118 lines
2.7 KiB
C
118 lines
2.7 KiB
C
/*
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* QEMU KVM support, paravirtual clock device
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*
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* Copyright (C) 2011 Siemens AG
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*
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* Authors:
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* Jan Kiszka <jan.kiszka@siemens.com>
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*
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* This work is licensed under the terms of the GNU GPL version 2.
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* See the COPYING file in the top-level directory.
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*
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*/
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#include "qemu-common.h"
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#include "sysemu.h"
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#include "sysbus.h"
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#include "kvm.h"
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#include "kvmclock.h"
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#include <linux/kvm.h>
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#include <linux/kvm_para.h>
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typedef struct KVMClockState {
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SysBusDevice busdev;
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uint64_t clock;
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bool clock_valid;
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} KVMClockState;
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static void kvmclock_pre_save(void *opaque)
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{
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KVMClockState *s = opaque;
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struct kvm_clock_data data;
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int ret;
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if (s->clock_valid) {
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return;
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}
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ret = kvm_vm_ioctl(kvm_state, KVM_GET_CLOCK, &data);
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if (ret < 0) {
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fprintf(stderr, "KVM_GET_CLOCK failed: %s\n", strerror(ret));
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data.clock = 0;
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}
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s->clock = data.clock;
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/*
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* If the VM is stopped, declare the clock state valid to avoid re-reading
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* it on next vmsave (which would return a different value). Will be reset
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* when the VM is continued.
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*/
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s->clock_valid = !vm_running;
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}
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static int kvmclock_post_load(void *opaque, int version_id)
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{
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KVMClockState *s = opaque;
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struct kvm_clock_data data;
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data.clock = s->clock;
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data.flags = 0;
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return kvm_vm_ioctl(kvm_state, KVM_SET_CLOCK, &data);
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}
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static void kvmclock_vm_state_change(void *opaque, int running, int reason)
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{
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KVMClockState *s = opaque;
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if (running) {
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s->clock_valid = false;
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}
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}
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static int kvmclock_init(SysBusDevice *dev)
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{
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KVMClockState *s = FROM_SYSBUS(KVMClockState, dev);
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qemu_add_vm_change_state_handler(kvmclock_vm_state_change, s);
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return 0;
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}
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static const VMStateDescription kvmclock_vmsd = {
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.name = "kvmclock",
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.version_id = 1,
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.minimum_version_id = 1,
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.minimum_version_id_old = 1,
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.pre_save = kvmclock_pre_save,
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.post_load = kvmclock_post_load,
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.fields = (VMStateField[]) {
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VMSTATE_UINT64(clock, KVMClockState),
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VMSTATE_END_OF_LIST()
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}
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};
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static SysBusDeviceInfo kvmclock_info = {
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.qdev.name = "kvmclock",
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.qdev.size = sizeof(KVMClockState),
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.qdev.vmsd = &kvmclock_vmsd,
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.qdev.no_user = 1,
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.init = kvmclock_init,
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};
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/* Note: Must be called after VCPU initialization. */
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void kvmclock_create(void)
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{
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if (kvm_enabled() &&
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first_cpu->cpuid_kvm_features & ((1ULL << KVM_FEATURE_CLOCKSOURCE) |
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(1ULL << KVM_FEATURE_CLOCKSOURCE2))) {
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sysbus_create_simple("kvmclock", -1, NULL);
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}
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}
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static void kvmclock_register_device(void)
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{
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if (kvm_enabled()) {
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sysbus_register_withprop(&kvmclock_info);
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}
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}
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device_init(kvmclock_register_device);
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