/*
* 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 "hyperv.h"
#include <linux/kvm_host.h>
#include <linux/nospec.h>
#include <trace/events/kvm.h>
#include "trace.h"
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;
size_t size = ARRAY_SIZE(hv->hv_crash_param);
if (WARN_ON_ONCE(index >= size))
return -EINVAL;
*pdata = hv->hv_crash_param[array_index_nospec(index, size)];
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;
size_t size = ARRAY_SIZE(hv->hv_crash_param);
if (WARN_ON_ONCE(index >= size))
return -EINVAL;
hv->hv_crash_param[array_index_nospec(index, size)] = data;
return 0;
}
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: {
u64 gfn;
HV_REFERENCE_TSC_PAGE tsc_ref;
memset(&tsc_ref, 0, sizeof(tsc_ref));
hv->hv_tsc_page = data;
if (!(data & HV_X64_MSR_TSC_REFERENCE_ENABLE))
break;
gfn = data >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
if (kvm_write_guest(
kvm,
gfn << HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT,
&tsc_ref, sizeof(tsc_ref)))
return 1;
mark_page_dirty(kvm, gfn);
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;
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 =
div_u64(get_kernel_ns() + kvm->arch.kvmclock_offset, 100);
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;
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->lock);
r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
mutex_unlock(&vcpu->kvm->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->lock);
r = kvm_hv_get_msr_pw(vcpu, msr, pdata);
mutex_unlock(&vcpu->kvm->lock);
return r;
} else
return kvm_hv_get_msr(vcpu, msr, pdata);
}
bool kvm_hv_hypercall_enabled(struct kvm *kvm)
{
return kvm->arch.hyperv.hv_hypercall & HV_X64_MSR_HYPERCALL_ENABLE;
}
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 0;
}
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);
switch (code) {
case HV_X64_HV_NOTIFY_LONG_SPIN_WAIT:
kvm_vcpu_on_spin(vcpu);
break;
default:
res = HV_STATUS_INVALID_HYPERCALL_CODE;
break;
}
ret = res | (((u64)rep_done & 0xfff) << 32);
if (longmode) {
kvm_register_write(vcpu, VCPU_REGS_RAX, ret);
} else {
kvm_register_write(vcpu, VCPU_REGS_RDX, ret >> 32);
kvm_register_write(vcpu, VCPU_REGS_RAX, ret & 0xffffffff);
}
return 1;
}