[mirror_qemu.git] / hw / kvm / i8254.c

/*
 * 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.h"
#include "hw/i8254.h"
#include "hw/i8254_internal.h"
#include "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 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)
Commit	Line	Data
5d17c0d2 JK	1	/*
	2	* KVM in-kernel PIT (i8254) support
	3	*
	4	* Copyright (c) 2003-2004 Fabrice Bellard
	5	* Copyright (c) 2012 Jan Kiszka, Siemens AG
	6	*
	7	* Permission is hereby granted, free of charge, to any person obtaining a copy
	8	* of this software and associated documentation files (the "Software"), to deal
	9	* in the Software without restriction, including without limitation the rights
	10	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	11	* copies of the Software, and to permit persons to whom the Software is
	12	* furnished to do so, subject to the following conditions:
	13	*
	14	* The above copyright notice and this permission notice shall be included in
	15	* all copies or substantial portions of the Software.
	16	*
	17	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	18	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	19	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	20	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	21	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	22	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	23	* THE SOFTWARE.
	24	*/
1de7afc9	25	#include "qemu/timer.h"
0cdd3d14	26	#include "sysemu.h"
5d17c0d2 JK	27	#include "hw/i8254.h"
	28	#include "hw/i8254_internal.h"
	29	#include "kvm.h"
	30
	31	#define KVM_PIT_REINJECT_BIT 0
	32
0cdd3d14 JK	33	#define CALIBRATION_ROUNDS 3
0cdd3d14 JK	34
5d17c0d2 JK	35	typedef struct KVMPITState {
	36	PITCommonState pit;
	37	LostTickPolicy lost_tick_policy;
205df4d1 JK	38	bool vm_stopped;
205df4d1 JK	39	int64_t kernel_clock_offset;
5d17c0d2 JK	40	} KVMPITState;
5d17c0d2 JK	41
0cdd3d14	42	static int64_t abs64(int64_t v)
5d17c0d2	43	{
0cdd3d14 JK	44	return v < 0 ? -v : v;
	45	}
	46
205df4d1	47	static void kvm_pit_update_clock_offset(KVMPITState *s)
0cdd3d14	48	{
0cdd3d14 JK	49	int64_t offset, clock_offset;
0cdd3d14 JK	50	struct timespec ts;
205df4d1	51	int i;
0cdd3d14 JK	52
	53	/*
	54	* Measure the delta between CLOCK_MONOTONIC, the base used for
	55	* kvm_pit_channel_state::count_load_time, and vm_clock. Take the
	56	* minimum of several samples to filter out scheduling noise.
	57	*/
	58	clock_offset = INT64_MAX;
	59	for (i = 0; i < CALIBRATION_ROUNDS; i++) {
	60	offset = qemu_get_clock_ns(vm_clock);
	61	clock_gettime(CLOCK_MONOTONIC, &ts);
	62	offset -= ts.tv_nsec;
	63	offset -= (int64_t)ts.tv_sec * 1000000000;
	64	if (abs64(offset) < abs64(clock_offset)) {
	65	clock_offset = offset;
	66	}
	67	}
205df4d1 JK	68	s->kernel_clock_offset = clock_offset;
	69	}
	70
	71	static void kvm_pit_get(PITCommonState *pit)
	72	{
	73	KVMPITState *s = DO_UPCAST(KVMPITState, pit, pit);
	74	struct kvm_pit_state2 kpit;
	75	struct kvm_pit_channel_state *kchan;
	76	struct PITChannelState *sc;
	77	int i, ret;
	78
	79	/* No need to re-read the state if VM is stopped. */
	80	if (s->vm_stopped) {
	81	return;
	82	}
0cdd3d14	83
5d17c0d2 JK	84	if (kvm_has_pit_state2()) {
	85	ret = kvm_vm_ioctl(kvm_state, KVM_GET_PIT2, &kpit);
	86	if (ret < 0) {
	87	fprintf(stderr, "KVM_GET_PIT2 failed: %s\n", strerror(ret));
	88	abort();
	89	}
0cdd3d14	90	pit->channels[0].irq_disabled = kpit.flags & KVM_PIT_FLAGS_HPET_LEGACY;
5d17c0d2 JK	91	} else {
	92	/*
	93	* kvm_pit_state2 is superset of kvm_pit_state struct,
	94	* so we can use it for KVM_GET_PIT as well.
	95	*/
	96	ret = kvm_vm_ioctl(kvm_state, KVM_GET_PIT, &kpit);
	97	if (ret < 0) {
	98	fprintf(stderr, "KVM_GET_PIT failed: %s\n", strerror(ret));
	99	abort();
	100	}
	101	}
	102	for (i = 0; i < 3; i++) {
	103	kchan = &kpit.channels[i];
0cdd3d14	104	sc = &pit->channels[i];
5d17c0d2 JK	105	sc->count = kchan->count;
	106	sc->latched_count = kchan->latched_count;
	107	sc->count_latched = kchan->count_latched;
	108	sc->status_latched = kchan->status_latched;
	109	sc->status = kchan->status;
	110	sc->read_state = kchan->read_state;
	111	sc->write_state = kchan->write_state;
	112	sc->write_latch = kchan->write_latch;
	113	sc->rw_mode = kchan->rw_mode;
	114	sc->mode = kchan->mode;
	115	sc->bcd = kchan->bcd;
	116	sc->gate = kchan->gate;
205df4d1	117	sc->count_load_time = kchan->count_load_time + s->kernel_clock_offset;
5d17c0d2 JK	118	}
5d17c0d2 JK	119
0cdd3d14	120	sc = &pit->channels[0];
5d17c0d2 JK	121	sc->next_transition_time =
	122	pit_get_next_transition_time(sc, sc->count_load_time);
	123	}
	124
050a4606	125	static void kvm_pit_put(PITCommonState *pit)
5d17c0d2	126	{
050a4606	127	KVMPITState *s = DO_UPCAST(KVMPITState, pit, pit);
5d17c0d2 JK	128	struct kvm_pit_state2 kpit;
	129	struct kvm_pit_channel_state *kchan;
	130	struct PITChannelState *sc;
	131	int i, ret;
	132
050a4606 JK	133	/* The offset keeps changing as long as the VM is stopped. */
	134	if (s->vm_stopped) {
	135	kvm_pit_update_clock_offset(s);
	136	}
	137
	138	kpit.flags = pit->channels[0].irq_disabled ? KVM_PIT_FLAGS_HPET_LEGACY : 0;
5d17c0d2 JK	139	for (i = 0; i < 3; i++) {
5d17c0d2 JK	140	kchan = &kpit.channels[i];
050a4606	141	sc = &pit->channels[i];
5d17c0d2 JK	142	kchan->count = sc->count;
	143	kchan->latched_count = sc->latched_count;
	144	kchan->count_latched = sc->count_latched;
	145	kchan->status_latched = sc->status_latched;
	146	kchan->status = sc->status;
	147	kchan->read_state = sc->read_state;
	148	kchan->write_state = sc->write_state;
	149	kchan->write_latch = sc->write_latch;
	150	kchan->rw_mode = sc->rw_mode;
	151	kchan->mode = sc->mode;
	152	kchan->bcd = sc->bcd;
	153	kchan->gate = sc->gate;
050a4606	154	kchan->count_load_time = sc->count_load_time - s->kernel_clock_offset;
5d17c0d2 JK	155	}
	156
	157	ret = kvm_vm_ioctl(kvm_state,
	158	kvm_has_pit_state2() ? KVM_SET_PIT2 : KVM_SET_PIT,
	159	&kpit);
	160	if (ret < 0) {
	161	fprintf(stderr, "%s failed: %s\n",
	162	kvm_has_pit_state2() ? "KVM_SET_PIT2" : "KVM_SET_PIT",
	163	strerror(ret));
	164	abort();
	165	}
	166	}
	167
	168	static void kvm_pit_set_gate(PITCommonState s, PITChannelState sc, int val)
	169	{
	170	kvm_pit_get(s);
	171
	172	switch (sc->mode) {
	173	default:
	174	case 0:
	175	case 4:
	176	/* XXX: just disable/enable counting */
	177	break;
	178	case 1:
	179	case 2:
	180	case 3:
	181	case 5:
	182	if (sc->gate < val) {
	183	/* restart counting on rising edge */
	184	sc->count_load_time = qemu_get_clock_ns(vm_clock);
	185	}
	186	break;
	187	}
	188	sc->gate = val;
	189
	190	kvm_pit_put(s);
	191	}
	192
	193	static void kvm_pit_get_channel_info(PITCommonState s, PITChannelState sc,
	194	PITChannelInfo *info)
	195	{
	196	kvm_pit_get(s);
	197
	198	pit_get_channel_info_common(s, sc, info);
	199	}
	200
	201	static void kvm_pit_reset(DeviceState *dev)
	202	{
	203	PITCommonState *s = DO_UPCAST(PITCommonState, dev.qdev, dev);
	204
	205	pit_reset_common(s);
	206
	207	kvm_pit_put(s);
	208	}
	209
	210	static void kvm_pit_irq_control(void *opaque, int n, int enable)
	211	{
	212	PITCommonState *pit = opaque;
	213	PITChannelState *s = &pit->channels[0];
	214
	215	kvm_pit_get(pit);
	216
	217	s->irq_disabled = !enable;
	218
219	kvm_pit_put(pit);
220	}
221
0cdd3d14 JK	222	static void kvm_pit_vm_state_change(void *opaque, int running,
	223	RunState state)
	224	{
	225	KVMPITState *s = opaque;
	226
	227	if (running) {
205df4d1 JK	228	kvm_pit_update_clock_offset(s);
205df4d1 JK	229	s->vm_stopped = false;
0cdd3d14	230	} else {
205df4d1	231	kvm_pit_update_clock_offset(s);
0cdd3d14	232	kvm_pit_get(&s->pit);
205df4d1	233	s->vm_stopped = true;
0cdd3d14 JK	234	}
	235	}
	236
5d17c0d2 JK	237	static int kvm_pit_initfn(PITCommonState *pit)
	238	{
	239	KVMPITState *s = DO_UPCAST(KVMPITState, pit, pit);
	240	struct kvm_pit_config config = {
	241	.flags = 0,
	242	};
	243	int ret;
	244
	245	if (kvm_check_extension(kvm_state, KVM_CAP_PIT2)) {
	246	ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_PIT2, &config);
	247	} else {
	248	ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_PIT);
	249	}
	250	if (ret < 0) {
	251	fprintf(stderr, "Create kernel PIC irqchip failed: %s\n",
	252	strerror(ret));
	253	return ret;
	254	}
	255	switch (s->lost_tick_policy) {
	256	case LOST_TICK_DELAY:
	257	break; /* enabled by default */
	258	case LOST_TICK_DISCARD:
	259	if (kvm_check_extension(kvm_state, KVM_CAP_REINJECT_CONTROL)) {
	260	struct kvm_reinject_control control = { .pit_reinject = 0 };
	261
	262	ret = kvm_vm_ioctl(kvm_state, KVM_REINJECT_CONTROL, &control);
	263	if (ret < 0) {
	264	fprintf(stderr,
	265	"Can't disable in-kernel PIT reinjection: %s\n",
	266	strerror(ret));
	267	return ret;
	268	}
	269	}
	270	break;
	271	default:
	272	return -EINVAL;
	273	}
	274
	275	memory_region_init_reservation(&pit->ioports, "kvm-pit", 4);
	276
	277	qdev_init_gpio_in(&pit->dev.qdev, kvm_pit_irq_control, 1);
	278
0cdd3d14 JK	279	qemu_add_vm_change_state_handler(kvm_pit_vm_state_change, s);
0cdd3d14 JK	280
5d17c0d2 JK	281	return 0;
	282	}
	283
	284	static Property kvm_pit_properties[] = {
	285	DEFINE_PROP_HEX32("iobase", KVMPITState, pit.iobase, -1),
	286	DEFINE_PROP_LOSTTICKPOLICY("lost_tick_policy", KVMPITState,
	287	lost_tick_policy, LOST_TICK_DELAY),
	288	DEFINE_PROP_END_OF_LIST(),
	289	};
	290
	291	static void kvm_pit_class_init(ObjectClass klass, void data)
	292	{
	293	PITCommonClass *k = PIT_COMMON_CLASS(klass);
	294	DeviceClass *dc = DEVICE_CLASS(klass);
	295
	296	k->init = kvm_pit_initfn;
	297	k->set_channel_gate = kvm_pit_set_gate;
	298	k->get_channel_info = kvm_pit_get_channel_info;
	299	k->pre_save = kvm_pit_get;
	300	k->post_load = kvm_pit_put;
	301	dc->reset = kvm_pit_reset;
	302	dc->props = kvm_pit_properties;
	303	}
	304
	305	static TypeInfo kvm_pit_info = {
	306	.name = "kvm-pit",
	307	.parent = TYPE_PIT_COMMON,
	308	.instance_size = sizeof(KVMPITState),
	309	.class_init = kvm_pit_class_init,
	310	};
	311
	312	static void kvm_pit_register(void)
	313	{
	314	type_register_static(&kvm_pit_info);
	315	}
	316
	317	type_init(kvm_pit_register)