qemu/hw/i386/kvm/clock.c

144 lines
3.7 KiB
C

/*
* QEMU KVM support, paravirtual clock device
*
* Copyright (C) 2011 Siemens AG
*
* Authors:
* Jan Kiszka <jan.kiszka@siemens.com>
*
* This work is licensed under the terms of the GNU GPL version 2.
* See the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu-common.h"
#include "sysemu/sysemu.h"
#include "sysemu/kvm.h"
#include "hw/sysbus.h"
#include "hw/kvm/clock.h"
#include <linux/kvm.h>
#include <linux/kvm_para.h>
typedef struct KVMClockState {
SysBusDevice busdev;
uint64_t clock;
bool clock_valid;
} KVMClockState;
static void kvmclock_pre_save(void *opaque)
{
KVMClockState *s = opaque;
struct kvm_clock_data data;
int ret;
if (s->clock_valid) {
return;
}
ret = kvm_vm_ioctl(kvm_state, KVM_GET_CLOCK, &data);
if (ret < 0) {
fprintf(stderr, "KVM_GET_CLOCK failed: %s\n", strerror(ret));
data.clock = 0;
}
s->clock = data.clock;
/*
* If the VM is stopped, declare the clock state valid to avoid re-reading
* it on next vmsave (which would return a different value). Will be reset
* when the VM is continued.
*/
s->clock_valid = !runstate_is_running();
}
static int kvmclock_post_load(void *opaque, int version_id)
{
KVMClockState *s = opaque;
struct kvm_clock_data data;
data.clock = s->clock;
data.flags = 0;
return kvm_vm_ioctl(kvm_state, KVM_SET_CLOCK, &data);
}
static void kvmclock_vm_state_change(void *opaque, int running,
RunState state)
{
KVMClockState *s = opaque;
CPUArchState *penv = first_cpu;
int cap_clock_ctrl = kvm_check_extension(kvm_state, KVM_CAP_KVMCLOCK_CTRL);
int ret;
if (running) {
s->clock_valid = false;
if (!cap_clock_ctrl) {
return;
}
for (penv = first_cpu; penv != NULL; penv = penv->next_cpu) {
ret = kvm_vcpu_ioctl(ENV_GET_CPU(penv), KVM_KVMCLOCK_CTRL, 0);
if (ret) {
if (ret != -EINVAL) {
fprintf(stderr, "%s: %s\n", __func__, strerror(-ret));
}
return;
}
}
}
}
static int kvmclock_init(SysBusDevice *dev)
{
KVMClockState *s = FROM_SYSBUS(KVMClockState, dev);
qemu_add_vm_change_state_handler(kvmclock_vm_state_change, s);
return 0;
}
static const VMStateDescription kvmclock_vmsd = {
.name = "kvmclock",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.pre_save = kvmclock_pre_save,
.post_load = kvmclock_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT64(clock, KVMClockState),
VMSTATE_END_OF_LIST()
}
};
static void kvmclock_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
k->init = kvmclock_init;
dc->no_user = 1;
dc->vmsd = &kvmclock_vmsd;
}
static const TypeInfo kvmclock_info = {
.name = "kvmclock",
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(KVMClockState),
.class_init = kvmclock_class_init,
};
/* Note: Must be called after VCPU initialization. */
void kvmclock_create(void)
{
if (kvm_enabled() &&
first_cpu->features[FEAT_KVM] & ((1ULL << KVM_FEATURE_CLOCKSOURCE) |
(1ULL << KVM_FEATURE_CLOCKSOURCE2))) {
sysbus_create_simple("kvmclock", -1, NULL);
}
}
static void kvmclock_register_types(void)
{
type_register_static(&kvmclock_info);
}
type_init(kvmclock_register_types)