/* * 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. * */ #include "qemu-common.h" #include "sysemu.h" #include "sysbus.h" #include "kvm.h" #include "kvmclock.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; if (running) { s->clock_valid = false; } } 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 SysBusDeviceInfo kvmclock_info = { .qdev.name = "kvmclock", .qdev.size = sizeof(KVMClockState), .qdev.vmsd = &kvmclock_vmsd, .qdev.no_user = 1, .init = kvmclock_init, }; /* Note: Must be called after VCPU initialization. */ void kvmclock_create(void) { if (kvm_enabled() && first_cpu->cpuid_kvm_features & ((1ULL << KVM_FEATURE_CLOCKSOURCE) | (1ULL << KVM_FEATURE_CLOCKSOURCE2))) { sysbus_create_simple("kvmclock", -1, NULL); } } static void kvmclock_register_device(void) { if (kvm_enabled()) { sysbus_register_withprop(&kvmclock_info); } } device_init(kvmclock_register_device);