Hotplug hack: Make LAPIC in xAPIC mode also accept interrupts as if
* it were in x2APIC mode. Hotplugged VCPUs start in xAPIC mode and
* this allows unique addressing of VCPUs with APIC ID over 0xff.
* The 0xff condition is needed because writeable xAPIC ID.
*/
if (kvm_x2apic_id(apic) > 0xff && mda == kvm_x2apic_id(apic))
return true;
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:
apic_debug("Bad DFR vcpu %d: %08x\n",
apic->vcpu->vcpu_id, kvm_lapic_get_reg(apic, APIC_DFR));
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 short_hand, unsigned int dest, int dest_mode)
{
struct kvm_lapic *target = vcpu->arch.apic;
u32 mda = kvm_apic_mda(vcpu, 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;
}
}
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;
printk(KERN_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->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) {
*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 handler 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 destinaiton 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++;
/* fall through */
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
apic_clear_vector(vector, apic->regs + APIC_TMR);
}
if (vcpu->arch.apicv_active)
kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
else {
kvm_lapic_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:
result = 1;
kvm_make_request(KVM_REQ_SMI, vcpu);
kvm_vcpu_kick(vcpu);
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 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 (test_bit(vector, vcpu_to_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);
static void apic_send_ipi(struct kvm_lapic *apic)
{
u32 icr_low = kvm_lapic_get_reg(apic, APIC_ICR);
u32 icr_high = kvm_lapic_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) != 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_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, "
"msi_redir_hint 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, irq.msi_redir_hint);
kvm_irq_delivery_to_apic(apic->vcpu->kvm, apic, &irq, NULL);
}
static u32 apic_get_tmcct(struct kvm_lapic *apic)
{
ktime_t remaining, now;
s64 ns;
u32 tmcct;
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);
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_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_lapic_get_reg(apic, offset);
break;
case APIC_TASKPRI:
report_tpr_access(apic, false);
/* fall thru */
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);
}
int kvm_lapic_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;
}
EXPORT_SYMBOL_GPL(kvm_lapic_reg_read);
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);
apic_debug("timer divide count is 0x%x\n",
apic->divide_count);
}
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(
"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;
}
}
}
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)) {
hrtimer_cancel(&apic->lapic_timer.timer);
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);
}
}
static void apic_timer_expired(struct kvm_lapic *apic)
{
struct kvm_vcpu *vcpu = apic->vcpu;
struct swait_queue_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);
/*
* For x86, the atomic_inc() is serialized, thus
* using swait_active() is safe.
*/
if (swait_active(q))
swake_up_one(q);
if (apic_lvtt_tscdeadline(apic) || ktimer->hv_timer_in_use)
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_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 (vcpu->arch.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_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;
/* too early */
if (advance_expire_delta < 0) {
ns = -advance_expire_delta * 1000000ULL;
do_div(ns, vcpu->arch.virtual_tsc_khz);
timer_advance_ns -= min((u32)ns,
timer_advance_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 += min((u32)ns,
timer_advance_ns / LAPIC_TIMER_ADVANCE_ADJUST_STEP);
}
if (abs(advance_expire_delta) < LAPIC_TIMER_ADVANCE_ADJUST_DONE)
apic->lapic_timer.timer_advance_adjust_done = true;
if (unlikely(timer_advance_ns > 5000)) {
timer_advance_ns = 0;
apic->lapic_timer.timer_advance_adjust_done = true;
}
apic->lapic_timer.timer_advance_ns = timer_advance_ns;
}
void kvm_wait_lapic_expire(struct kvm_vcpu *vcpu)
{
struct kvm_lapic *apic = vcpu->arch.apic;
u64 guest_tsc, tsc_deadline;
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_read_l1_tsc(vcpu, rdtsc());
apic->lapic_timer.advance_expire_delta = guest_tsc - tsc_deadline;
if (guest_tsc < tsc_deadline)
__wait_lapic_expire(vcpu, tsc_deadline - guest_tsc);
if (unlikely(!apic->lapic_timer.timer_advance_adjust_done))
adjust_lapic_timer_advance(vcpu, apic->lapic_timer.advance_expire_delta);
}
EXPORT_SYMBOL_GPL(kvm_wait_lapic_expire);
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_PINNED);
} else
apic_timer_expired(apic);
local_irq_restore(flags);
}
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 = (u64)kvm_lapic_get_reg(apic, APIC_TMICT)
* APIC_BUS_CYCLE_NS * apic->divide_count;
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)
{
ktime_t now;
u64 tscl = rdtsc();
now = ktime_get();
apic->lapic_timer.period = (u64)kvm_lapic_get_reg(apic, APIC_TMICT)
* APIC_BUS_CYCLE_NS * apic->divide_count;
if (!apic->lapic_timer.period) {
apic->lapic_timer.tscdeadline = 0;
return false;
}
limit_periodic_timer_frequency(apic);
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_lapic_get_reg(apic, APIC_TMICT),
apic->lapic_timer.period,
ktime_to_ns(ktime_add_ns(now,
apic->lapic_timer.period)));
apic->lapic_timer.tscdeadline = kvm_read_l1_tsc(apic->vcpu, tscl) +
nsec_to_cycles(apic->vcpu, apic->lapic_timer.period);
apic->lapic_timer.target_expiration = ktime_add_ns(now, apic->lapic_timer.period);
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);
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_PINNED);
}
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;
}
EXPORT_SYMBOL_GPL(kvm_lapic_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);
kvm_x86_ops->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_x86_ops->set_hv_timer)
return false;
if (!ktimer->tscdeadline)
return false;
if (kvm_x86_ops->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);
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(swait_active(&vcpu->wq));
cancel_hv_timer(apic);
apic_timer_expired(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);
}
EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_hv_timer);
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();
}
EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_sw_timer);
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)
{
atomic_set(&apic->lapic_timer.pending, 0);
if ((apic_lvtt_period(apic) || apic_lvtt_oneshot(apic))
&& !set_target_expiration(apic))
return;
restart_apic_timer(apic);
}
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) {
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
atomic_dec(&apic->vcpu->kvm->arch.vapics_in_nmi_mode);
}
}
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_lapic_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_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;
u32 lvt_val;
for (i = 0; i < KVM_APIC_LVT_NUM; i++) {
lvt_val = kvm_lapic_get_reg(apic,
APIC_LVTT + 0x10 * i);
kvm_lapic_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 */
kvm_lapic_set_reg(apic, APIC_ICR, val & ~(1 << 12));
apic_send_ipi(apic);
break;
case APIC_ICR2:
if (!apic_x2apic_mode(apic))
val &= 0xff000000;
kvm_lapic_set_reg(apic, APIC_ICR2, val);
break;
case APIC_LVT0:
apic_manage_nmi_watchdog(apic, val);
/* fall through */
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];
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;
hrtimer_cancel(&apic->lapic_timer.timer);
kvm_lapic_set_reg(apic, APIC_TMICT, val);
start_apic_timer(apic);
break;
case APIC_TDCR: {
uint32_t old_divisor = apic->divide_count;
if (val & 4)
apic_debug("KVM_WRITE:TDCR %x\n", val);
kvm_lapic_set_reg(apic, APIC_TDCR, val);
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) {
apic_debug("KVM_WRITE:ESR not zero %x\n", val);
ret = 1;
}
break;
case APIC_SELF_IPI:
if (apic_x2apic_mode(apic)) {
kvm_lapic_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;
}
EXPORT_SYMBOL_GPL(kvm_lapic_reg_write);
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)) {
/* 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);
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)
{
u32 val = 0;
/* hw has done the conditional check and inst decode */
offset &= 0xff0;
kvm_lapic_reg_read(vcpu->arch.apic, offset, 4, &val);
/* TODO: optimize to just emulate side effect w/o one more write */
kvm_lapic_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 (!lapic_in_kernel(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 (!lapic_in_kernel(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;
apic_set_tpr(apic, ((cr8 & 0x0f) << 4)
| (kvm_lapic_get_reg(apic, APIC_TASKPRI) & 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;
if (!apic)
value |= MSR_IA32_APICBASE_BSP;
vcpu->arch.apic_base = value;
if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE)
kvm_update_cpuid(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_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) && (value & X2APIC_ENABLE))
kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE))
kvm_x86_ops->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)
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, bool init_event)
{
struct kvm_lapic *apic = vcpu->arch.apic;
int i;
if (!apic)
return;
apic_debug("%s\n", __func__);
/* Stop the timer in case it's a reset to an active apic */
hrtimer_cancel(&apic->lapic_timer.timer);
if (!init_event) {
kvm_lapic_set_base(vcpu, APIC_DEFAULT_PHYS_BASE |
MSR_IA32_APICBASE_ENABLE);
kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
}
kvm_apic_set_version(apic->vcpu);
for (i = 0; i < KVM_APIC_LVT_NUM; i++)
kvm_lapic_set_reg(apic, APIC_LVTT + 0x10 * 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_lapic_set_reg(apic, APIC_DFR, 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);
kvm_lapic_set_reg(apic, APIC_ICR, 0);
kvm_lapic_set_reg(apic, APIC_ICR2, 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);
}
apic->irr_pending = vcpu->arch.apicv_active;
apic->isr_count = vcpu->arch.apicv_active ? 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);
if (vcpu->arch.apicv_active) {
kvm_x86_ops->apicv_post_state_restore(vcpu);
kvm_x86_ops->hwapic_irr_update(vcpu, -1);
kvm_x86_ops->hwapic_isr_update(vcpu, -1);
}
vcpu->arch.apic_arb_prio = 0;
vcpu->arch.apic_attention = 0;
apic_debug("%s: vcpu=%p, id=0x%x, base_msr="
"0x%016" PRIx64 ", base_address=0x%0lx.\n", __func__,
vcpu, kvm_lapic_get_reg(apic, APIC_ID),
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 (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;
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)) {
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_debug("apic_init %d\n", vcpu->vcpu_id);
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;
hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
HRTIMER_MODE_ABS_PINNED);
apic->lapic_timer.timer.function = apic_timer_fn;
if (timer_advance_ns == -1) {
apic->lapic_timer.timer_advance_ns = 1000;
apic->lapic_timer.timer_advance_adjust_done = false;
} else {
apic->lapic_timer.timer_advance_ns = timer_advance_ns;
apic->lapic_timer.timer_advance_adjust_done = true;
}
/*
* 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;
static_key_slow_inc(&apic_sw_disabled.key); /* sw disabled at reset */
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;
u32 ppr;
if (!apic_enabled(apic))
return -1;
__apic_update_ppr(apic, &ppr);
return apic_has_interrupt_for_ppr(apic, ppr);
}
int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu)
{
u32 lvt0 = kvm_lapic_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 (atomic_read(&apic->lapic_timer.pending) > 0) {
kvm_apic_local_deliver(apic, APIC_LVTT);
if (apic_lvtt_tscdeadline(apic))
apic->lapic_timer.tscdeadline = 0;
if (apic_lvtt_oneshot(apic)) {
apic->lapic_timer.tscdeadline = 0;
apic->lapic_timer.target_expiration = 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;
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 (test_bit(vector, vcpu_to_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);
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 */
if (set)
*ldr = kvm_apic_calc_x2apic_ldr(*id);
}
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));
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;
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)
return r;
memcpy(vcpu->arch.apic->regs, s->regs, sizeof(*s));
recalculate_apic_map(vcpu->kvm);
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_lapic_get_reg(apic, APIC_LVT0));
update_divide_count(apic);
start_apic_timer(apic);
apic->irr_pending = true;
apic->isr_count = vcpu->arch.apicv_active ?
1 : count_vectors(apic->regs + APIC_ISR);
apic->highest_isr_cache = -1;
if (vcpu->arch.apicv_active) {
kvm_x86_ops->apicv_post_state_restore(vcpu);
kvm_x86_ops->hwapic_irr_update(vcpu,
apic_find_highest_irr(apic));
kvm_x86_ops->hwapic_isr_update(vcpu,
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))
return;
timer = &vcpu->arch.apic->lapic_timer.timer;
if (hrtimer_cancel(timer))
hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
}
/*
* 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;
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_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;
if (reg == APIC_ICR2)
return 1;
/* if this is ICR write vector before command */
if (reg == APIC_ICR)
kvm_lapic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
return kvm_lapic_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 (!lapic_in_kernel(vcpu) || !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 (kvm_lapic_reg_read(apic, reg, 4, &low))
return 1;
if (reg == APIC_ICR)
kvm_lapic_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 (!lapic_in_kernel(vcpu))
return 1;
/* if this is ICR write vector before command */
if (reg == APIC_ICR)
kvm_lapic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
return kvm_lapic_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 (!lapic_in_kernel(vcpu))
return 1;
if (kvm_lapic_reg_read(apic, reg, 4, &low))
return 1;
if (reg == APIC_ICR)
kvm_lapic_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, unsigned long len)
{
u64 addr = data & ~KVM_MSR_ENABLED;
struct gfn_to_hva_cache *ghc = &vcpu->arch.pv_eoi.data;
unsigned long new_len;
if (!IS_ALIGNED(addr, 4))
return 1;
vcpu->arch.pv_eoi.msr_val = data;
if (!pv_eoi_enabled(vcpu))
return 0;
if (addr == ghc->gpa && len <= ghc->len)
new_len = ghc->len;
else
new_len = len;
return kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, addr, new_len);
}
void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
{
struct kvm_lapic *apic = vcpu->arch.apic;
u8 sipi_vector;
unsigned long pe;
if (!lapic_in_kernel(vcpu) || !apic->pending_events)
return;
/*
* INITs are latched while in SMM. Because an SMM CPU cannot
* be in KVM_MP_STATE_INIT_RECEIVED state, just eat SIPIs
* and delay processing of INIT until the next RSM.
*/
if (is_smm(vcpu)) {
WARN_ON_ONCE(vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED);
if (test_bit(KVM_APIC_SIPI, &apic->pending_events))
clear_bit(KVM_APIC_SIPI, &apic->pending_events);
return;
}
pe = xchg(&apic->pending_events, 0);
if (test_bit(KVM_APIC_INIT, &pe)) {
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_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);
}
void kvm_lapic_exit(void)
{
static_key_deferred_flush(&apic_hw_disabled);
static_key_deferred_flush(&apic_sw_disabled);
}
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