--- /dev/null
+/*
+ * KVM in-kernel PIT (i8254) support
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2012 Jan Kiszka, Siemens AG
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu/timer.h"
+#include "sysemu/sysemu.h"
+#include "hw/timer/i8254.h"
+#include "hw/timer/i8254_internal.h"
+#include "sysemu/kvm.h"
+
+#define KVM_PIT_REINJECT_BIT 0
+
+#define CALIBRATION_ROUNDS 3
+
+#define KVM_PIT(obj) OBJECT_CHECK(KVMPITState, (obj), TYPE_KVM_I8254)
+#define KVM_PIT_CLASS(class) \
+ OBJECT_CLASS_CHECK(KVMPITClass, (class), TYPE_KVM_I8254)
+#define KVM_PIT_GET_CLASS(obj) \
+ OBJECT_GET_CLASS(KVMPITClass, (obj), TYPE_KVM_I8254)
+
+typedef struct KVMPITState {
+ PITCommonState parent_obj;
+
+ LostTickPolicy lost_tick_policy;
+ bool vm_stopped;
+ int64_t kernel_clock_offset;
+} KVMPITState;
+
+typedef struct KVMPITClass {
+ PITCommonClass parent_class;
+
+ DeviceRealize parent_realize;
+} KVMPITClass;
+
+static int64_t abs64(int64_t v)
+{
+ return v < 0 ? -v : v;
+}
+
+static void kvm_pit_update_clock_offset(KVMPITState *s)
+{
+ int64_t offset, clock_offset;
+ struct timespec ts;
+ int i;
+
+ /*
+ * Measure the delta between CLOCK_MONOTONIC, the base used for
+ * kvm_pit_channel_state::count_load_time, and QEMU_CLOCK_VIRTUAL. Take the
+ * minimum of several samples to filter out scheduling noise.
+ */
+ clock_offset = INT64_MAX;
+ for (i = 0; i < CALIBRATION_ROUNDS; i++) {
+ offset = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ clock_gettime(CLOCK_MONOTONIC, &ts);
+ offset -= ts.tv_nsec;
+ offset -= (int64_t)ts.tv_sec * 1000000000;
+ if (abs64(offset) < abs64(clock_offset)) {
+ clock_offset = offset;
+ }
+ }
+ s->kernel_clock_offset = clock_offset;
+}
+
+static void kvm_pit_get(PITCommonState *pit)
+{
+ KVMPITState *s = KVM_PIT(pit);
+ struct kvm_pit_state2 kpit;
+ struct kvm_pit_channel_state *kchan;
+ struct PITChannelState *sc;
+ int i, ret;
+
+ /* No need to re-read the state if VM is stopped. */
+ if (s->vm_stopped) {
+ return;
+ }
+
+ if (kvm_has_pit_state2()) {
+ ret = kvm_vm_ioctl(kvm_state, KVM_GET_PIT2, &kpit);
+ if (ret < 0) {
+ fprintf(stderr, "KVM_GET_PIT2 failed: %s\n", strerror(ret));
+ abort();
+ }
+ pit->channels[0].irq_disabled = kpit.flags & KVM_PIT_FLAGS_HPET_LEGACY;
+ } else {
+ /*
+ * kvm_pit_state2 is superset of kvm_pit_state struct,
+ * so we can use it for KVM_GET_PIT as well.
+ */
+ ret = kvm_vm_ioctl(kvm_state, KVM_GET_PIT, &kpit);
+ if (ret < 0) {
+ fprintf(stderr, "KVM_GET_PIT failed: %s\n", strerror(ret));
+ abort();
+ }
+ }
+ for (i = 0; i < 3; i++) {
+ kchan = &kpit.channels[i];
+ sc = &pit->channels[i];
+ sc->count = kchan->count;
+ sc->latched_count = kchan->latched_count;
+ sc->count_latched = kchan->count_latched;
+ sc->status_latched = kchan->status_latched;
+ sc->status = kchan->status;
+ sc->read_state = kchan->read_state;
+ sc->write_state = kchan->write_state;
+ sc->write_latch = kchan->write_latch;
+ sc->rw_mode = kchan->rw_mode;
+ sc->mode = kchan->mode;
+ sc->bcd = kchan->bcd;
+ sc->gate = kchan->gate;
+ sc->count_load_time = kchan->count_load_time + s->kernel_clock_offset;
+ }
+
+ sc = &pit->channels[0];
+ sc->next_transition_time =
+ pit_get_next_transition_time(sc, sc->count_load_time);
+}
+
+static void kvm_pit_put(PITCommonState *pit)
+{
+ KVMPITState *s = KVM_PIT(pit);
+ struct kvm_pit_state2 kpit = {};
+ struct kvm_pit_channel_state *kchan;
+ struct PITChannelState *sc;
+ int i, ret;
+
+ /* The offset keeps changing as long as the VM is stopped. */
+ if (s->vm_stopped) {
+ kvm_pit_update_clock_offset(s);
+ }
+
+ kpit.flags = pit->channels[0].irq_disabled ? KVM_PIT_FLAGS_HPET_LEGACY : 0;
+ for (i = 0; i < 3; i++) {
+ kchan = &kpit.channels[i];
+ sc = &pit->channels[i];
+ kchan->count = sc->count;
+ kchan->latched_count = sc->latched_count;
+ kchan->count_latched = sc->count_latched;
+ kchan->status_latched = sc->status_latched;
+ kchan->status = sc->status;
+ kchan->read_state = sc->read_state;
+ kchan->write_state = sc->write_state;
+ kchan->write_latch = sc->write_latch;
+ kchan->rw_mode = sc->rw_mode;
+ kchan->mode = sc->mode;
+ kchan->bcd = sc->bcd;
+ kchan->gate = sc->gate;
+ kchan->count_load_time = sc->count_load_time - s->kernel_clock_offset;
+ }
+
+ ret = kvm_vm_ioctl(kvm_state,
+ kvm_has_pit_state2() ? KVM_SET_PIT2 : KVM_SET_PIT,
+ &kpit);
+ if (ret < 0) {
+ fprintf(stderr, "%s failed: %s\n",
+ kvm_has_pit_state2() ? "KVM_SET_PIT2" : "KVM_SET_PIT",
+ strerror(ret));
+ abort();
+ }
+}
+
+static void kvm_pit_set_gate(PITCommonState *s, PITChannelState *sc, int val)
+{
+ kvm_pit_get(s);
+
+ switch (sc->mode) {
+ default:
+ case 0:
+ case 4:
+ /* XXX: just disable/enable counting */
+ break;
+ case 1:
+ case 2:
+ case 3:
+ case 5:
+ if (sc->gate < val) {
+ /* restart counting on rising edge */
+ sc->count_load_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ }
+ break;
+ }
+ sc->gate = val;
+
+ kvm_pit_put(s);
+}
+
+static void kvm_pit_get_channel_info(PITCommonState *s, PITChannelState *sc,
+ PITChannelInfo *info)
+{
+ kvm_pit_get(s);
+
+ pit_get_channel_info_common(s, sc, info);
+}
+
+static void kvm_pit_reset(DeviceState *dev)
+{
+ PITCommonState *s = PIT_COMMON(dev);
+
+ pit_reset_common(s);
+
+ kvm_pit_put(s);
+}
+
+static void kvm_pit_irq_control(void *opaque, int n, int enable)
+{
+ PITCommonState *pit = opaque;
+ PITChannelState *s = &pit->channels[0];
+
+ kvm_pit_get(pit);
+
+ s->irq_disabled = !enable;
+
+ kvm_pit_put(pit);
+}
+
+static void kvm_pit_vm_state_change(void *opaque, int running,
+ RunState state)
+{
+ KVMPITState *s = opaque;
+
+ if (running) {
+ kvm_pit_update_clock_offset(s);
+ kvm_pit_put(PIT_COMMON(s));
+ s->vm_stopped = false;
+ } else {
+ kvm_pit_update_clock_offset(s);
+ kvm_pit_get(PIT_COMMON(s));
+ s->vm_stopped = true;
+ }
+}
+
+static void kvm_pit_realizefn(DeviceState *dev, Error **errp)
+{
+ PITCommonState *pit = PIT_COMMON(dev);
+ KVMPITClass *kpc = KVM_PIT_GET_CLASS(dev);
+ KVMPITState *s = KVM_PIT(pit);
+ struct kvm_pit_config config = {
+ .flags = 0,
+ };
+ int ret;
+
+ if (kvm_check_extension(kvm_state, KVM_CAP_PIT2)) {
+ ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_PIT2, &config);
+ } else {
+ ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_PIT);
+ }
+ if (ret < 0) {
+ error_setg(errp, "Create kernel PIC irqchip failed: %s",
+ strerror(ret));
+ return;
+ }
+ switch (s->lost_tick_policy) {
+ case LOST_TICK_POLICY_DELAY:
+ break; /* enabled by default */
+ case LOST_TICK_POLICY_DISCARD:
+ if (kvm_check_extension(kvm_state, KVM_CAP_REINJECT_CONTROL)) {
+ struct kvm_reinject_control control = { .pit_reinject = 0 };
+
+ ret = kvm_vm_ioctl(kvm_state, KVM_REINJECT_CONTROL, &control);
+ if (ret < 0) {
+ error_setg(errp,
+ "Can't disable in-kernel PIT reinjection: %s",
+ strerror(ret));
+ return;
+ }
+ }
+ break;
+ default:
+ error_setg(errp, "Lost tick policy not supported.");
+ return;
+ }
+
+ memory_region_init_reservation(&pit->ioports, NULL, "kvm-pit", 4);
+
+ qdev_init_gpio_in(dev, kvm_pit_irq_control, 1);
+
+ qemu_add_vm_change_state_handler(kvm_pit_vm_state_change, s);
+
+ kpc->parent_realize(dev, errp);
+}
+
+static Property kvm_pit_properties[] = {
+ DEFINE_PROP_UINT32("iobase", PITCommonState, iobase, -1),
+ DEFINE_PROP_LOSTTICKPOLICY("lost_tick_policy", KVMPITState,
+ lost_tick_policy, LOST_TICK_POLICY_DELAY),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void kvm_pit_class_init(ObjectClass *klass, void *data)
+{
+ KVMPITClass *kpc = KVM_PIT_CLASS(klass);
+ PITCommonClass *k = PIT_COMMON_CLASS(klass);
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ kpc->parent_realize = dc->realize;
+ dc->realize = kvm_pit_realizefn;
+ k->set_channel_gate = kvm_pit_set_gate;
+ k->get_channel_info = kvm_pit_get_channel_info;
+ dc->reset = kvm_pit_reset;
+ dc->props = kvm_pit_properties;
+}
+
+static const TypeInfo kvm_pit_info = {
+ .name = TYPE_KVM_I8254,
+ .parent = TYPE_PIT_COMMON,
+ .instance_size = sizeof(KVMPITState),
+ .class_init = kvm_pit_class_init,
+ .class_size = sizeof(KVMPITClass),
+};
+
+static void kvm_pit_register(void)
+{
+ type_register_static(&kvm_pit_info);
+}
+
+type_init(kvm_pit_register)
Code Review / kvmfornfv.git / blobdiff