[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 "qemu/osdep.h"
#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);
        /* Note: only call this function for legacy devices */
        virtio_queue_update_rings(vdev, vdev->queue_sel);
        break;
    case VIRTIO_MMIO_QUEUEALIGN:
        /* Note: this is only valid for legacy devices */
        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
9b8bfe21	22	#include "qemu/osdep.h"
4b52530b PM	23	#include "hw/sysbus.h"
	24	#include "hw/virtio/virtio.h"
	25	#include "qemu/host-utils.h"
434027ba	26	#include "sysemu/kvm.h"
4b52530b	27	#include "hw/virtio/virtio-bus.h"
434027ba	28	#include "qemu/error-report.h"
4b52530b PM	29
	30	/* #define DEBUG_VIRTIO_MMIO */
	31
	32	#ifdef DEBUG_VIRTIO_MMIO
	33
	34	#define DPRINTF(fmt, ...) \
	35	do { printf("virtio_mmio: " fmt , ## __VA_ARGS__); } while (0)
	36	#else
	37	#define DPRINTF(fmt, ...) do {} while (0)
	38	#endif
	39
	40	/* QOM macros */
	41	/* virtio-mmio-bus */
	42	#define TYPE_VIRTIO_MMIO_BUS "virtio-mmio-bus"
	43	#define VIRTIO_MMIO_BUS(obj) \
	44	OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_MMIO_BUS)
	45	#define VIRTIO_MMIO_BUS_GET_CLASS(obj) \
	46	OBJECT_GET_CLASS(VirtioBusClass, (obj), TYPE_VIRTIO_MMIO_BUS)
	47	#define VIRTIO_MMIO_BUS_CLASS(klass) \
	48	OBJECT_CLASS_CHECK(VirtioBusClass, (klass), TYPE_VIRTIO_MMIO_BUS)
	49
	50	/* virtio-mmio */
	51	#define TYPE_VIRTIO_MMIO "virtio-mmio"
	52	#define VIRTIO_MMIO(obj) \
	53	OBJECT_CHECK(VirtIOMMIOProxy, (obj), TYPE_VIRTIO_MMIO)
	54
	55	/* Memory mapped register offsets */
	56	#define VIRTIO_MMIO_MAGIC 0x0
	57	#define VIRTIO_MMIO_VERSION 0x4
	58	#define VIRTIO_MMIO_DEVICEID 0x8
	59	#define VIRTIO_MMIO_VENDORID 0xc
	60	#define VIRTIO_MMIO_HOSTFEATURES 0x10
	61	#define VIRTIO_MMIO_HOSTFEATURESSEL 0x14
	62	#define VIRTIO_MMIO_GUESTFEATURES 0x20
	63	#define VIRTIO_MMIO_GUESTFEATURESSEL 0x24
	64	#define VIRTIO_MMIO_GUESTPAGESIZE 0x28
	65	#define VIRTIO_MMIO_QUEUESEL 0x30
	66	#define VIRTIO_MMIO_QUEUENUMMAX 0x34
	67	#define VIRTIO_MMIO_QUEUENUM 0x38
	68	#define VIRTIO_MMIO_QUEUEALIGN 0x3c
	69	#define VIRTIO_MMIO_QUEUEPFN 0x40
	70	#define VIRTIO_MMIO_QUEUENOTIFY 0x50
	71	#define VIRTIO_MMIO_INTERRUPTSTATUS 0x60
	72	#define VIRTIO_MMIO_INTERRUPTACK 0x64
	73	#define VIRTIO_MMIO_STATUS 0x70
	74	/* Device specific config space starts here */
	75	#define VIRTIO_MMIO_CONFIG 0x100
	76
	77	#define VIRT_MAGIC 0x74726976 /* 'virt' */
	78	#define VIRT_VERSION 1
	79	#define VIRT_VENDOR 0x554D4551 /* 'QEMU' */
	80
	81	typedef struct {
	82	/* Generic */
	83	SysBusDevice parent_obj;
	84	MemoryRegion iomem;
	85	qemu_irq irq;
4b52530b PM	86	/* Guest accessible state needing migration and reset */
	87	uint32_t host_features_sel;
	88	uint32_t guest_features_sel;
	89	uint32_t guest_page_shift;
	90	/* virtio-bus */
	91	VirtioBusState bus;
434027ba YSP	92	bool ioeventfd_disabled;
434027ba YSP	93	bool ioeventfd_started;
4b52530b PM	94	} VirtIOMMIOProxy;
4b52530b PM	95
434027ba YSP	96	static int virtio_mmio_set_host_notifier_internal(VirtIOMMIOProxy *proxy,
	97	int n, bool assign,
	98	bool set_handler)
	99	{
	100	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	101	VirtQueue *vq = virtio_get_queue(vdev, n);
	102	EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
	103	int r = 0;
	104
	105	if (assign) {
	106	r = event_notifier_init(notifier, 1);
	107	if (r < 0) {
	108	error_report("%s: unable to init event notifier: %d",
	109	__func__, r);
	110	return r;
	111	}
	112	virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler);
	113	memory_region_add_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
	114	true, n, notifier);
	115	} else {
	116	memory_region_del_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
	117	true, n, notifier);
	118	virtio_queue_set_host_notifier_fd_handler(vq, false, false);
	119	event_notifier_cleanup(notifier);
	120	}
	121	return r;
	122	}
	123
	124	static void virtio_mmio_start_ioeventfd(VirtIOMMIOProxy *proxy)
	125	{
	126	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	127	int n, r;
	128
	129	if (!kvm_eventfds_enabled() \|\|
	130	proxy->ioeventfd_disabled \|\|
	131	proxy->ioeventfd_started) {
	132	return;
	133	}
	134
	135	for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
	136	if (!virtio_queue_get_num(vdev, n)) {
	137	continue;
	138	}
	139
	140	r = virtio_mmio_set_host_notifier_internal(proxy, n, true, true);
	141	if (r < 0) {
	142	goto assign_error;
	143	}
	144	}
	145	proxy->ioeventfd_started = true;
	146	return;
	147
	148	assign_error:
	149	while (--n >= 0) {
	150	if (!virtio_queue_get_num(vdev, n)) {
	151	continue;
	152	}
	153
	154	r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false);
	155	assert(r >= 0);
	156	}
	157	proxy->ioeventfd_started = false;
	158	error_report("%s: failed. Fallback to a userspace (slower).", __func__);
	159	}
160
161	static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy)
162	{
163	int r;
164	int n;
165	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
166
167	if (!proxy->ioeventfd_started) {
168	return;
169	}
170
171	for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
172	if (!virtio_queue_get_num(vdev, n)) {
173	continue;
174	}
175
176	r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false);
177	assert(r >= 0);
178	}
179	proxy->ioeventfd_started = false;
180	}
181
4b52530b PM	182	static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
	183	{
	184	VirtIOMMIOProxy proxy = (VirtIOMMIOProxy )opaque;
06d3dff0	185	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	186
	187	DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);
	188
	189	if (!vdev) {
	190	/* If no backend is present, we treat most registers as
	191	* read-as-zero, except for the magic number, version and
	192	* vendor ID. This is not strictly sanctioned by the virtio
	193	* spec, but it allows us to provide transports with no backend
	194	* plugged in which don't confuse Linux's virtio code: the
	195	* probe won't complain about the bad magic number, but the
	196	* device ID of zero means no backend will claim it.
	197	*/
	198	switch (offset) {
	199	case VIRTIO_MMIO_MAGIC:
	200	return VIRT_MAGIC;
	201	case VIRTIO_MMIO_VERSION:
	202	return VIRT_VERSION;
	203	case VIRTIO_MMIO_VENDORID:
	204	return VIRT_VENDOR;
	205	default:
	206	return 0;
	207	}
	208	}
	209
	210	if (offset >= VIRTIO_MMIO_CONFIG) {
	211	offset -= VIRTIO_MMIO_CONFIG;
	212	switch (size) {
	213	case 1:
	214	return virtio_config_readb(vdev, offset);
	215	case 2:
	216	return virtio_config_readw(vdev, offset);
	217	case 4:
	218	return virtio_config_readl(vdev, offset);
	219	default:
	220	abort();
	221	}
	222	}
	223	if (size != 4) {
	224	DPRINTF("wrong size access to register!\n");
	225	return 0;
	226	}
	227	switch (offset) {
	228	case VIRTIO_MMIO_MAGIC:
	229	return VIRT_MAGIC;
	230	case VIRTIO_MMIO_VERSION:
	231	return VIRT_VERSION;
	232	case VIRTIO_MMIO_DEVICEID:
	233	return vdev->device_id;
	234	case VIRTIO_MMIO_VENDORID:
	235	return VIRT_VENDOR;
	236	case VIRTIO_MMIO_HOSTFEATURES:
	237	if (proxy->host_features_sel) {
	238	return 0;
	239	}
6b8f1020	240	return vdev->host_features;
4b52530b	241	case VIRTIO_MMIO_QUEUENUMMAX:
f7b803b3 PM	242	if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
	243	return 0;
	244	}
4b52530b PM	245	return VIRTQUEUE_MAX_SIZE;
	246	case VIRTIO_MMIO_QUEUEPFN:
	247	return virtio_queue_get_addr(vdev, vdev->queue_sel)
	248	>> proxy->guest_page_shift;
	249	case VIRTIO_MMIO_INTERRUPTSTATUS:
	250	return vdev->isr;
	251	case VIRTIO_MMIO_STATUS:
	252	return vdev->status;
	253	case VIRTIO_MMIO_HOSTFEATURESSEL:
	254	case VIRTIO_MMIO_GUESTFEATURES:
	255	case VIRTIO_MMIO_GUESTFEATURESSEL:
	256	case VIRTIO_MMIO_GUESTPAGESIZE:
	257	case VIRTIO_MMIO_QUEUESEL:
	258	case VIRTIO_MMIO_QUEUENUM:
	259	case VIRTIO_MMIO_QUEUEALIGN:
	260	case VIRTIO_MMIO_QUEUENOTIFY:
	261	case VIRTIO_MMIO_INTERRUPTACK:
	262	DPRINTF("read of write-only register\n");
	263	return 0;
	264	default:
	265	DPRINTF("bad register offset\n");
	266	return 0;
	267	}
	268	return 0;
	269	}
	270
	271	static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
	272	unsigned size)
	273	{
	274	VirtIOMMIOProxy proxy = (VirtIOMMIOProxy )opaque;
06d3dff0	275	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	276
	277	DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
	278	(int)offset, value);
	279
	280	if (!vdev) {
	281	/* If no backend is present, we just make all registers
	282	* write-ignored. This allows us to provide transports with
	283	* no backend plugged in.
	284	*/
	285	return;
	286	}
	287
	288	if (offset >= VIRTIO_MMIO_CONFIG) {
	289	offset -= VIRTIO_MMIO_CONFIG;
	290	switch (size) {
	291	case 1:
	292	virtio_config_writeb(vdev, offset, value);
	293	break;
	294	case 2:
	295	virtio_config_writew(vdev, offset, value);
	296	break;
	297	case 4:
	298	virtio_config_writel(vdev, offset, value);
	299	break;
	300	default:
	301	abort();
	302	}
	303	return;
	304	}
	305	if (size != 4) {
	306	DPRINTF("wrong size access to register!\n");
	307	return;
	308	}
	309	switch (offset) {
	310	case VIRTIO_MMIO_HOSTFEATURESSEL:
	311	proxy->host_features_sel = value;
	312	break;
	313	case VIRTIO_MMIO_GUESTFEATURES:
	314	if (!proxy->guest_features_sel) {
	315	virtio_set_features(vdev, value);
	316	}
	317	break;
	318	case VIRTIO_MMIO_GUESTFEATURESSEL:
	319	proxy->guest_features_sel = value;
	320	break;
	321	case VIRTIO_MMIO_GUESTPAGESIZE:
	322	proxy->guest_page_shift = ctz32(value);
	323	if (proxy->guest_page_shift > 31) {
	324	proxy->guest_page_shift = 0;
	325	}
	326	DPRINTF("guest page size %" PRIx64 " shift %d\n", value,
	327	proxy->guest_page_shift);
	328	break;
	329	case VIRTIO_MMIO_QUEUESEL:
87b3bd1c	330	if (value < VIRTIO_QUEUE_MAX) {
4b52530b PM	331	vdev->queue_sel = value;
	332	}
	333	break;
	334	case VIRTIO_MMIO_QUEUENUM:
	335	DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE);
	336	virtio_queue_set_num(vdev, vdev->queue_sel, value);
ab223c95 CH	337	/* Note: only call this function for legacy devices */
ab223c95 CH	338	virtio_queue_update_rings(vdev, vdev->queue_sel);
4b52530b PM	339	break;
4b52530b PM	340	case VIRTIO_MMIO_QUEUEALIGN:
ab223c95	341	/* Note: this is only valid for legacy devices */
4b52530b PM	342	virtio_queue_set_align(vdev, vdev->queue_sel, value);
	343	break;
	344	case VIRTIO_MMIO_QUEUEPFN:
	345	if (value == 0) {
	346	virtio_reset(vdev);
	347	} else {
	348	virtio_queue_set_addr(vdev, vdev->queue_sel,
	349	value << proxy->guest_page_shift);
	350	}
	351	break;
	352	case VIRTIO_MMIO_QUEUENOTIFY:
87b3bd1c	353	if (value < VIRTIO_QUEUE_MAX) {
4b52530b PM	354	virtio_queue_notify(vdev, value);
	355	}
	356	break;
	357	case VIRTIO_MMIO_INTERRUPTACK:
	358	vdev->isr &= ~value;
	359	virtio_update_irq(vdev);
	360	break;
	361	case VIRTIO_MMIO_STATUS:
434027ba YSP	362	if (!(value & VIRTIO_CONFIG_S_DRIVER_OK)) {
	363	virtio_mmio_stop_ioeventfd(proxy);
	364	}
	365
4b52530b	366	virtio_set_status(vdev, value & 0xff);
434027ba YSP	367
	368	if (value & VIRTIO_CONFIG_S_DRIVER_OK) {
	369	virtio_mmio_start_ioeventfd(proxy);
	370	}
	371
4b52530b PM	372	if (vdev->status == 0) {
	373	virtio_reset(vdev);
	374	}
	375	break;
	376	case VIRTIO_MMIO_MAGIC:
	377	case VIRTIO_MMIO_VERSION:
	378	case VIRTIO_MMIO_DEVICEID:
	379	case VIRTIO_MMIO_VENDORID:
	380	case VIRTIO_MMIO_HOSTFEATURES:
	381	case VIRTIO_MMIO_QUEUENUMMAX:
	382	case VIRTIO_MMIO_INTERRUPTSTATUS:
	383	DPRINTF("write to readonly register\n");
	384	break;
	385
	386	default:
	387	DPRINTF("bad register offset\n");
	388	}
	389	}
	390
	391	static const MemoryRegionOps virtio_mem_ops = {
	392	.read = virtio_mmio_read,
	393	.write = virtio_mmio_write,
	394	.endianness = DEVICE_NATIVE_ENDIAN,
	395	};
	396
	397	static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
	398	{
	399	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
06d3dff0	400	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	401	int level;
4b52530b PM	402
06d3dff0	403	if (!vdev) {
4b52530b PM	404	return;
4b52530b PM	405	}
06d3dff0	406	level = (vdev->isr != 0);
4b52530b PM	407	DPRINTF("virtio_mmio setting IRQ %d\n", level);
	408	qemu_set_irq(proxy->irq, level);
	409	}
	410
4b52530b PM	411	static int virtio_mmio_load_config(DeviceState opaque, QEMUFile f)
	412	{
	413	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
	414
	415	proxy->host_features_sel = qemu_get_be32(f);
	416	proxy->guest_features_sel = qemu_get_be32(f);
	417	proxy->guest_page_shift = qemu_get_be32(f);
	418	return 0;
	419	}
	420
	421	static void virtio_mmio_save_config(DeviceState opaque, QEMUFile f)
	422	{
	423	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
	424
	425	qemu_put_be32(f, proxy->host_features_sel);
	426	qemu_put_be32(f, proxy->guest_features_sel);
	427	qemu_put_be32(f, proxy->guest_page_shift);
	428	}
	429
	430	static void virtio_mmio_reset(DeviceState *d)
	431	{
	432	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	433
434027ba	434	virtio_mmio_stop_ioeventfd(proxy);
4b52530b PM	435	virtio_bus_reset(&proxy->bus);
	436	proxy->host_features_sel = 0;
	437	proxy->guest_features_sel = 0;
	438	proxy->guest_page_shift = 0;
	439	}
	440
434027ba YSP	441	static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
	442	bool with_irqfd)
	443	{
	444	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	445	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	446	VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
	447	VirtQueue *vq = virtio_get_queue(vdev, n);
	448	EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
	449
	450	if (assign) {
	451	int r = event_notifier_init(notifier, 0);
	452	if (r < 0) {
	453	return r;
	454	}
	455	virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
	456	} else {
	457	virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
	458	event_notifier_cleanup(notifier);
	459	}
	460
	461	if (vdc->guest_notifier_mask) {
	462	vdc->guest_notifier_mask(vdev, n, !assign);
	463	}
	464
	465	return 0;
	466	}
	467
	468	static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
	469	bool assign)
	470	{
	471	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	472	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	473	/* TODO: need to check if kvm-arm supports irqfd */
	474	bool with_irqfd = false;
	475	int r, n;
	476
	477	nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);
	478
	479	for (n = 0; n < nvqs; n++) {
	480	if (!virtio_queue_get_num(vdev, n)) {
	481	break;
	482	}
	483
	484	r = virtio_mmio_set_guest_notifier(d, n, assign, with_irqfd);
	485	if (r < 0) {
	486	goto assign_error;
	487	}
	488	}
	489
	490	return 0;
	491
	492	assign_error:
	493	/* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
	494	assert(assign);
	495	while (--n >= 0) {
	496	virtio_mmio_set_guest_notifier(d, n, !assign, false);
	497	}
	498	return r;
	499	}
	500
	501	static int virtio_mmio_set_host_notifier(DeviceState *opaque, int n,
	502	bool assign)
	503	{
	504	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
505
506	/* Stop using ioeventfd for virtqueue kick if the device starts using host
507	* notifiers. This makes it easy to avoid stepping on each others' toes.
508	*/
509	proxy->ioeventfd_disabled = assign;
510	if (assign) {
511	virtio_mmio_stop_ioeventfd(proxy);
512	}
513	/* We don't need to start here: it's not needed because backend
514	* currently only stops on status change away from ok,
515	* reset, vmstop and such. If we do add code to start here,
516	* need to check vmstate, device state etc. */
517	return virtio_mmio_set_host_notifier_internal(proxy, n, assign, false);
518	}
519
4b52530b PM	520	/* virtio-mmio device */
4b52530b PM	521
4b52530b PM	522	static void virtio_mmio_realizefn(DeviceState d, Error *errp)
	523	{
	524	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	525	SysBusDevice *sbd = SYS_BUS_DEVICE(d);
	526
2f4f6035 IM	527	qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS,
2f4f6035 IM	528	d, NULL);
4b52530b PM	529	sysbus_init_irq(sbd, &proxy->irq);
	530	memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy,
	531	TYPE_VIRTIO_MMIO, 0x200);
	532	sysbus_init_mmio(sbd, &proxy->iomem);
	533	}
	534
	535	static void virtio_mmio_class_init(ObjectClass klass, void data)
	536	{
	537	DeviceClass *dc = DEVICE_CLASS(klass);
	538
	539	dc->realize = virtio_mmio_realizefn;
	540	dc->reset = virtio_mmio_reset;
125ee0ed	541	set_bit(DEVICE_CATEGORY_MISC, dc->categories);
4b52530b PM	542	}
	543
	544	static const TypeInfo virtio_mmio_info = {
	545	.name = TYPE_VIRTIO_MMIO,
	546	.parent = TYPE_SYS_BUS_DEVICE,
	547	.instance_size = sizeof(VirtIOMMIOProxy),
	548	.class_init = virtio_mmio_class_init,
	549	};
	550
	551	/* virtio-mmio-bus. */
	552
4b52530b PM	553	static void virtio_mmio_bus_class_init(ObjectClass klass, void data)
	554	{
	555	BusClass *bus_class = BUS_CLASS(klass);
	556	VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
	557
	558	k->notify = virtio_mmio_update_irq;
	559	k->save_config = virtio_mmio_save_config;
	560	k->load_config = virtio_mmio_load_config;
434027ba YSP	561	k->set_host_notifier = virtio_mmio_set_host_notifier;
434027ba YSP	562	k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
4b52530b PM	563	k->has_variable_vring_alignment = true;
	564	bus_class->max_dev = 1;
	565	}
	566
	567	static const TypeInfo virtio_mmio_bus_info = {
	568	.name = TYPE_VIRTIO_MMIO_BUS,
	569	.parent = TYPE_VIRTIO_BUS,
	570	.instance_size = sizeof(VirtioBusState),
	571	.class_init = virtio_mmio_bus_class_init,
	572	};
	573
	574	static void virtio_mmio_register_types(void)
	575	{
	576	type_register_static(&virtio_mmio_bus_info);
	577	type_register_static(&virtio_mmio_info);
	578	}
	579
	580	type_init(virtio_mmio_register_types)