diff options
Diffstat (limited to 'hw/i386/kvm/i8254.c')
| -rw-r--r-- | hw/i386/kvm/i8254.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/hw/i386/kvm/i8254.c b/hw/i386/kvm/i8254.c new file mode 100644 index 0000000000..da90711853 --- /dev/null +++ b/hw/i386/kvm/i8254.c @@ -0,0 +1,317 @@ +/* + * 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 + +typedef struct KVMPITState { + PITCommonState pit; + LostTickPolicy lost_tick_policy; + bool vm_stopped; + int64_t kernel_clock_offset; +} KVMPITState; + +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 vm_clock. Take the + * minimum of several samples to filter out scheduling noise. + */ + clock_offset = INT64_MAX; + for (i = 0; i < CALIBRATION_ROUNDS; i++) { + offset = qemu_get_clock_ns(vm_clock); + 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 = DO_UPCAST(KVMPITState, 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 = DO_UPCAST(KVMPITState, 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_get_clock_ns(vm_clock); + } + 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 = DO_UPCAST(PITCommonState, dev.qdev, 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); + s->vm_stopped = false; + } else { + kvm_pit_update_clock_offset(s); + kvm_pit_get(&s->pit); + s->vm_stopped = true; + } +} + +static int kvm_pit_initfn(PITCommonState *pit) +{ + KVMPITState *s = DO_UPCAST(KVMPITState, 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) { + fprintf(stderr, "Create kernel PIC irqchip failed: %s\n", + strerror(ret)); + return ret; + } + switch (s->lost_tick_policy) { + case LOST_TICK_DELAY: + break; /* enabled by default */ + case LOST_TICK_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) { + fprintf(stderr, + "Can't disable in-kernel PIT reinjection: %s\n", + strerror(ret)); + return ret; + } + } + break; + default: + return -EINVAL; + } + + memory_region_init_reservation(&pit->ioports, "kvm-pit", 4); + + qdev_init_gpio_in(&pit->dev.qdev, kvm_pit_irq_control, 1); + + qemu_add_vm_change_state_handler(kvm_pit_vm_state_change, s); + + return 0; +} + +static Property kvm_pit_properties[] = { + DEFINE_PROP_HEX32("iobase", KVMPITState, pit.iobase, -1), + DEFINE_PROP_LOSTTICKPOLICY("lost_tick_policy", KVMPITState, + lost_tick_policy, LOST_TICK_DELAY), + DEFINE_PROP_END_OF_LIST(), +}; + +static void kvm_pit_class_init(ObjectClass *klass, void *data) +{ + PITCommonClass *k = PIT_COMMON_CLASS(klass); + DeviceClass *dc = DEVICE_CLASS(klass); + + k->init = kvm_pit_initfn; + k->set_channel_gate = kvm_pit_set_gate; + k->get_channel_info = kvm_pit_get_channel_info; + k->pre_save = kvm_pit_get; + k->post_load = kvm_pit_put; + dc->reset = kvm_pit_reset; + dc->props = kvm_pit_properties; +} + +static const TypeInfo kvm_pit_info = { + .name = "kvm-pit", + .parent = TYPE_PIT_COMMON, + .instance_size = sizeof(KVMPITState), + .class_init = kvm_pit_class_init, +}; + +static void kvm_pit_register(void) +{ + type_register_static(&kvm_pit_info); +} + +type_init(kvm_pit_register) |