mtd: nand: atmel: Relax tADL_min constraint

[mirror_ubuntu-artful-kernel.git] / arch / x86 / kvm / hyperv.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 <linux/sched/cputime.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 *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
{
        struct kvm_vcpu *vcpu = NULL;
        int i;

        if (vpidx < KVM_MAX_VCPUS)
                vcpu = kvm_get_vcpu(kvm, vpidx);
        if (vcpu && vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx)
                return vcpu;
        kvm_for_each_vcpu(i, vcpu, kvm)
                if (vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx)
                        return vcpu;
        return NULL;
}

static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
{
        struct kvm_vcpu *vcpu;
        struct kvm_vcpu_hv_synic *synic;

        vcpu = get_vcpu_by_vpidx(kvm, vpidx);
        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) && !host &&
                    !synic->dont_zero_synic_pages)
                        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) && !host &&
                    !synic->dont_zero_synic_pages)
                        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.shorthand = APIC_DEST_SELF;
        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, vcpu->arch.apic, &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 vpidx, u32 sint)
{
        struct kvm_vcpu_hv_synic *synic;

        synic = synic_get(kvm, vpidx);
        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 vpidx, u32 sint, int gsi)
{
        struct kvm_vcpu_hv_synic *synic;

        synic = synic_get(kvm, vpidx);
        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);
}

void kvm_hv_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
        struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);

        hv_vcpu->vp_index = kvm_vcpu_get_idx(vcpu);
}

int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
{
        struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);

        /*
         * Hyper-V SynIC auto EOI SINT's are
         * not compatible with APICV, so deactivate APICV
         */
        kvm_vcpu_deactivate_apicv(vcpu);
        synic->active = true;
        synic->dont_zero_synic_pages = dont_zero_synic_pages;
        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)
{
        u64 utime, stime;

        task_cputime_adjusted(current, &utime, &stime);

        return div_u64(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_VP_INDEX:
                if (!host)
                        return 1;
                hv->vp_index = (u32)data;
                break;
        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:
                data = hv->vp_index;
                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;
}