linux/arch/x86/kvm/hyperv.c
Paolo Bonzini 3f5ad8be37 KVM: hyperv: fix locking of struct kvm_hv fields
Introduce a new mutex to avoid an AB-BA deadlock between kvm->lock and
vcpu->mutex.  Protect accesses in kvm_hv_setup_tsc_page too, as suggested
by Roman.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-12-16 17:53:38 +01:00

1273 lines
32 KiB
C

/*
* KVM Microsoft Hyper-V emulation
*
* derived from arch/x86/kvm/x86.c
*
* Copyright (C) 2006 Qumranet, Inc.
* Copyright (C) 2008 Qumranet, Inc.
* Copyright IBM Corporation, 2008
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
* Copyright (C) 2015 Andrey Smetanin <asmetanin@virtuozzo.com>
*
* Authors:
* Avi Kivity <avi@qumranet.com>
* Yaniv Kamay <yaniv@qumranet.com>
* Amit Shah <amit.shah@qumranet.com>
* Ben-Ami Yassour <benami@il.ibm.com>
* Andrey Smetanin <asmetanin@virtuozzo.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "x86.h"
#include "lapic.h"
#include "ioapic.h"
#include "hyperv.h"
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <asm/apicdef.h>
#include <trace/events/kvm.h>
#include "trace.h"
static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
{
return atomic64_read(&synic->sint[sint]);
}
static inline int synic_get_sint_vector(u64 sint_value)
{
if (sint_value & HV_SYNIC_SINT_MASKED)
return -1;
return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
}
static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
int vector)
{
int i;
for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
return true;
}
return false;
}
static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
int vector)
{
int i;
u64 sint_value;
for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
sint_value = synic_read_sint(synic, i);
if (synic_get_sint_vector(sint_value) == vector &&
sint_value & HV_SYNIC_SINT_AUTO_EOI)
return true;
}
return false;
}
static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
u64 data, bool host)
{
int vector;
vector = data & HV_SYNIC_SINT_VECTOR_MASK;
if (vector < 16 && !host)
return 1;
/*
* Guest may configure multiple SINTs to use the same vector, so
* we maintain a bitmap of vectors handled by synic, and a
* bitmap of vectors with auto-eoi behavior. The bitmaps are
* updated here, and atomically queried on fast paths.
*/
atomic64_set(&synic->sint[sint], data);
if (synic_has_vector_connected(synic, vector))
__set_bit(vector, synic->vec_bitmap);
else
__clear_bit(vector, synic->vec_bitmap);
if (synic_has_vector_auto_eoi(synic, vector))
__set_bit(vector, synic->auto_eoi_bitmap);
else
__clear_bit(vector, synic->auto_eoi_bitmap);
/* Load SynIC vectors into EOI exit bitmap */
kvm_make_request(KVM_REQ_SCAN_IOAPIC, synic_to_vcpu(synic));
return 0;
}
static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vcpu_id)
{
struct kvm_vcpu *vcpu;
struct kvm_vcpu_hv_synic *synic;
if (vcpu_id >= atomic_read(&kvm->online_vcpus))
return NULL;
vcpu = kvm_get_vcpu(kvm, vcpu_id);
if (!vcpu)
return NULL;
synic = vcpu_to_synic(vcpu);
return (synic->active) ? synic : NULL;
}
static void synic_clear_sint_msg_pending(struct kvm_vcpu_hv_synic *synic,
u32 sint)
{
struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
struct page *page;
gpa_t gpa;
struct hv_message *msg;
struct hv_message_page *msg_page;
gpa = synic->msg_page & PAGE_MASK;
page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
if (is_error_page(page)) {
vcpu_err(vcpu, "Hyper-V SynIC can't get msg page, gpa 0x%llx\n",
gpa);
return;
}
msg_page = kmap_atomic(page);
msg = &msg_page->sint_message[sint];
msg->header.message_flags.msg_pending = 0;
kunmap_atomic(msg_page);
kvm_release_page_dirty(page);
kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
}
static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
struct kvm_vcpu_hv_stimer *stimer;
int gsi, idx, stimers_pending;
trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
if (synic->msg_page & HV_SYNIC_SIMP_ENABLE)
synic_clear_sint_msg_pending(synic, sint);
/* Try to deliver pending Hyper-V SynIC timers messages */
stimers_pending = 0;
for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
stimer = &hv_vcpu->stimer[idx];
if (stimer->msg_pending &&
(stimer->config & HV_STIMER_ENABLE) &&
HV_STIMER_SINT(stimer->config) == sint) {
set_bit(stimer->index,
hv_vcpu->stimer_pending_bitmap);
stimers_pending++;
}
}
if (stimers_pending)
kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
idx = srcu_read_lock(&kvm->irq_srcu);
gsi = atomic_read(&synic->sint_to_gsi[sint]);
if (gsi != -1)
kvm_notify_acked_gsi(kvm, gsi);
srcu_read_unlock(&kvm->irq_srcu, idx);
}
static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
{
struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
hv_vcpu->exit.u.synic.msr = msr;
hv_vcpu->exit.u.synic.control = synic->control;
hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
}
static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
u32 msr, u64 data, bool host)
{
struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
int ret;
if (!synic->active)
return 1;
trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
ret = 0;
switch (msr) {
case HV_X64_MSR_SCONTROL:
synic->control = data;
if (!host)
synic_exit(synic, msr);
break;
case HV_X64_MSR_SVERSION:
if (!host) {
ret = 1;
break;
}
synic->version = data;
break;
case HV_X64_MSR_SIEFP:
if (data & HV_SYNIC_SIEFP_ENABLE)
if (kvm_clear_guest(vcpu->kvm,
data & PAGE_MASK, PAGE_SIZE)) {
ret = 1;
break;
}
synic->evt_page = data;
if (!host)
synic_exit(synic, msr);
break;
case HV_X64_MSR_SIMP:
if (data & HV_SYNIC_SIMP_ENABLE)
if (kvm_clear_guest(vcpu->kvm,
data & PAGE_MASK, PAGE_SIZE)) {
ret = 1;
break;
}
synic->msg_page = data;
if (!host)
synic_exit(synic, msr);
break;
case HV_X64_MSR_EOM: {
int i;
for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
kvm_hv_notify_acked_sint(vcpu, i);
break;
}
case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
break;
default:
ret = 1;
break;
}
return ret;
}
static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata)
{
int ret;
if (!synic->active)
return 1;
ret = 0;
switch (msr) {
case HV_X64_MSR_SCONTROL:
*pdata = synic->control;
break;
case HV_X64_MSR_SVERSION:
*pdata = synic->version;
break;
case HV_X64_MSR_SIEFP:
*pdata = synic->evt_page;
break;
case HV_X64_MSR_SIMP:
*pdata = synic->msg_page;
break;
case HV_X64_MSR_EOM:
*pdata = 0;
break;
case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
*pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
break;
default:
ret = 1;
break;
}
return ret;
}
static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
{
struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
struct kvm_lapic_irq irq;
int ret, vector;
if (sint >= ARRAY_SIZE(synic->sint))
return -EINVAL;
vector = synic_get_sint_vector(synic_read_sint(synic, sint));
if (vector < 0)
return -ENOENT;
memset(&irq, 0, sizeof(irq));
irq.dest_id = kvm_apic_id(vcpu->arch.apic);
irq.dest_mode = APIC_DEST_PHYSICAL;
irq.delivery_mode = APIC_DM_FIXED;
irq.vector = vector;
irq.level = 1;
ret = kvm_irq_delivery_to_apic(vcpu->kvm, NULL, &irq, NULL);
trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
return ret;
}
int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vcpu_id, u32 sint)
{
struct kvm_vcpu_hv_synic *synic;
synic = synic_get(kvm, vcpu_id);
if (!synic)
return -EINVAL;
return synic_set_irq(synic, sint);
}
void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
{
struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
int i;
trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
kvm_hv_notify_acked_sint(vcpu, i);
}
static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vcpu_id, u32 sint, int gsi)
{
struct kvm_vcpu_hv_synic *synic;
synic = synic_get(kvm, vcpu_id);
if (!synic)
return -EINVAL;
if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
return -EINVAL;
atomic_set(&synic->sint_to_gsi[sint], gsi);
return 0;
}
void kvm_hv_irq_routing_update(struct kvm *kvm)
{
struct kvm_irq_routing_table *irq_rt;
struct kvm_kernel_irq_routing_entry *e;
u32 gsi;
irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
lockdep_is_held(&kvm->irq_lock));
for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
if (e->type == KVM_IRQ_ROUTING_HV_SINT)
kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
e->hv_sint.sint, gsi);
}
}
}
static void synic_init(struct kvm_vcpu_hv_synic *synic)
{
int i;
memset(synic, 0, sizeof(*synic));
synic->version = HV_SYNIC_VERSION_1;
for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
atomic_set(&synic->sint_to_gsi[i], -1);
}
}
static u64 get_time_ref_counter(struct kvm *kvm)
{
struct kvm_hv *hv = &kvm->arch.hyperv;
struct kvm_vcpu *vcpu;
u64 tsc;
/*
* The guest has not set up the TSC page or the clock isn't
* stable, fall back to get_kvmclock_ns.
*/
if (!hv->tsc_ref.tsc_sequence)
return div_u64(get_kvmclock_ns(kvm), 100);
vcpu = kvm_get_vcpu(kvm, 0);
tsc = kvm_read_l1_tsc(vcpu, rdtsc());
return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
+ hv->tsc_ref.tsc_offset;
}
static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
bool vcpu_kick)
{
struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
set_bit(stimer->index,
vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
if (vcpu_kick)
kvm_vcpu_kick(vcpu);
}
static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
{
struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
trace_kvm_hv_stimer_cleanup(stimer_to_vcpu(stimer)->vcpu_id,
stimer->index);
hrtimer_cancel(&stimer->timer);
clear_bit(stimer->index,
vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
stimer->msg_pending = false;
stimer->exp_time = 0;
}
static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
{
struct kvm_vcpu_hv_stimer *stimer;
stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
trace_kvm_hv_stimer_callback(stimer_to_vcpu(stimer)->vcpu_id,
stimer->index);
stimer_mark_pending(stimer, true);
return HRTIMER_NORESTART;
}
/*
* stimer_start() assumptions:
* a) stimer->count is not equal to 0
* b) stimer->config has HV_STIMER_ENABLE flag
*/
static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
{
u64 time_now;
ktime_t ktime_now;
time_now = get_time_ref_counter(stimer_to_vcpu(stimer)->kvm);
ktime_now = ktime_get();
if (stimer->config & HV_STIMER_PERIODIC) {
if (stimer->exp_time) {
if (time_now >= stimer->exp_time) {
u64 remainder;
div64_u64_rem(time_now - stimer->exp_time,
stimer->count, &remainder);
stimer->exp_time =
time_now + (stimer->count - remainder);
}
} else
stimer->exp_time = time_now + stimer->count;
trace_kvm_hv_stimer_start_periodic(
stimer_to_vcpu(stimer)->vcpu_id,
stimer->index,
time_now, stimer->exp_time);
hrtimer_start(&stimer->timer,
ktime_add_ns(ktime_now,
100 * (stimer->exp_time - time_now)),
HRTIMER_MODE_ABS);
return 0;
}
stimer->exp_time = stimer->count;
if (time_now >= stimer->count) {
/*
* Expire timer according to Hypervisor Top-Level Functional
* specification v4(15.3.1):
* "If a one shot is enabled and the specified count is in
* the past, it will expire immediately."
*/
stimer_mark_pending(stimer, false);
return 0;
}
trace_kvm_hv_stimer_start_one_shot(stimer_to_vcpu(stimer)->vcpu_id,
stimer->index,
time_now, stimer->count);
hrtimer_start(&stimer->timer,
ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
HRTIMER_MODE_ABS);
return 0;
}
static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
bool host)
{
trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id,
stimer->index, config, host);
stimer_cleanup(stimer);
if ((stimer->config & HV_STIMER_ENABLE) && HV_STIMER_SINT(config) == 0)
config &= ~HV_STIMER_ENABLE;
stimer->config = config;
stimer_mark_pending(stimer, false);
return 0;
}
static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
bool host)
{
trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id,
stimer->index, count, host);
stimer_cleanup(stimer);
stimer->count = count;
if (stimer->count == 0)
stimer->config &= ~HV_STIMER_ENABLE;
else if (stimer->config & HV_STIMER_AUTOENABLE)
stimer->config |= HV_STIMER_ENABLE;
stimer_mark_pending(stimer, false);
return 0;
}
static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
{
*pconfig = stimer->config;
return 0;
}
static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
{
*pcount = stimer->count;
return 0;
}
static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
struct hv_message *src_msg)
{
struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
struct page *page;
gpa_t gpa;
struct hv_message *dst_msg;
int r;
struct hv_message_page *msg_page;
if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
return -ENOENT;
gpa = synic->msg_page & PAGE_MASK;
page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
if (is_error_page(page))
return -EFAULT;
msg_page = kmap_atomic(page);
dst_msg = &msg_page->sint_message[sint];
if (sync_cmpxchg(&dst_msg->header.message_type, HVMSG_NONE,
src_msg->header.message_type) != HVMSG_NONE) {
dst_msg->header.message_flags.msg_pending = 1;
r = -EAGAIN;
} else {
memcpy(&dst_msg->u.payload, &src_msg->u.payload,
src_msg->header.payload_size);
dst_msg->header.message_type = src_msg->header.message_type;
dst_msg->header.payload_size = src_msg->header.payload_size;
r = synic_set_irq(synic, sint);
if (r >= 1)
r = 0;
else if (r == 0)
r = -EFAULT;
}
kunmap_atomic(msg_page);
kvm_release_page_dirty(page);
kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
return r;
}
static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
{
struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
struct hv_message *msg = &stimer->msg;
struct hv_timer_message_payload *payload =
(struct hv_timer_message_payload *)&msg->u.payload;
payload->expiration_time = stimer->exp_time;
payload->delivery_time = get_time_ref_counter(vcpu->kvm);
return synic_deliver_msg(vcpu_to_synic(vcpu),
HV_STIMER_SINT(stimer->config), msg);
}
static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
{
int r;
stimer->msg_pending = true;
r = stimer_send_msg(stimer);
trace_kvm_hv_stimer_expiration(stimer_to_vcpu(stimer)->vcpu_id,
stimer->index, r);
if (!r) {
stimer->msg_pending = false;
if (!(stimer->config & HV_STIMER_PERIODIC))
stimer->config &= ~HV_STIMER_ENABLE;
}
}
void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
struct kvm_vcpu_hv_stimer *stimer;
u64 time_now, exp_time;
int i;
for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
stimer = &hv_vcpu->stimer[i];
if (stimer->config & HV_STIMER_ENABLE) {
exp_time = stimer->exp_time;
if (exp_time) {
time_now =
get_time_ref_counter(vcpu->kvm);
if (time_now >= exp_time)
stimer_expiration(stimer);
}
if ((stimer->config & HV_STIMER_ENABLE) &&
stimer->count)
stimer_start(stimer);
else
stimer_cleanup(stimer);
}
}
}
void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
int i;
for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
stimer_cleanup(&hv_vcpu->stimer[i]);
}
static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
{
struct hv_message *msg = &stimer->msg;
struct hv_timer_message_payload *payload =
(struct hv_timer_message_payload *)&msg->u.payload;
memset(&msg->header, 0, sizeof(msg->header));
msg->header.message_type = HVMSG_TIMER_EXPIRED;
msg->header.payload_size = sizeof(*payload);
payload->timer_index = stimer->index;
payload->expiration_time = 0;
payload->delivery_time = 0;
}
static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
{
memset(stimer, 0, sizeof(*stimer));
stimer->index = timer_index;
hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
stimer->timer.function = stimer_timer_callback;
stimer_prepare_msg(stimer);
}
void kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
int i;
synic_init(&hv_vcpu->synic);
bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
stimer_init(&hv_vcpu->stimer[i], i);
}
int kvm_hv_activate_synic(struct kvm_vcpu *vcpu)
{
/*
* Hyper-V SynIC auto EOI SINT's are
* not compatible with APICV, so deactivate APICV
*/
kvm_vcpu_deactivate_apicv(vcpu);
vcpu_to_synic(vcpu)->active = true;
return 0;
}
static bool kvm_hv_msr_partition_wide(u32 msr)
{
bool r = false;
switch (msr) {
case HV_X64_MSR_GUEST_OS_ID:
case HV_X64_MSR_HYPERCALL:
case HV_X64_MSR_REFERENCE_TSC:
case HV_X64_MSR_TIME_REF_COUNT:
case HV_X64_MSR_CRASH_CTL:
case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
case HV_X64_MSR_RESET:
r = true;
break;
}
return r;
}
static int kvm_hv_msr_get_crash_data(struct kvm_vcpu *vcpu,
u32 index, u64 *pdata)
{
struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
if (WARN_ON_ONCE(index >= ARRAY_SIZE(hv->hv_crash_param)))
return -EINVAL;
*pdata = hv->hv_crash_param[index];
return 0;
}
static int kvm_hv_msr_get_crash_ctl(struct kvm_vcpu *vcpu, u64 *pdata)
{
struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
*pdata = hv->hv_crash_ctl;
return 0;
}
static int kvm_hv_msr_set_crash_ctl(struct kvm_vcpu *vcpu, u64 data, bool host)
{
struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
if (host)
hv->hv_crash_ctl = data & HV_X64_MSR_CRASH_CTL_NOTIFY;
if (!host && (data & HV_X64_MSR_CRASH_CTL_NOTIFY)) {
vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
hv->hv_crash_param[0],
hv->hv_crash_param[1],
hv->hv_crash_param[2],
hv->hv_crash_param[3],
hv->hv_crash_param[4]);
/* Send notification about crash to user space */
kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
}
return 0;
}
static int kvm_hv_msr_set_crash_data(struct kvm_vcpu *vcpu,
u32 index, u64 data)
{
struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
if (WARN_ON_ONCE(index >= ARRAY_SIZE(hv->hv_crash_param)))
return -EINVAL;
hv->hv_crash_param[index] = data;
return 0;
}
/*
* The kvmclock and Hyper-V TSC page use similar formulas, and converting
* between them is possible:
*
* kvmclock formula:
* nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
* + system_time
*
* Hyper-V formula:
* nsec/100 = ticks * scale / 2^64 + offset
*
* When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
* By dividing the kvmclock formula by 100 and equating what's left we get:
* ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
* scale / 2^64 = tsc_to_system_mul * 2^(tsc_shift-32) / 100
* scale = tsc_to_system_mul * 2^(32+tsc_shift) / 100
*
* Now expand the kvmclock formula and divide by 100:
* nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
* - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
* + system_time
* nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
* - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
* + system_time / 100
*
* Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
* nsec/100 = ticks * scale / 2^64
* - tsc_timestamp * scale / 2^64
* + system_time / 100
*
* Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
* offset = system_time / 100 - tsc_timestamp * scale / 2^64
*
* These two equivalencies are implemented in this function.
*/
static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
HV_REFERENCE_TSC_PAGE *tsc_ref)
{
u64 max_mul;
if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
return false;
/*
* check if scale would overflow, if so we use the time ref counter
* tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
* tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
* tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
*/
max_mul = 100ull << (32 - hv_clock->tsc_shift);
if (hv_clock->tsc_to_system_mul >= max_mul)
return false;
/*
* Otherwise compute the scale and offset according to the formulas
* derived above.
*/
tsc_ref->tsc_scale =
mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
hv_clock->tsc_to_system_mul,
100);
tsc_ref->tsc_offset = hv_clock->system_time;
do_div(tsc_ref->tsc_offset, 100);
tsc_ref->tsc_offset -=
mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
return true;
}
void kvm_hv_setup_tsc_page(struct kvm *kvm,
struct pvclock_vcpu_time_info *hv_clock)
{
struct kvm_hv *hv = &kvm->arch.hyperv;
u32 tsc_seq;
u64 gfn;
BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
BUILD_BUG_ON(offsetof(HV_REFERENCE_TSC_PAGE, tsc_sequence) != 0);
if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
return;
mutex_lock(&kvm->arch.hyperv.hv_lock);
if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
goto out_unlock;
gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
/*
* Because the TSC parameters only vary when there is a
* change in the master clock, do not bother with caching.
*/
if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
&tsc_seq, sizeof(tsc_seq))))
goto out_unlock;
/*
* While we're computing and writing the parameters, force the
* guest to use the time reference count MSR.
*/
hv->tsc_ref.tsc_sequence = 0;
if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
&hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
goto out_unlock;
if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
goto out_unlock;
/* Ensure sequence is zero before writing the rest of the struct. */
smp_wmb();
if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
goto out_unlock;
/*
* Now switch to the TSC page mechanism by writing the sequence.
*/
tsc_seq++;
if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
tsc_seq = 1;
/* Write the struct entirely before the non-zero sequence. */
smp_wmb();
hv->tsc_ref.tsc_sequence = tsc_seq;
kvm_write_guest(kvm, gfn_to_gpa(gfn),
&hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence));
out_unlock:
mutex_unlock(&kvm->arch.hyperv.hv_lock);
}
static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
bool host)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_hv *hv = &kvm->arch.hyperv;
switch (msr) {
case HV_X64_MSR_GUEST_OS_ID:
hv->hv_guest_os_id = data;
/* setting guest os id to zero disables hypercall page */
if (!hv->hv_guest_os_id)
hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
break;
case HV_X64_MSR_HYPERCALL: {
u64 gfn;
unsigned long addr;
u8 instructions[4];
/* if guest os id is not set hypercall should remain disabled */
if (!hv->hv_guest_os_id)
break;
if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
hv->hv_hypercall = data;
break;
}
gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
addr = gfn_to_hva(kvm, gfn);
if (kvm_is_error_hva(addr))
return 1;
kvm_x86_ops->patch_hypercall(vcpu, instructions);
((unsigned char *)instructions)[3] = 0xc3; /* ret */
if (__copy_to_user((void __user *)addr, instructions, 4))
return 1;
hv->hv_hypercall = data;
mark_page_dirty(kvm, gfn);
break;
}
case HV_X64_MSR_REFERENCE_TSC:
hv->hv_tsc_page = data;
if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)
kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
break;
case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
return kvm_hv_msr_set_crash_data(vcpu,
msr - HV_X64_MSR_CRASH_P0,
data);
case HV_X64_MSR_CRASH_CTL:
return kvm_hv_msr_set_crash_ctl(vcpu, data, host);
case HV_X64_MSR_RESET:
if (data == 1) {
vcpu_debug(vcpu, "hyper-v reset requested\n");
kvm_make_request(KVM_REQ_HV_RESET, vcpu);
}
break;
default:
vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
msr, data);
return 1;
}
return 0;
}
/* Calculate cpu time spent by current task in 100ns units */
static u64 current_task_runtime_100ns(void)
{
cputime_t utime, stime;
task_cputime_adjusted(current, &utime, &stime);
return div_u64(cputime_to_nsecs(utime + stime), 100);
}
static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
{
struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
switch (msr) {
case HV_X64_MSR_APIC_ASSIST_PAGE: {
u64 gfn;
unsigned long addr;
if (!(data & HV_X64_MSR_APIC_ASSIST_PAGE_ENABLE)) {
hv->hv_vapic = data;
if (kvm_lapic_enable_pv_eoi(vcpu, 0))
return 1;
break;
}
gfn = data >> HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT;
addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
if (kvm_is_error_hva(addr))
return 1;
if (__clear_user((void __user *)addr, PAGE_SIZE))
return 1;
hv->hv_vapic = data;
kvm_vcpu_mark_page_dirty(vcpu, gfn);
if (kvm_lapic_enable_pv_eoi(vcpu,
gfn_to_gpa(gfn) | KVM_MSR_ENABLED))
return 1;
break;
}
case HV_X64_MSR_EOI:
return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
case HV_X64_MSR_ICR:
return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
case HV_X64_MSR_TPR:
return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
case HV_X64_MSR_VP_RUNTIME:
if (!host)
return 1;
hv->runtime_offset = data - current_task_runtime_100ns();
break;
case HV_X64_MSR_SCONTROL:
case HV_X64_MSR_SVERSION:
case HV_X64_MSR_SIEFP:
case HV_X64_MSR_SIMP:
case HV_X64_MSR_EOM:
case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
return synic_set_msr(vcpu_to_synic(vcpu), msr, data, host);
case HV_X64_MSR_STIMER0_CONFIG:
case HV_X64_MSR_STIMER1_CONFIG:
case HV_X64_MSR_STIMER2_CONFIG:
case HV_X64_MSR_STIMER3_CONFIG: {
int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
return stimer_set_config(vcpu_to_stimer(vcpu, timer_index),
data, host);
}
case HV_X64_MSR_STIMER0_COUNT:
case HV_X64_MSR_STIMER1_COUNT:
case HV_X64_MSR_STIMER2_COUNT:
case HV_X64_MSR_STIMER3_COUNT: {
int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
return stimer_set_count(vcpu_to_stimer(vcpu, timer_index),
data, host);
}
default:
vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
msr, data);
return 1;
}
return 0;
}
static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
u64 data = 0;
struct kvm *kvm = vcpu->kvm;
struct kvm_hv *hv = &kvm->arch.hyperv;
switch (msr) {
case HV_X64_MSR_GUEST_OS_ID:
data = hv->hv_guest_os_id;
break;
case HV_X64_MSR_HYPERCALL:
data = hv->hv_hypercall;
break;
case HV_X64_MSR_TIME_REF_COUNT:
data = get_time_ref_counter(kvm);
break;
case HV_X64_MSR_REFERENCE_TSC:
data = hv->hv_tsc_page;
break;
case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
return kvm_hv_msr_get_crash_data(vcpu,
msr - HV_X64_MSR_CRASH_P0,
pdata);
case HV_X64_MSR_CRASH_CTL:
return kvm_hv_msr_get_crash_ctl(vcpu, pdata);
case HV_X64_MSR_RESET:
data = 0;
break;
default:
vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
return 1;
}
*pdata = data;
return 0;
}
static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
u64 data = 0;
struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
switch (msr) {
case HV_X64_MSR_VP_INDEX: {
int r;
struct kvm_vcpu *v;
kvm_for_each_vcpu(r, v, vcpu->kvm) {
if (v == vcpu) {
data = r;
break;
}
}
break;
}
case HV_X64_MSR_EOI:
return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
case HV_X64_MSR_ICR:
return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
case HV_X64_MSR_TPR:
return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
case HV_X64_MSR_APIC_ASSIST_PAGE:
data = hv->hv_vapic;
break;
case HV_X64_MSR_VP_RUNTIME:
data = current_task_runtime_100ns() + hv->runtime_offset;
break;
case HV_X64_MSR_SCONTROL:
case HV_X64_MSR_SVERSION:
case HV_X64_MSR_SIEFP:
case HV_X64_MSR_SIMP:
case HV_X64_MSR_EOM:
case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
return synic_get_msr(vcpu_to_synic(vcpu), msr, pdata);
case HV_X64_MSR_STIMER0_CONFIG:
case HV_X64_MSR_STIMER1_CONFIG:
case HV_X64_MSR_STIMER2_CONFIG:
case HV_X64_MSR_STIMER3_CONFIG: {
int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
return stimer_get_config(vcpu_to_stimer(vcpu, timer_index),
pdata);
}
case HV_X64_MSR_STIMER0_COUNT:
case HV_X64_MSR_STIMER1_COUNT:
case HV_X64_MSR_STIMER2_COUNT:
case HV_X64_MSR_STIMER3_COUNT: {
int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
return stimer_get_count(vcpu_to_stimer(vcpu, timer_index),
pdata);
}
default:
vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
return 1;
}
*pdata = data;
return 0;
}
int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
{
if (kvm_hv_msr_partition_wide(msr)) {
int r;
mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
return r;
} else
return kvm_hv_set_msr(vcpu, msr, data, host);
}
int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
if (kvm_hv_msr_partition_wide(msr)) {
int r;
mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
r = kvm_hv_get_msr_pw(vcpu, msr, pdata);
mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
return r;
} else
return kvm_hv_get_msr(vcpu, msr, pdata);
}
bool kvm_hv_hypercall_enabled(struct kvm *kvm)
{
return READ_ONCE(kvm->arch.hyperv.hv_hypercall) & HV_X64_MSR_HYPERCALL_ENABLE;
}
static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
{
bool longmode;
longmode = is_64_bit_mode(vcpu);
if (longmode)
kvm_register_write(vcpu, VCPU_REGS_RAX, result);
else {
kvm_register_write(vcpu, VCPU_REGS_RDX, result >> 32);
kvm_register_write(vcpu, VCPU_REGS_RAX, result & 0xffffffff);
}
}
static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
kvm_hv_hypercall_set_result(vcpu, run->hyperv.u.hcall.result);
return 1;
}
int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
{
u64 param, ingpa, outgpa, ret;
uint16_t code, rep_idx, rep_cnt, res = HV_STATUS_SUCCESS, rep_done = 0;
bool fast, longmode;
/*
* hypercall generates UD from non zero cpl and real mode
* per HYPER-V spec
*/
if (kvm_x86_ops->get_cpl(vcpu) != 0 || !is_protmode(vcpu)) {
kvm_queue_exception(vcpu, UD_VECTOR);
return 1;
}
longmode = is_64_bit_mode(vcpu);
if (!longmode) {
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
}
#ifdef CONFIG_X86_64
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
#endif
code = param & 0xffff;
fast = (param >> 16) & 0x1;
rep_cnt = (param >> 32) & 0xfff;
rep_idx = (param >> 48) & 0xfff;
trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
/* Hypercall continuation is not supported yet */
if (rep_cnt || rep_idx) {
res = HV_STATUS_INVALID_HYPERCALL_CODE;
goto set_result;
}
switch (code) {
case HVCALL_NOTIFY_LONG_SPIN_WAIT:
kvm_vcpu_on_spin(vcpu);
break;
case HVCALL_POST_MESSAGE:
case HVCALL_SIGNAL_EVENT:
/* don't bother userspace if it has no way to handle it */
if (!vcpu_to_synic(vcpu)->active) {
res = HV_STATUS_INVALID_HYPERCALL_CODE;
break;
}
vcpu->run->exit_reason = KVM_EXIT_HYPERV;
vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
vcpu->run->hyperv.u.hcall.input = param;
vcpu->run->hyperv.u.hcall.params[0] = ingpa;
vcpu->run->hyperv.u.hcall.params[1] = outgpa;
vcpu->arch.complete_userspace_io =
kvm_hv_hypercall_complete_userspace;
return 0;
default:
res = HV_STATUS_INVALID_HYPERCALL_CODE;
break;
}
set_result:
ret = res | (((u64)rep_done & 0xfff) << 32);
kvm_hv_hypercall_set_result(vcpu, ret);
return 1;
}