[qemu.git] / hw / virtio / virtio-mmio.c

/*
 * Virtio MMIO bindings
 *
 * Copyright (c) 2011 Linaro Limited
 *
 * Author:
 *  Peter Maydell <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "hw/sysbus.h"
#include "hw/virtio/virtio.h"
#include "qemu/host-utils.h"
#include "sysemu/kvm.h"
#include "hw/virtio/virtio-bus.h"
#include "qemu/error-report.h"

/* #define DEBUG_VIRTIO_MMIO */

#ifdef DEBUG_VIRTIO_MMIO

#define DPRINTF(fmt, ...) \
do { printf("virtio_mmio: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) do {} while (0)
#endif

/* QOM macros */
/* virtio-mmio-bus */
#define TYPE_VIRTIO_MMIO_BUS "virtio-mmio-bus"
#define VIRTIO_MMIO_BUS(obj) \
        OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_MMIO_BUS)
#define VIRTIO_MMIO_BUS_GET_CLASS(obj) \
        OBJECT_GET_CLASS(VirtioBusClass, (obj), TYPE_VIRTIO_MMIO_BUS)
#define VIRTIO_MMIO_BUS_CLASS(klass) \
        OBJECT_CLASS_CHECK(VirtioBusClass, (klass), TYPE_VIRTIO_MMIO_BUS)

/* virtio-mmio */
#define TYPE_VIRTIO_MMIO "virtio-mmio"
#define VIRTIO_MMIO(obj) \
        OBJECT_CHECK(VirtIOMMIOProxy, (obj), TYPE_VIRTIO_MMIO)

/* Memory mapped register offsets */
#define VIRTIO_MMIO_MAGIC 0x0
#define VIRTIO_MMIO_VERSION 0x4
#define VIRTIO_MMIO_DEVICEID 0x8
#define VIRTIO_MMIO_VENDORID 0xc
#define VIRTIO_MMIO_HOSTFEATURES 0x10
#define VIRTIO_MMIO_HOSTFEATURESSEL 0x14
#define VIRTIO_MMIO_GUESTFEATURES 0x20
#define VIRTIO_MMIO_GUESTFEATURESSEL 0x24
#define VIRTIO_MMIO_GUESTPAGESIZE 0x28
#define VIRTIO_MMIO_QUEUESEL 0x30
#define VIRTIO_MMIO_QUEUENUMMAX 0x34
#define VIRTIO_MMIO_QUEUENUM 0x38
#define VIRTIO_MMIO_QUEUEALIGN 0x3c
#define VIRTIO_MMIO_QUEUEPFN 0x40
#define VIRTIO_MMIO_QUEUENOTIFY 0x50
#define VIRTIO_MMIO_INTERRUPTSTATUS 0x60
#define VIRTIO_MMIO_INTERRUPTACK 0x64
#define VIRTIO_MMIO_STATUS 0x70
/* Device specific config space starts here */
#define VIRTIO_MMIO_CONFIG 0x100

#define VIRT_MAGIC 0x74726976 /* 'virt' */
#define VIRT_VERSION 1
#define VIRT_VENDOR 0x554D4551 /* 'QEMU' */

typedef struct {
    /* Generic */
    SysBusDevice parent_obj;
    MemoryRegion iomem;
    qemu_irq irq;
    /* Guest accessible state needing migration and reset */
    uint32_t host_features_sel;
    uint32_t guest_features_sel;
    uint32_t guest_page_shift;
    /* virtio-bus */
    VirtioBusState bus;
    bool ioeventfd_disabled;
    bool ioeventfd_started;
} VirtIOMMIOProxy;

static int virtio_mmio_set_host_notifier_internal(VirtIOMMIOProxy *proxy,
                                                  int n, bool assign,
                                                  bool set_handler)
{
    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
    VirtQueue *vq = virtio_get_queue(vdev, n);
    EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
    int r = 0;

    if (assign) {
        r = event_notifier_init(notifier, 1);
        if (r < 0) {
            error_report("%s: unable to init event notifier: %d",
                         __func__, r);
            return r;
        }
        virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler);
        memory_region_add_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
                                  true, n, notifier);
    } else {
        memory_region_del_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
                                  true, n, notifier);
        virtio_queue_set_host_notifier_fd_handler(vq, false, false);
        event_notifier_cleanup(notifier);
    }
    return r;
}

static void virtio_mmio_start_ioeventfd(VirtIOMMIOProxy *proxy)
{
    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
    int n, r;

    if (!kvm_eventfds_enabled() ||
        proxy->ioeventfd_disabled ||
        proxy->ioeventfd_started) {
        return;
    }

    for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
        if (!virtio_queue_get_num(vdev, n)) {
            continue;
        }

        r = virtio_mmio_set_host_notifier_internal(proxy, n, true, true);
        if (r < 0) {
            goto assign_error;
        }
    }
    proxy->ioeventfd_started = true;
    return;

assign_error:
    while (--n >= 0) {
        if (!virtio_queue_get_num(vdev, n)) {
            continue;
        }

        r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false);
        assert(r >= 0);
    }
    proxy->ioeventfd_started = false;
    error_report("%s: failed. Fallback to a userspace (slower).", __func__);
}

static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy)
{
    int r;
    int n;
    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);

    if (!proxy->ioeventfd_started) {
        return;
    }

    for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
        if (!virtio_queue_get_num(vdev, n)) {
            continue;
        }

        r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false);
        assert(r >= 0);
    }
    proxy->ioeventfd_started = false;
}

static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
{
    VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);

    DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);

    if (!vdev) {
        /* If no backend is present, we treat most registers as
         * read-as-zero, except for the magic number, version and
         * vendor ID. This is not strictly sanctioned by the virtio
         * spec, but it allows us to provide transports with no backend
         * plugged in which don't confuse Linux's virtio code: the
         * probe won't complain about the bad magic number, but the
         * device ID of zero means no backend will claim it.
         */
        switch (offset) {
        case VIRTIO_MMIO_MAGIC:
            return VIRT_MAGIC;
        case VIRTIO_MMIO_VERSION:
            return VIRT_VERSION;
        case VIRTIO_MMIO_VENDORID:
            return VIRT_VENDOR;
        default:
            return 0;
        }
    }

    if (offset >= VIRTIO_MMIO_CONFIG) {
        offset -= VIRTIO_MMIO_CONFIG;
        switch (size) {
        case 1:
            return virtio_config_readb(vdev, offset);
        case 2:
            return virtio_config_readw(vdev, offset);
        case 4:
            return virtio_config_readl(vdev, offset);
        default:
            abort();
        }
    }
    if (size != 4) {
        DPRINTF("wrong size access to register!\n");
        return 0;
    }
    switch (offset) {
    case VIRTIO_MMIO_MAGIC:
        return VIRT_MAGIC;
    case VIRTIO_MMIO_VERSION:
        return VIRT_VERSION;
    case VIRTIO_MMIO_DEVICEID:
        return vdev->device_id;
    case VIRTIO_MMIO_VENDORID:
        return VIRT_VENDOR;
    case VIRTIO_MMIO_HOSTFEATURES:
        if (proxy->host_features_sel) {
            return 0;
        }
        return vdev->host_features;
    case VIRTIO_MMIO_QUEUENUMMAX:
        if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
            return 0;
        }
        return VIRTQUEUE_MAX_SIZE;
    case VIRTIO_MMIO_QUEUEPFN:
        return virtio_queue_get_addr(vdev, vdev->queue_sel)
            >> proxy->guest_page_shift;
    case VIRTIO_MMIO_INTERRUPTSTATUS:
        return vdev->isr;
    case VIRTIO_MMIO_STATUS:
        return vdev->status;
    case VIRTIO_MMIO_HOSTFEATURESSEL:
    case VIRTIO_MMIO_GUESTFEATURES:
    case VIRTIO_MMIO_GUESTFEATURESSEL:
    case VIRTIO_MMIO_GUESTPAGESIZE:
    case VIRTIO_MMIO_QUEUESEL:
    case VIRTIO_MMIO_QUEUENUM:
    case VIRTIO_MMIO_QUEUEALIGN:
    case VIRTIO_MMIO_QUEUENOTIFY:
    case VIRTIO_MMIO_INTERRUPTACK:
        DPRINTF("read of write-only register\n");
        return 0;
    default:
        DPRINTF("bad register offset\n");
        return 0;
    }
    return 0;
}

static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
                              unsigned size)
{
    VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);

    DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
            (int)offset, value);

    if (!vdev) {
        /* If no backend is present, we just make all registers
         * write-ignored. This allows us to provide transports with
         * no backend plugged in.
         */
        return;
    }

    if (offset >= VIRTIO_MMIO_CONFIG) {
        offset -= VIRTIO_MMIO_CONFIG;
        switch (size) {
        case 1:
            virtio_config_writeb(vdev, offset, value);
            break;
        case 2:
            virtio_config_writew(vdev, offset, value);
            break;
        case 4:
            virtio_config_writel(vdev, offset, value);
            break;
        default:
            abort();
        }
        return;
    }
    if (size != 4) {
        DPRINTF("wrong size access to register!\n");
        return;
    }
    switch (offset) {
    case VIRTIO_MMIO_HOSTFEATURESSEL:
        proxy->host_features_sel = value;
        break;
    case VIRTIO_MMIO_GUESTFEATURES:
        if (!proxy->guest_features_sel) {
            virtio_set_features(vdev, value);
        }
        break;
    case VIRTIO_MMIO_GUESTFEATURESSEL:
        proxy->guest_features_sel = value;
        break;
    case VIRTIO_MMIO_GUESTPAGESIZE:
        proxy->guest_page_shift = ctz32(value);
        if (proxy->guest_page_shift > 31) {
            proxy->guest_page_shift = 0;
        }
        DPRINTF("guest page size %" PRIx64 " shift %d\n", value,
                proxy->guest_page_shift);
        break;
    case VIRTIO_MMIO_QUEUESEL:
        if (value < VIRTIO_QUEUE_MAX) {
            vdev->queue_sel = value;
        }
        break;
    case VIRTIO_MMIO_QUEUENUM:
        DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE);
        virtio_queue_set_num(vdev, vdev->queue_sel, value);
        break;
    case VIRTIO_MMIO_QUEUEALIGN:
        virtio_queue_set_align(vdev, vdev->queue_sel, value);
        break;
    case VIRTIO_MMIO_QUEUEPFN:
        if (value == 0) {
            virtio_reset(vdev);
        } else {
            virtio_queue_set_addr(vdev, vdev->queue_sel,
                                  value << proxy->guest_page_shift);
        }
        break;
    case VIRTIO_MMIO_QUEUENOTIFY:
        if (value < VIRTIO_QUEUE_MAX) {
            virtio_queue_notify(vdev, value);
        }
        break;
    case VIRTIO_MMIO_INTERRUPTACK:
        vdev->isr &= ~value;
        virtio_update_irq(vdev);
        break;
    case VIRTIO_MMIO_STATUS:
        if (!(value & VIRTIO_CONFIG_S_DRIVER_OK)) {
            virtio_mmio_stop_ioeventfd(proxy);
        }

        virtio_set_status(vdev, value & 0xff);

        if (value & VIRTIO_CONFIG_S_DRIVER_OK) {
            virtio_mmio_start_ioeventfd(proxy);
        }

        if (vdev->status == 0) {
            virtio_reset(vdev);
        }
        break;
    case VIRTIO_MMIO_MAGIC:
    case VIRTIO_MMIO_VERSION:
    case VIRTIO_MMIO_DEVICEID:
    case VIRTIO_MMIO_VENDORID:
    case VIRTIO_MMIO_HOSTFEATURES:
    case VIRTIO_MMIO_QUEUENUMMAX:
    case VIRTIO_MMIO_INTERRUPTSTATUS:
        DPRINTF("write to readonly register\n");
        break;

    default:
        DPRINTF("bad register offset\n");
    }
}

static const MemoryRegionOps virtio_mem_ops = {
    .read = virtio_mmio_read,
    .write = virtio_mmio_write,
    .endianness = DEVICE_NATIVE_ENDIAN,
};

static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
    int level;

    if (!vdev) {
        return;
    }
    level = (vdev->isr != 0);
    DPRINTF("virtio_mmio setting IRQ %d\n", level);
    qemu_set_irq(proxy->irq, level);
}

static int virtio_mmio_load_config(DeviceState *opaque, QEMUFile *f)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);

    proxy->host_features_sel = qemu_get_be32(f);
    proxy->guest_features_sel = qemu_get_be32(f);
    proxy->guest_page_shift = qemu_get_be32(f);
    return 0;
}

static void virtio_mmio_save_config(DeviceState *opaque, QEMUFile *f)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);

    qemu_put_be32(f, proxy->host_features_sel);
    qemu_put_be32(f, proxy->guest_features_sel);
    qemu_put_be32(f, proxy->guest_page_shift);
}

static void virtio_mmio_reset(DeviceState *d)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);

    virtio_mmio_stop_ioeventfd(proxy);
    virtio_bus_reset(&proxy->bus);
    proxy->host_features_sel = 0;
    proxy->guest_features_sel = 0;
    proxy->guest_page_shift = 0;
}

static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
                                          bool with_irqfd)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
    VirtQueue *vq = virtio_get_queue(vdev, n);
    EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);

    if (assign) {
        int r = event_notifier_init(notifier, 0);
        if (r < 0) {
            return r;
        }
        virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
    } else {
        virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
        event_notifier_cleanup(notifier);
    }

    if (vdc->guest_notifier_mask) {
        vdc->guest_notifier_mask(vdev, n, !assign);
    }

    return 0;
}

static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
                                           bool assign)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
    /* TODO: need to check if kvm-arm supports irqfd */
    bool with_irqfd = false;
    int r, n;

    nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);

    for (n = 0; n < nvqs; n++) {
        if (!virtio_queue_get_num(vdev, n)) {
            break;
        }

        r = virtio_mmio_set_guest_notifier(d, n, assign, with_irqfd);
        if (r < 0) {
            goto assign_error;
        }
    }

    return 0;

assign_error:
    /* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
    assert(assign);
    while (--n >= 0) {
        virtio_mmio_set_guest_notifier(d, n, !assign, false);
    }
    return r;
}

static int virtio_mmio_set_host_notifier(DeviceState *opaque, int n,
                                         bool assign)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);

    /* Stop using ioeventfd for virtqueue kick if the device starts using host
     * notifiers.  This makes it easy to avoid stepping on each others' toes.
     */
    proxy->ioeventfd_disabled = assign;
    if (assign) {
        virtio_mmio_stop_ioeventfd(proxy);
    }
    /* We don't need to start here: it's not needed because backend
     * currently only stops on status change away from ok,
     * reset, vmstop and such. If we do add code to start here,
     * need to check vmstate, device state etc. */
    return virtio_mmio_set_host_notifier_internal(proxy, n, assign, false);
}

/* virtio-mmio device */

static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
    SysBusDevice *sbd = SYS_BUS_DEVICE(d);

    qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS,
                        d, NULL);
    sysbus_init_irq(sbd, &proxy->irq);
    memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy,
                          TYPE_VIRTIO_MMIO, 0x200);
    sysbus_init_mmio(sbd, &proxy->iomem);
}

static void virtio_mmio_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);

    dc->realize = virtio_mmio_realizefn;
    dc->reset = virtio_mmio_reset;
    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
}

static const TypeInfo virtio_mmio_info = {
    .name          = TYPE_VIRTIO_MMIO,
    .parent        = TYPE_SYS_BUS_DEVICE,
    .instance_size = sizeof(VirtIOMMIOProxy),
    .class_init    = virtio_mmio_class_init,
};

/* virtio-mmio-bus. */

static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
{
    BusClass *bus_class = BUS_CLASS(klass);
    VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);

    k->notify = virtio_mmio_update_irq;
    k->save_config = virtio_mmio_save_config;
    k->load_config = virtio_mmio_load_config;
    k->set_host_notifier = virtio_mmio_set_host_notifier;
    k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
    k->has_variable_vring_alignment = true;
    bus_class->max_dev = 1;
}

static const TypeInfo virtio_mmio_bus_info = {
    .name          = TYPE_VIRTIO_MMIO_BUS,
    .parent        = TYPE_VIRTIO_BUS,
    .instance_size = sizeof(VirtioBusState),
    .class_init    = virtio_mmio_bus_class_init,
};

static void virtio_mmio_register_types(void)
{
    type_register_static(&virtio_mmio_bus_info);
    type_register_static(&virtio_mmio_info);
}

type_init(virtio_mmio_register_types)
Commit	Line	Data
4b52530b PM	1	/*
	2	* Virtio MMIO bindings
	3	*
	4	* Copyright (c) 2011 Linaro Limited
	5	*
	6	* Author:
	7	* Peter Maydell <[email protected]>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License; either version 2
	11	* of the License, or (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License along
	19	* with this program; if not, see <http://www.gnu.org/licenses/>.
	20	*/
	21
	22	#include "hw/sysbus.h"
	23	#include "hw/virtio/virtio.h"
	24	#include "qemu/host-utils.h"
434027ba	25	#include "sysemu/kvm.h"
4b52530b	26	#include "hw/virtio/virtio-bus.h"
434027ba	27	#include "qemu/error-report.h"
4b52530b PM	28
	29	/* #define DEBUG_VIRTIO_MMIO */
	30
	31	#ifdef DEBUG_VIRTIO_MMIO
	32
	33	#define DPRINTF(fmt, ...) \
	34	do { printf("virtio_mmio: " fmt , ## __VA_ARGS__); } while (0)
	35	#else
	36	#define DPRINTF(fmt, ...) do {} while (0)
	37	#endif
	38
	39	/* QOM macros */
	40	/* virtio-mmio-bus */
	41	#define TYPE_VIRTIO_MMIO_BUS "virtio-mmio-bus"
	42	#define VIRTIO_MMIO_BUS(obj) \
	43	OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_MMIO_BUS)
	44	#define VIRTIO_MMIO_BUS_GET_CLASS(obj) \
	45	OBJECT_GET_CLASS(VirtioBusClass, (obj), TYPE_VIRTIO_MMIO_BUS)
	46	#define VIRTIO_MMIO_BUS_CLASS(klass) \
	47	OBJECT_CLASS_CHECK(VirtioBusClass, (klass), TYPE_VIRTIO_MMIO_BUS)
	48
	49	/* virtio-mmio */
	50	#define TYPE_VIRTIO_MMIO "virtio-mmio"
	51	#define VIRTIO_MMIO(obj) \
	52	OBJECT_CHECK(VirtIOMMIOProxy, (obj), TYPE_VIRTIO_MMIO)
	53
	54	/* Memory mapped register offsets */
	55	#define VIRTIO_MMIO_MAGIC 0x0
	56	#define VIRTIO_MMIO_VERSION 0x4
	57	#define VIRTIO_MMIO_DEVICEID 0x8
	58	#define VIRTIO_MMIO_VENDORID 0xc
	59	#define VIRTIO_MMIO_HOSTFEATURES 0x10
	60	#define VIRTIO_MMIO_HOSTFEATURESSEL 0x14
	61	#define VIRTIO_MMIO_GUESTFEATURES 0x20
	62	#define VIRTIO_MMIO_GUESTFEATURESSEL 0x24
	63	#define VIRTIO_MMIO_GUESTPAGESIZE 0x28
	64	#define VIRTIO_MMIO_QUEUESEL 0x30
	65	#define VIRTIO_MMIO_QUEUENUMMAX 0x34
	66	#define VIRTIO_MMIO_QUEUENUM 0x38
	67	#define VIRTIO_MMIO_QUEUEALIGN 0x3c
	68	#define VIRTIO_MMIO_QUEUEPFN 0x40
	69	#define VIRTIO_MMIO_QUEUENOTIFY 0x50
	70	#define VIRTIO_MMIO_INTERRUPTSTATUS 0x60
	71	#define VIRTIO_MMIO_INTERRUPTACK 0x64
	72	#define VIRTIO_MMIO_STATUS 0x70
	73	/* Device specific config space starts here */
	74	#define VIRTIO_MMIO_CONFIG 0x100
	75
	76	#define VIRT_MAGIC 0x74726976 /* 'virt' */
	77	#define VIRT_VERSION 1
	78	#define VIRT_VENDOR 0x554D4551 /* 'QEMU' */
	79
	80	typedef struct {
	81	/* Generic */
	82	SysBusDevice parent_obj;
	83	MemoryRegion iomem;
	84	qemu_irq irq;
4b52530b PM	85	/* Guest accessible state needing migration and reset */
	86	uint32_t host_features_sel;
	87	uint32_t guest_features_sel;
	88	uint32_t guest_page_shift;
	89	/* virtio-bus */
	90	VirtioBusState bus;
434027ba YSP	91	bool ioeventfd_disabled;
434027ba YSP	92	bool ioeventfd_started;
4b52530b PM	93	} VirtIOMMIOProxy;
4b52530b PM	94
434027ba YSP	95	static int virtio_mmio_set_host_notifier_internal(VirtIOMMIOProxy *proxy,
	96	int n, bool assign,
	97	bool set_handler)
	98	{
	99	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	100	VirtQueue *vq = virtio_get_queue(vdev, n);
	101	EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
	102	int r = 0;
	103
	104	if (assign) {
	105	r = event_notifier_init(notifier, 1);
	106	if (r < 0) {
	107	error_report("%s: unable to init event notifier: %d",
	108	__func__, r);
	109	return r;
	110	}
	111	virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler);
	112	memory_region_add_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
	113	true, n, notifier);
	114	} else {
	115	memory_region_del_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
	116	true, n, notifier);
	117	virtio_queue_set_host_notifier_fd_handler(vq, false, false);
	118	event_notifier_cleanup(notifier);
	119	}
	120	return r;
	121	}
	122
	123	static void virtio_mmio_start_ioeventfd(VirtIOMMIOProxy *proxy)
	124	{
	125	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	126	int n, r;
	127
	128	if (!kvm_eventfds_enabled() \|\|
	129	proxy->ioeventfd_disabled \|\|
	130	proxy->ioeventfd_started) {
	131	return;
	132	}
	133
	134	for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
	135	if (!virtio_queue_get_num(vdev, n)) {
	136	continue;
	137	}
	138
	139	r = virtio_mmio_set_host_notifier_internal(proxy, n, true, true);
	140	if (r < 0) {
	141	goto assign_error;
	142	}
	143	}
	144	proxy->ioeventfd_started = true;
	145	return;
	146
	147	assign_error:
	148	while (--n >= 0) {
	149	if (!virtio_queue_get_num(vdev, n)) {
	150	continue;
	151	}
	152
	153	r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false);
	154	assert(r >= 0);
	155	}
	156	proxy->ioeventfd_started = false;
	157	error_report("%s: failed. Fallback to a userspace (slower).", __func__);
	158	}
159
160	static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy)
161	{
162	int r;
163	int n;
164	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
165
166	if (!proxy->ioeventfd_started) {
167	return;
168	}
169
170	for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
171	if (!virtio_queue_get_num(vdev, n)) {
172	continue;
173	}
174
175	r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false);
176	assert(r >= 0);
177	}
178	proxy->ioeventfd_started = false;
179	}
180
4b52530b PM	181	static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
	182	{
	183	VirtIOMMIOProxy proxy = (VirtIOMMIOProxy )opaque;
06d3dff0	184	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	185
	186	DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);
	187
	188	if (!vdev) {
	189	/* If no backend is present, we treat most registers as
	190	* read-as-zero, except for the magic number, version and
	191	* vendor ID. This is not strictly sanctioned by the virtio
	192	* spec, but it allows us to provide transports with no backend
	193	* plugged in which don't confuse Linux's virtio code: the
	194	* probe won't complain about the bad magic number, but the
	195	* device ID of zero means no backend will claim it.
	196	*/
	197	switch (offset) {
	198	case VIRTIO_MMIO_MAGIC:
	199	return VIRT_MAGIC;
	200	case VIRTIO_MMIO_VERSION:
	201	return VIRT_VERSION;
	202	case VIRTIO_MMIO_VENDORID:
	203	return VIRT_VENDOR;
	204	default:
	205	return 0;
	206	}
	207	}
	208
	209	if (offset >= VIRTIO_MMIO_CONFIG) {
	210	offset -= VIRTIO_MMIO_CONFIG;
	211	switch (size) {
	212	case 1:
	213	return virtio_config_readb(vdev, offset);
	214	case 2:
	215	return virtio_config_readw(vdev, offset);
	216	case 4:
	217	return virtio_config_readl(vdev, offset);
	218	default:
	219	abort();
	220	}
	221	}
	222	if (size != 4) {
	223	DPRINTF("wrong size access to register!\n");
	224	return 0;
	225	}
	226	switch (offset) {
	227	case VIRTIO_MMIO_MAGIC:
	228	return VIRT_MAGIC;
	229	case VIRTIO_MMIO_VERSION:
	230	return VIRT_VERSION;
	231	case VIRTIO_MMIO_DEVICEID:
	232	return vdev->device_id;
	233	case VIRTIO_MMIO_VENDORID:
	234	return VIRT_VENDOR;
	235	case VIRTIO_MMIO_HOSTFEATURES:
	236	if (proxy->host_features_sel) {
	237	return 0;
	238	}
6b8f1020	239	return vdev->host_features;
4b52530b	240	case VIRTIO_MMIO_QUEUENUMMAX:
f7b803b3 PM	241	if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
	242	return 0;
	243	}
4b52530b PM	244	return VIRTQUEUE_MAX_SIZE;
	245	case VIRTIO_MMIO_QUEUEPFN:
	246	return virtio_queue_get_addr(vdev, vdev->queue_sel)
	247	>> proxy->guest_page_shift;
	248	case VIRTIO_MMIO_INTERRUPTSTATUS:
	249	return vdev->isr;
	250	case VIRTIO_MMIO_STATUS:
	251	return vdev->status;
	252	case VIRTIO_MMIO_HOSTFEATURESSEL:
	253	case VIRTIO_MMIO_GUESTFEATURES:
	254	case VIRTIO_MMIO_GUESTFEATURESSEL:
	255	case VIRTIO_MMIO_GUESTPAGESIZE:
	256	case VIRTIO_MMIO_QUEUESEL:
	257	case VIRTIO_MMIO_QUEUENUM:
	258	case VIRTIO_MMIO_QUEUEALIGN:
	259	case VIRTIO_MMIO_QUEUENOTIFY:
	260	case VIRTIO_MMIO_INTERRUPTACK:
	261	DPRINTF("read of write-only register\n");
	262	return 0;
	263	default:
	264	DPRINTF("bad register offset\n");
	265	return 0;
	266	}
	267	return 0;
	268	}
	269
	270	static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
	271	unsigned size)
	272	{
	273	VirtIOMMIOProxy proxy = (VirtIOMMIOProxy )opaque;
06d3dff0	274	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	275
	276	DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
	277	(int)offset, value);
	278
	279	if (!vdev) {
	280	/* If no backend is present, we just make all registers
	281	* write-ignored. This allows us to provide transports with
	282	* no backend plugged in.
	283	*/
	284	return;
	285	}
	286
	287	if (offset >= VIRTIO_MMIO_CONFIG) {
	288	offset -= VIRTIO_MMIO_CONFIG;
	289	switch (size) {
	290	case 1:
	291	virtio_config_writeb(vdev, offset, value);
	292	break;
	293	case 2:
	294	virtio_config_writew(vdev, offset, value);
	295	break;
	296	case 4:
	297	virtio_config_writel(vdev, offset, value);
	298	break;
	299	default:
	300	abort();
	301	}
	302	return;
	303	}
	304	if (size != 4) {
	305	DPRINTF("wrong size access to register!\n");
	306	return;
	307	}
	308	switch (offset) {
	309	case VIRTIO_MMIO_HOSTFEATURESSEL:
	310	proxy->host_features_sel = value;
	311	break;
	312	case VIRTIO_MMIO_GUESTFEATURES:
	313	if (!proxy->guest_features_sel) {
	314	virtio_set_features(vdev, value);
	315	}
	316	break;
	317	case VIRTIO_MMIO_GUESTFEATURESSEL:
	318	proxy->guest_features_sel = value;
	319	break;
	320	case VIRTIO_MMIO_GUESTPAGESIZE:
	321	proxy->guest_page_shift = ctz32(value);
	322	if (proxy->guest_page_shift > 31) {
	323	proxy->guest_page_shift = 0;
	324	}
	325	DPRINTF("guest page size %" PRIx64 " shift %d\n", value,
	326	proxy->guest_page_shift);
	327	break;
	328	case VIRTIO_MMIO_QUEUESEL:
87b3bd1c	329	if (value < VIRTIO_QUEUE_MAX) {
4b52530b PM	330	vdev->queue_sel = value;
	331	}
	332	break;
	333	case VIRTIO_MMIO_QUEUENUM:
	334	DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE);
	335	virtio_queue_set_num(vdev, vdev->queue_sel, value);
	336	break;
	337	case VIRTIO_MMIO_QUEUEALIGN:
	338	virtio_queue_set_align(vdev, vdev->queue_sel, value);
	339	break;
	340	case VIRTIO_MMIO_QUEUEPFN:
	341	if (value == 0) {
	342	virtio_reset(vdev);
	343	} else {
	344	virtio_queue_set_addr(vdev, vdev->queue_sel,
	345	value << proxy->guest_page_shift);
	346	}
	347	break;
	348	case VIRTIO_MMIO_QUEUENOTIFY:
87b3bd1c	349	if (value < VIRTIO_QUEUE_MAX) {
4b52530b PM	350	virtio_queue_notify(vdev, value);
	351	}
	352	break;
	353	case VIRTIO_MMIO_INTERRUPTACK:
	354	vdev->isr &= ~value;
	355	virtio_update_irq(vdev);
	356	break;
	357	case VIRTIO_MMIO_STATUS:
434027ba YSP	358	if (!(value & VIRTIO_CONFIG_S_DRIVER_OK)) {
	359	virtio_mmio_stop_ioeventfd(proxy);
	360	}
	361
4b52530b	362	virtio_set_status(vdev, value & 0xff);
434027ba YSP	363
	364	if (value & VIRTIO_CONFIG_S_DRIVER_OK) {
	365	virtio_mmio_start_ioeventfd(proxy);
	366	}
	367
4b52530b PM	368	if (vdev->status == 0) {
	369	virtio_reset(vdev);
	370	}
	371	break;
	372	case VIRTIO_MMIO_MAGIC:
	373	case VIRTIO_MMIO_VERSION:
	374	case VIRTIO_MMIO_DEVICEID:
	375	case VIRTIO_MMIO_VENDORID:
	376	case VIRTIO_MMIO_HOSTFEATURES:
	377	case VIRTIO_MMIO_QUEUENUMMAX:
	378	case VIRTIO_MMIO_INTERRUPTSTATUS:
	379	DPRINTF("write to readonly register\n");
	380	break;
	381
	382	default:
	383	DPRINTF("bad register offset\n");
	384	}
	385	}
	386
	387	static const MemoryRegionOps virtio_mem_ops = {
	388	.read = virtio_mmio_read,
	389	.write = virtio_mmio_write,
	390	.endianness = DEVICE_NATIVE_ENDIAN,
	391	};
	392
	393	static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
	394	{
	395	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
06d3dff0	396	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	397	int level;
4b52530b PM	398
06d3dff0	399	if (!vdev) {
4b52530b PM	400	return;
4b52530b PM	401	}
06d3dff0	402	level = (vdev->isr != 0);
4b52530b PM	403	DPRINTF("virtio_mmio setting IRQ %d\n", level);
	404	qemu_set_irq(proxy->irq, level);
	405	}
	406
4b52530b PM	407	static int virtio_mmio_load_config(DeviceState opaque, QEMUFile f)
	408	{
	409	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
	410
	411	proxy->host_features_sel = qemu_get_be32(f);
	412	proxy->guest_features_sel = qemu_get_be32(f);
	413	proxy->guest_page_shift = qemu_get_be32(f);
	414	return 0;
	415	}
	416
	417	static void virtio_mmio_save_config(DeviceState opaque, QEMUFile f)
	418	{
	419	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
	420
	421	qemu_put_be32(f, proxy->host_features_sel);
	422	qemu_put_be32(f, proxy->guest_features_sel);
	423	qemu_put_be32(f, proxy->guest_page_shift);
	424	}
	425
	426	static void virtio_mmio_reset(DeviceState *d)
	427	{
	428	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	429
434027ba	430	virtio_mmio_stop_ioeventfd(proxy);
4b52530b PM	431	virtio_bus_reset(&proxy->bus);
	432	proxy->host_features_sel = 0;
	433	proxy->guest_features_sel = 0;
	434	proxy->guest_page_shift = 0;
	435	}
	436
434027ba YSP	437	static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
	438	bool with_irqfd)
	439	{
	440	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	441	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	442	VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
	443	VirtQueue *vq = virtio_get_queue(vdev, n);
	444	EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
	445
	446	if (assign) {
	447	int r = event_notifier_init(notifier, 0);
	448	if (r < 0) {
	449	return r;
	450	}
	451	virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
	452	} else {
	453	virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
	454	event_notifier_cleanup(notifier);
	455	}
	456
	457	if (vdc->guest_notifier_mask) {
	458	vdc->guest_notifier_mask(vdev, n, !assign);
	459	}
	460
	461	return 0;
	462	}
	463
	464	static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
	465	bool assign)
	466	{
	467	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	468	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	469	/* TODO: need to check if kvm-arm supports irqfd */
	470	bool with_irqfd = false;
	471	int r, n;
	472
	473	nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);
	474
	475	for (n = 0; n < nvqs; n++) {
	476	if (!virtio_queue_get_num(vdev, n)) {
	477	break;
	478	}
	479
	480	r = virtio_mmio_set_guest_notifier(d, n, assign, with_irqfd);
	481	if (r < 0) {
	482	goto assign_error;
	483	}
	484	}
	485
	486	return 0;
	487
	488	assign_error:
	489	/* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
	490	assert(assign);
	491	while (--n >= 0) {
	492	virtio_mmio_set_guest_notifier(d, n, !assign, false);
	493	}
	494	return r;
	495	}
	496
	497	static int virtio_mmio_set_host_notifier(DeviceState *opaque, int n,
	498	bool assign)
	499	{
	500	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
501
502	/* Stop using ioeventfd for virtqueue kick if the device starts using host
503	* notifiers. This makes it easy to avoid stepping on each others' toes.
504	*/
505	proxy->ioeventfd_disabled = assign;
506	if (assign) {
507	virtio_mmio_stop_ioeventfd(proxy);
508	}
509	/* We don't need to start here: it's not needed because backend
510	* currently only stops on status change away from ok,
511	* reset, vmstop and such. If we do add code to start here,
512	* need to check vmstate, device state etc. */
513	return virtio_mmio_set_host_notifier_internal(proxy, n, assign, false);
514	}
515
4b52530b PM	516	/* virtio-mmio device */
4b52530b PM	517
4b52530b PM	518	static void virtio_mmio_realizefn(DeviceState d, Error *errp)
	519	{
	520	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	521	SysBusDevice *sbd = SYS_BUS_DEVICE(d);
	522
2f4f6035 IM	523	qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS,
2f4f6035 IM	524	d, NULL);
4b52530b PM	525	sysbus_init_irq(sbd, &proxy->irq);
	526	memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy,
	527	TYPE_VIRTIO_MMIO, 0x200);
	528	sysbus_init_mmio(sbd, &proxy->iomem);
	529	}
	530
	531	static void virtio_mmio_class_init(ObjectClass klass, void data)
	532	{
	533	DeviceClass *dc = DEVICE_CLASS(klass);
	534
	535	dc->realize = virtio_mmio_realizefn;
	536	dc->reset = virtio_mmio_reset;
125ee0ed	537	set_bit(DEVICE_CATEGORY_MISC, dc->categories);
4b52530b PM	538	}
	539
	540	static const TypeInfo virtio_mmio_info = {
	541	.name = TYPE_VIRTIO_MMIO,
	542	.parent = TYPE_SYS_BUS_DEVICE,
	543	.instance_size = sizeof(VirtIOMMIOProxy),
	544	.class_init = virtio_mmio_class_init,
	545	};
	546
	547	/* virtio-mmio-bus. */
	548
4b52530b PM	549	static void virtio_mmio_bus_class_init(ObjectClass klass, void data)
	550	{
	551	BusClass *bus_class = BUS_CLASS(klass);
	552	VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
	553
	554	k->notify = virtio_mmio_update_irq;
	555	k->save_config = virtio_mmio_save_config;
	556	k->load_config = virtio_mmio_load_config;
434027ba YSP	557	k->set_host_notifier = virtio_mmio_set_host_notifier;
434027ba YSP	558	k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
4b52530b PM	559	k->has_variable_vring_alignment = true;
	560	bus_class->max_dev = 1;
	561	}
	562
	563	static const TypeInfo virtio_mmio_bus_info = {
	564	.name = TYPE_VIRTIO_MMIO_BUS,
	565	.parent = TYPE_VIRTIO_BUS,
	566	.instance_size = sizeof(VirtioBusState),
	567	.class_init = virtio_mmio_bus_class_init,
	568	};
	569
	570	static void virtio_mmio_register_types(void)
	571	{
	572	type_register_static(&virtio_mmio_bus_info);
	573	type_register_static(&virtio_mmio_info);
	574	}
	575
	576	type_init(virtio_mmio_register_types)