2 * QEMU KVM support, paravirtual clock device
4 * Copyright (C) 2011 Siemens AG
7 * Jan Kiszka <jan.kiszka@siemens.com>
9 * This work is licensed under the terms of the GNU GPL version 2.
10 * See the COPYING file in the top-level directory.
12 * Contributions after 2012-01-13 are licensed under the terms of the
13 * GNU GPL, version 2 or (at your option) any later version.
16 #include "qemu-common.h"
19 #include "hw/sysbus.h"
20 #include "hw/kvm/clock.h"
22 #include <linux/kvm.h>
23 #include <linux/kvm_para.h>
25 typedef struct KVMClockState {
31 static void kvmclock_pre_save(void *opaque)
33 KVMClockState *s = opaque;
34 struct kvm_clock_data data;
40 ret = kvm_vm_ioctl(kvm_state, KVM_GET_CLOCK, &data);
42 fprintf(stderr, "KVM_GET_CLOCK failed: %s\n", strerror(ret));
45 s->clock = data.clock;
47 * If the VM is stopped, declare the clock state valid to avoid re-reading
48 * it on next vmsave (which would return a different value). Will be reset
49 * when the VM is continued.
51 s->clock_valid = !runstate_is_running();
54 static int kvmclock_post_load(void *opaque, int version_id)
56 KVMClockState *s = opaque;
57 struct kvm_clock_data data;
59 data.clock = s->clock;
61 return kvm_vm_ioctl(kvm_state, KVM_SET_CLOCK, &data);
64 static void kvmclock_vm_state_change(void *opaque, int running,
67 KVMClockState *s = opaque;
68 CPUArchState *penv = first_cpu;
69 int cap_clock_ctrl = kvm_check_extension(kvm_state, KVM_CAP_KVMCLOCK_CTRL);
73 s->clock_valid = false;
75 if (!cap_clock_ctrl) {
78 for (penv = first_cpu; penv != NULL; penv = penv->next_cpu) {
79 ret = kvm_vcpu_ioctl(penv, KVM_KVMCLOCK_CTRL, 0);
82 fprintf(stderr, "%s: %s\n", __func__, strerror(-ret));
90 static int kvmclock_init(SysBusDevice *dev)
92 KVMClockState *s = FROM_SYSBUS(KVMClockState, dev);
94 qemu_add_vm_change_state_handler(kvmclock_vm_state_change, s);
98 static const VMStateDescription kvmclock_vmsd = {
101 .minimum_version_id = 1,
102 .minimum_version_id_old = 1,
103 .pre_save = kvmclock_pre_save,
104 .post_load = kvmclock_post_load,
105 .fields = (VMStateField[]) {
106 VMSTATE_UINT64(clock, KVMClockState),
107 VMSTATE_END_OF_LIST()
111 static void kvmclock_class_init(ObjectClass *klass, void *data)
113 DeviceClass *dc = DEVICE_CLASS(klass);
114 SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
116 k->init = kvmclock_init;
118 dc->vmsd = &kvmclock_vmsd;
121 static TypeInfo kvmclock_info = {
123 .parent = TYPE_SYS_BUS_DEVICE,
124 .instance_size = sizeof(KVMClockState),
125 .class_init = kvmclock_class_init,
128 /* Note: Must be called after VCPU initialization. */
129 void kvmclock_create(void)
132 first_cpu->cpuid_kvm_features & ((1ULL << KVM_FEATURE_CLOCKSOURCE) |
133 (1ULL << KVM_FEATURE_CLOCKSOURCE2))) {
134 sysbus_create_simple("kvmclock", -1, NULL);
138 static void kvmclock_register_types(void)
140 type_register_static(&kvmclock_info);
143 type_init(kvmclock_register_types)