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

/*
 * Virtio MMIO bindings
 *
 * Copyright (c) 2011 Linaro Limited
 *
 * Author:
 *  Peter Maydell <peter.maydell@linaro.org>
 *
 * 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 format_transport_address;
} VirtIOMMIOProxy;

static bool virtio_mmio_ioeventfd_enabled(DeviceState *d)
{
    return kvm_eventfds_enabled();
}

static int virtio_mmio_ioeventfd_assign(DeviceState *d,
                                        EventNotifier *notifier,
                                        int n, bool assign)
{
    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);

    if (assign) {
        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);
    }
    return 0;
}

static void virtio_mmio_start_ioeventfd(VirtIOMMIOProxy *proxy)
{
    virtio_bus_start_ioeventfd(&proxy->bus);
}

static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy)
{
    virtio_bus_stop_ioeventfd(&proxy->bus);
}

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 atomic_read(&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:
        atomic_and(&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 = (atomic_read(&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 && vdev->use_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;
}

/* virtio-mmio device */

static Property virtio_mmio_properties[] = {
    DEFINE_PROP_BOOL("format_transport_address", VirtIOMMIOProxy,
                     format_transport_address, true),
    DEFINE_PROP_END_OF_LIST(),
};

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);
    dc->props = virtio_mmio_properties;
}

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 char *virtio_mmio_bus_get_dev_path(DeviceState *dev)
{
    BusState *virtio_mmio_bus;
    VirtIOMMIOProxy *virtio_mmio_proxy;
    char *proxy_path;
    SysBusDevice *proxy_sbd;
    char *path;

    virtio_mmio_bus = qdev_get_parent_bus(dev);
    virtio_mmio_proxy = VIRTIO_MMIO(virtio_mmio_bus->parent);
    proxy_path = qdev_get_dev_path(DEVICE(virtio_mmio_proxy));

    /*
     * If @format_transport_address is false, then we just perform the same as
     * virtio_bus_get_dev_path(): we delegate the address formatting for the
     * device on the virtio-mmio bus to the bus that the virtio-mmio proxy
     * (i.e., the device that implements the virtio-mmio bus) resides on. In
     * this case the base address of the virtio-mmio transport will be
     * invisible.
     */
    if (!virtio_mmio_proxy->format_transport_address) {
        return proxy_path;
    }

    /* Otherwise, we append the base address of the transport. */
    proxy_sbd = SYS_BUS_DEVICE(virtio_mmio_proxy);
    assert(proxy_sbd->num_mmio == 1);
    assert(proxy_sbd->mmio[0].memory == &virtio_mmio_proxy->iomem);

    if (proxy_path) {
        path = g_strdup_printf("%s/virtio-mmio@" TARGET_FMT_plx, proxy_path,
                               proxy_sbd->mmio[0].addr);
    } else {
        path = g_strdup_printf("virtio-mmio@" TARGET_FMT_plx,
                               proxy_sbd->mmio[0].addr);
    }
    g_free(proxy_path);
    return path;
}

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_guest_notifiers = virtio_mmio_set_guest_notifiers;
    k->ioeventfd_enabled = virtio_mmio_ioeventfd_enabled;
    k->ioeventfd_assign = virtio_mmio_ioeventfd_assign;
    k->has_variable_vring_alignment = true;
    bus_class->max_dev = 1;
    bus_class->get_dev_path = virtio_mmio_bus_get_dev_path;
}

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 <peter.maydell@linaro.org>
	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;
f58b39d2	92	bool format_transport_address;
4b52530b PM	93	} VirtIOMMIOProxy;
4b52530b PM	94
8e93cef1	95	static bool virtio_mmio_ioeventfd_enabled(DeviceState *d)
c0971bcb	96	{
8e93cef1	97	return kvm_eventfds_enabled();
434027ba YSP	98	}
434027ba YSP	99
c0971bcb CH	100	static int virtio_mmio_ioeventfd_assign(DeviceState *d,
	101	EventNotifier *notifier,
	102	int n, bool assign)
434027ba	103	{
c0971bcb	104	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
434027ba	105
c0971bcb CH	106	if (assign) {
	107	memory_region_add_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
	108	true, n, notifier);
	109	} else {
	110	memory_region_del_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY, 4,
	111	true, n, notifier);
434027ba	112	}
c0971bcb CH	113	return 0;
c0971bcb CH	114	}
434027ba	115
c0971bcb CH	116	static void virtio_mmio_start_ioeventfd(VirtIOMMIOProxy *proxy)
	117	{
	118	virtio_bus_start_ioeventfd(&proxy->bus);
	119	}
434027ba	120
c0971bcb CH	121	static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy)
	122	{
	123	virtio_bus_stop_ioeventfd(&proxy->bus);
434027ba YSP	124	}
434027ba YSP	125
4b52530b PM	126	static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
	127	{
	128	VirtIOMMIOProxy proxy = (VirtIOMMIOProxy )opaque;
06d3dff0	129	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	130
	131	DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);
	132
	133	if (!vdev) {
	134	/* If no backend is present, we treat most registers as
	135	* read-as-zero, except for the magic number, version and
	136	* vendor ID. This is not strictly sanctioned by the virtio
	137	* spec, but it allows us to provide transports with no backend
	138	* plugged in which don't confuse Linux's virtio code: the
	139	* probe won't complain about the bad magic number, but the
	140	* device ID of zero means no backend will claim it.
	141	*/
	142	switch (offset) {
	143	case VIRTIO_MMIO_MAGIC:
	144	return VIRT_MAGIC;
	145	case VIRTIO_MMIO_VERSION:
	146	return VIRT_VERSION;
	147	case VIRTIO_MMIO_VENDORID:
	148	return VIRT_VENDOR;
	149	default:
	150	return 0;
	151	}
	152	}
	153
	154	if (offset >= VIRTIO_MMIO_CONFIG) {
	155	offset -= VIRTIO_MMIO_CONFIG;
	156	switch (size) {
	157	case 1:
	158	return virtio_config_readb(vdev, offset);
	159	case 2:
	160	return virtio_config_readw(vdev, offset);
	161	case 4:
	162	return virtio_config_readl(vdev, offset);
	163	default:
	164	abort();
	165	}
	166	}
	167	if (size != 4) {
	168	DPRINTF("wrong size access to register!\n");
	169	return 0;
	170	}
	171	switch (offset) {
	172	case VIRTIO_MMIO_MAGIC:
	173	return VIRT_MAGIC;
	174	case VIRTIO_MMIO_VERSION:
	175	return VIRT_VERSION;
	176	case VIRTIO_MMIO_DEVICEID:
	177	return vdev->device_id;
	178	case VIRTIO_MMIO_VENDORID:
	179	return VIRT_VENDOR;
	180	case VIRTIO_MMIO_HOSTFEATURES:
	181	if (proxy->host_features_sel) {
	182	return 0;
	183	}
6b8f1020	184	return vdev->host_features;
4b52530b	185	case VIRTIO_MMIO_QUEUENUMMAX:
f7b803b3 PM	186	if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
	187	return 0;
	188	}
4b52530b PM	189	return VIRTQUEUE_MAX_SIZE;
	190	case VIRTIO_MMIO_QUEUEPFN:
	191	return virtio_queue_get_addr(vdev, vdev->queue_sel)
	192	>> proxy->guest_page_shift;
	193	case VIRTIO_MMIO_INTERRUPTSTATUS:
0687c37c	194	return atomic_read(&vdev->isr);
4b52530b PM	195	case VIRTIO_MMIO_STATUS:
	196	return vdev->status;
	197	case VIRTIO_MMIO_HOSTFEATURESSEL:
	198	case VIRTIO_MMIO_GUESTFEATURES:
	199	case VIRTIO_MMIO_GUESTFEATURESSEL:
	200	case VIRTIO_MMIO_GUESTPAGESIZE:
	201	case VIRTIO_MMIO_QUEUESEL:
	202	case VIRTIO_MMIO_QUEUENUM:
	203	case VIRTIO_MMIO_QUEUEALIGN:
	204	case VIRTIO_MMIO_QUEUENOTIFY:
	205	case VIRTIO_MMIO_INTERRUPTACK:
	206	DPRINTF("read of write-only register\n");
	207	return 0;
	208	default:
	209	DPRINTF("bad register offset\n");
	210	return 0;
	211	}
	212	return 0;
	213	}
	214
	215	static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
	216	unsigned size)
	217	{
	218	VirtIOMMIOProxy proxy = (VirtIOMMIOProxy )opaque;
06d3dff0	219	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	220
	221	DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
	222	(int)offset, value);
	223
	224	if (!vdev) {
	225	/* If no backend is present, we just make all registers
	226	* write-ignored. This allows us to provide transports with
	227	* no backend plugged in.
	228	*/
	229	return;
	230	}
	231
	232	if (offset >= VIRTIO_MMIO_CONFIG) {
	233	offset -= VIRTIO_MMIO_CONFIG;
	234	switch (size) {
	235	case 1:
	236	virtio_config_writeb(vdev, offset, value);
	237	break;
	238	case 2:
	239	virtio_config_writew(vdev, offset, value);
	240	break;
	241	case 4:
	242	virtio_config_writel(vdev, offset, value);
	243	break;
	244	default:
	245	abort();
	246	}
	247	return;
	248	}
	249	if (size != 4) {
	250	DPRINTF("wrong size access to register!\n");
	251	return;
	252	}
	253	switch (offset) {
	254	case VIRTIO_MMIO_HOSTFEATURESSEL:
	255	proxy->host_features_sel = value;
	256	break;
	257	case VIRTIO_MMIO_GUESTFEATURES:
	258	if (!proxy->guest_features_sel) {
	259	virtio_set_features(vdev, value);
	260	}
	261	break;
	262	case VIRTIO_MMIO_GUESTFEATURESSEL:
	263	proxy->guest_features_sel = value;
	264	break;
	265	case VIRTIO_MMIO_GUESTPAGESIZE:
	266	proxy->guest_page_shift = ctz32(value);
	267	if (proxy->guest_page_shift > 31) {
	268	proxy->guest_page_shift = 0;
	269	}
	270	DPRINTF("guest page size %" PRIx64 " shift %d\n", value,
	271	proxy->guest_page_shift);
	272	break;
	273	case VIRTIO_MMIO_QUEUESEL:
87b3bd1c	274	if (value < VIRTIO_QUEUE_MAX) {
4b52530b PM	275	vdev->queue_sel = value;
	276	}
	277	break;
	278	case VIRTIO_MMIO_QUEUENUM:
	279	DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE);
	280	virtio_queue_set_num(vdev, vdev->queue_sel, value);
ab223c95 CH	281	/* Note: only call this function for legacy devices */
ab223c95 CH	282	virtio_queue_update_rings(vdev, vdev->queue_sel);
4b52530b PM	283	break;
4b52530b PM	284	case VIRTIO_MMIO_QUEUEALIGN:
ab223c95	285	/* Note: this is only valid for legacy devices */
4b52530b PM	286	virtio_queue_set_align(vdev, vdev->queue_sel, value);
	287	break;
	288	case VIRTIO_MMIO_QUEUEPFN:
	289	if (value == 0) {
	290	virtio_reset(vdev);
	291	} else {
	292	virtio_queue_set_addr(vdev, vdev->queue_sel,
	293	value << proxy->guest_page_shift);
	294	}
	295	break;
	296	case VIRTIO_MMIO_QUEUENOTIFY:
87b3bd1c	297	if (value < VIRTIO_QUEUE_MAX) {
4b52530b PM	298	virtio_queue_notify(vdev, value);
	299	}
	300	break;
	301	case VIRTIO_MMIO_INTERRUPTACK:
0687c37c	302	atomic_and(&vdev->isr, ~value);
4b52530b PM	303	virtio_update_irq(vdev);
	304	break;
	305	case VIRTIO_MMIO_STATUS:
434027ba YSP	306	if (!(value & VIRTIO_CONFIG_S_DRIVER_OK)) {
	307	virtio_mmio_stop_ioeventfd(proxy);
	308	}
	309
4b52530b	310	virtio_set_status(vdev, value & 0xff);
434027ba YSP	311
	312	if (value & VIRTIO_CONFIG_S_DRIVER_OK) {
	313	virtio_mmio_start_ioeventfd(proxy);
	314	}
	315
4b52530b PM	316	if (vdev->status == 0) {
	317	virtio_reset(vdev);
	318	}
	319	break;
	320	case VIRTIO_MMIO_MAGIC:
	321	case VIRTIO_MMIO_VERSION:
	322	case VIRTIO_MMIO_DEVICEID:
	323	case VIRTIO_MMIO_VENDORID:
	324	case VIRTIO_MMIO_HOSTFEATURES:
	325	case VIRTIO_MMIO_QUEUENUMMAX:
	326	case VIRTIO_MMIO_INTERRUPTSTATUS:
	327	DPRINTF("write to readonly register\n");
	328	break;
	329
	330	default:
	331	DPRINTF("bad register offset\n");
	332	}
	333	}
	334
	335	static const MemoryRegionOps virtio_mem_ops = {
	336	.read = virtio_mmio_read,
	337	.write = virtio_mmio_write,
	338	.endianness = DEVICE_NATIVE_ENDIAN,
	339	};
	340
	341	static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
	342	{
	343	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
06d3dff0	344	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
4b52530b PM	345	int level;
4b52530b PM	346
06d3dff0	347	if (!vdev) {
4b52530b PM	348	return;
4b52530b PM	349	}
0687c37c	350	level = (atomic_read(&vdev->isr) != 0);
4b52530b PM	351	DPRINTF("virtio_mmio setting IRQ %d\n", level);
	352	qemu_set_irq(proxy->irq, level);
	353	}
	354
4b52530b PM	355	static int virtio_mmio_load_config(DeviceState opaque, QEMUFile f)
	356	{
	357	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
	358
	359	proxy->host_features_sel = qemu_get_be32(f);
	360	proxy->guest_features_sel = qemu_get_be32(f);
	361	proxy->guest_page_shift = qemu_get_be32(f);
	362	return 0;
	363	}
	364
	365	static void virtio_mmio_save_config(DeviceState opaque, QEMUFile f)
	366	{
	367	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
	368
	369	qemu_put_be32(f, proxy->host_features_sel);
	370	qemu_put_be32(f, proxy->guest_features_sel);
	371	qemu_put_be32(f, proxy->guest_page_shift);
	372	}
	373
	374	static void virtio_mmio_reset(DeviceState *d)
	375	{
	376	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	377
434027ba	378	virtio_mmio_stop_ioeventfd(proxy);
4b52530b PM	379	virtio_bus_reset(&proxy->bus);
	380	proxy->host_features_sel = 0;
	381	proxy->guest_features_sel = 0;
	382	proxy->guest_page_shift = 0;
	383	}
	384
434027ba YSP	385	static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
	386	bool with_irqfd)
	387	{
	388	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	389	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	390	VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
	391	VirtQueue *vq = virtio_get_queue(vdev, n);
	392	EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
	393
	394	if (assign) {
	395	int r = event_notifier_init(notifier, 0);
	396	if (r < 0) {
	397	return r;
	398	}
	399	virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
	400	} else {
	401	virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
	402	event_notifier_cleanup(notifier);
	403	}
	404
2858bc68	405	if (vdc->guest_notifier_mask && vdev->use_guest_notifier_mask) {
434027ba YSP	406	vdc->guest_notifier_mask(vdev, n, !assign);
	407	}
	408
	409	return 0;
	410	}
	411
	412	static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
	413	bool assign)
	414	{
	415	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	416	VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
	417	/* TODO: need to check if kvm-arm supports irqfd */
	418	bool with_irqfd = false;
	419	int r, n;
	420
	421	nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);
	422
	423	for (n = 0; n < nvqs; n++) {
	424	if (!virtio_queue_get_num(vdev, n)) {
	425	break;
	426	}
	427
	428	r = virtio_mmio_set_guest_notifier(d, n, assign, with_irqfd);
	429	if (r < 0) {
	430	goto assign_error;
	431	}
	432	}
	433
	434	return 0;
	435
	436	assign_error:
	437	/* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
	438	assert(assign);
	439	while (--n >= 0) {
	440	virtio_mmio_set_guest_notifier(d, n, !assign, false);
	441	}
	442	return r;
	443	}
	444
4b52530b PM	445	/* virtio-mmio device */
4b52530b PM	446
f58b39d2 LE	447	static Property virtio_mmio_properties[] = {
	448	DEFINE_PROP_BOOL("format_transport_address", VirtIOMMIOProxy,
	449	format_transport_address, true),
	450	DEFINE_PROP_END_OF_LIST(),
	451	};
	452
4b52530b PM	453	static void virtio_mmio_realizefn(DeviceState d, Error *errp)
	454	{
	455	VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
	456	SysBusDevice *sbd = SYS_BUS_DEVICE(d);
	457
2f4f6035 IM	458	qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS,
2f4f6035 IM	459	d, NULL);
4b52530b PM	460	sysbus_init_irq(sbd, &proxy->irq);
	461	memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy,
	462	TYPE_VIRTIO_MMIO, 0x200);
	463	sysbus_init_mmio(sbd, &proxy->iomem);
	464	}
	465
	466	static void virtio_mmio_class_init(ObjectClass klass, void data)
	467	{
	468	DeviceClass *dc = DEVICE_CLASS(klass);
	469
	470	dc->realize = virtio_mmio_realizefn;
	471	dc->reset = virtio_mmio_reset;
125ee0ed	472	set_bit(DEVICE_CATEGORY_MISC, dc->categories);
f58b39d2	473	dc->props = virtio_mmio_properties;
4b52530b PM	474	}
	475
	476	static const TypeInfo virtio_mmio_info = {
	477	.name = TYPE_VIRTIO_MMIO,
	478	.parent = TYPE_SYS_BUS_DEVICE,
	479	.instance_size = sizeof(VirtIOMMIOProxy),
	480	.class_init = virtio_mmio_class_init,
	481	};
	482
	483	/* virtio-mmio-bus. */
	484
f58b39d2 LE	485	static char virtio_mmio_bus_get_dev_path(DeviceState dev)
	486	{
	487	BusState *virtio_mmio_bus;
	488	VirtIOMMIOProxy *virtio_mmio_proxy;
	489	char *proxy_path;
	490	SysBusDevice *proxy_sbd;
	491	char *path;
	492
	493	virtio_mmio_bus = qdev_get_parent_bus(dev);
	494	virtio_mmio_proxy = VIRTIO_MMIO(virtio_mmio_bus->parent);
	495	proxy_path = qdev_get_dev_path(DEVICE(virtio_mmio_proxy));
	496
	497	/*
	498	* If @format_transport_address is false, then we just perform the same as
	499	* virtio_bus_get_dev_path(): we delegate the address formatting for the
	500	* device on the virtio-mmio bus to the bus that the virtio-mmio proxy
	501	* (i.e., the device that implements the virtio-mmio bus) resides on. In
	502	* this case the base address of the virtio-mmio transport will be
	503	* invisible.
	504	*/
	505	if (!virtio_mmio_proxy->format_transport_address) {
	506	return proxy_path;
	507	}
	508
	509	/* Otherwise, we append the base address of the transport. */
	510	proxy_sbd = SYS_BUS_DEVICE(virtio_mmio_proxy);
	511	assert(proxy_sbd->num_mmio == 1);
	512	assert(proxy_sbd->mmio[0].memory == &virtio_mmio_proxy->iomem);
	513
	514	if (proxy_path) {
	515	path = g_strdup_printf("%s/virtio-mmio@" TARGET_FMT_plx, proxy_path,
	516	proxy_sbd->mmio[0].addr);
	517	} else {
	518	path = g_strdup_printf("virtio-mmio@" TARGET_FMT_plx,
	519	proxy_sbd->mmio[0].addr);
	520	}
	521	g_free(proxy_path);
	522	return path;
	523	}
	524
4b52530b PM	525	static void virtio_mmio_bus_class_init(ObjectClass klass, void data)
	526	{
	527	BusClass *bus_class = BUS_CLASS(klass);
	528	VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
	529
	530	k->notify = virtio_mmio_update_irq;
	531	k->save_config = virtio_mmio_save_config;
	532	k->load_config = virtio_mmio_load_config;
434027ba	533	k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
8e93cef1	534	k->ioeventfd_enabled = virtio_mmio_ioeventfd_enabled;
c0971bcb	535	k->ioeventfd_assign = virtio_mmio_ioeventfd_assign;
4b52530b PM	536	k->has_variable_vring_alignment = true;
4b52530b PM	537	bus_class->max_dev = 1;
f58b39d2	538	bus_class->get_dev_path = virtio_mmio_bus_get_dev_path;
4b52530b PM	539	}
	540
	541	static const TypeInfo virtio_mmio_bus_info = {
	542	.name = TYPE_VIRTIO_MMIO_BUS,
	543	.parent = TYPE_VIRTIO_BUS,
	544	.instance_size = sizeof(VirtioBusState),
	545	.class_init = virtio_mmio_bus_class_init,
	546	};
	547
	548	static void virtio_mmio_register_types(void)
	549	{
	550	type_register_static(&virtio_mmio_bus_info);
	551	type_register_static(&virtio_mmio_info);
	552	}
	553
	554	type_init(virtio_mmio_register_types)