Commit 0c87e93e authored by Jason Wang's avatar Jason Wang Committed by Anthony Liguori
Browse files

virtio-net: separate virtqueue from VirtIONet 



To support multiqueue virtio-net, the first step is to separate the virtqueue
related fields from VirtIONet to a new structure VirtIONetQueue. The following
patches will add an array of VirtIONetQueue to VirtIONet based on this patch.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent e78a2b42

hw/virtio-net.c

+114 −81
Original line number Diff line number Diff line
@@ -26,28 +26,33 @@ 
#define MAC_TABLE_ENTRIES    64

#define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */



typedef struct VirtIONetQueue {

    VirtQueue *rx_vq;

    VirtQueue *tx_vq;

    QEMUTimer *tx_timer;

    QEMUBH *tx_bh;

    int tx_waiting;

    struct {

        VirtQueueElement elem;

        ssize_t len;

    } async_tx;

    struct VirtIONet *n;

} VirtIONetQueue;



typedef struct VirtIONet

{

    VirtIODevice vdev;

    uint8_t mac[ETH_ALEN];

    uint16_t status;

    VirtQueue *rx_vq;

    VirtQueue *tx_vq;

    VirtIONetQueue vq;

    VirtQueue *ctrl_vq;

    NICState *nic;

    QEMUTimer *tx_timer;

    QEMUBH *tx_bh;

    uint32_t tx_timeout;

    int32_t tx_burst;

    int tx_waiting;

    uint32_t has_vnet_hdr;

    size_t host_hdr_len;

    size_t guest_hdr_len;

    uint8_t has_ufo;

    struct {

        VirtQueueElement elem;

        ssize_t len;

    } async_tx;

    int mergeable_rx_bufs;

    uint8_t promisc;

    uint8_t allmulti;
@@ -67,6 +72,12 @@ typedef struct VirtIONet 
    DeviceState *qdev;

} VirtIONet;



static VirtIONetQueue *virtio_net_get_queue(NetClientState *nc)

{

    VirtIONet *n = qemu_get_nic_opaque(nc);



    return &n->vq;

}

/* TODO

 * - we could suppress RX interrupt if we were so inclined.

 */
@@ -135,6 +146,8 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status) 
            error_report("unable to start vhost net: %d: "

                         "falling back on userspace virtio", -r);

            n->vhost_started = 0;

        } else {

            n->vhost_started = 1;

        }

    } else {

        vhost_net_stop(&n->vdev, nc, 1);
@@ -145,25 +158,26 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status) 
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)

{

    VirtIONet *n = to_virtio_net(vdev);

    VirtIONetQueue *q = &n->vq;



    virtio_net_vhost_status(n, status);



    if (!n->tx_waiting) {

    if (!q->tx_waiting) {

        return;

    }



    if (virtio_net_started(n, status) && !n->vhost_started) {

        if (n->tx_timer) {

            qemu_mod_timer(n->tx_timer,

        if (q->tx_timer) {

            qemu_mod_timer(q->tx_timer,

                           qemu_get_clock_ns(vm_clock) + n->tx_timeout);

        } else {

            qemu_bh_schedule(n->tx_bh);

            qemu_bh_schedule(q->tx_bh);

        }

    } else {

        if (n->tx_timer) {

            qemu_del_timer(n->tx_timer);

        if (q->tx_timer) {

            qemu_del_timer(q->tx_timer);

        } else {

            qemu_bh_cancel(n->tx_bh);

            qemu_bh_cancel(q->tx_bh);

        }

    }

}
@@ -507,35 +521,40 @@ static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq) 
static int virtio_net_can_receive(NetClientState *nc)

{

    VirtIONet *n = qemu_get_nic_opaque(nc);

    VirtIONetQueue *q = virtio_net_get_queue(nc);



    if (!n->vdev.vm_running) {

        return 0;

    }



    if (!virtio_queue_ready(n->rx_vq) ||

        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))

    if (!virtio_queue_ready(q->rx_vq) ||

        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {

        return 0;

    }



    return 1;

}



static int virtio_net_has_buffers(VirtIONet *n, int bufsize)

static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)

{

    if (virtio_queue_empty(n->rx_vq) ||

    VirtIONet *n = q->n;

    if (virtio_queue_empty(q->rx_vq) ||

        (n->mergeable_rx_bufs &&

         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {

        virtio_queue_set_notification(n->rx_vq, 1);

         !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {

        virtio_queue_set_notification(q->rx_vq, 1);



        /* To avoid a race condition where the guest has made some buffers

         * available after the above check but before notification was

         * enabled, check for available buffers again.

         */

        if (virtio_queue_empty(n->rx_vq) ||

        if (virtio_queue_empty(q->rx_vq) ||

            (n->mergeable_rx_bufs &&

             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))

             !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {

            return 0;

        }

    }



    virtio_queue_set_notification(n->rx_vq, 0);

    virtio_queue_set_notification(q->rx_vq, 0);

    return 1;

}
@@ -638,6 +657,7 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size) 
static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t size)

{

    VirtIONet *n = qemu_get_nic_opaque(nc);

    VirtIONetQueue *q = virtio_net_get_queue(nc);

    struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];

    struct virtio_net_hdr_mrg_rxbuf mhdr;

    unsigned mhdr_cnt = 0;
@@ -648,8 +668,9 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t 
    }



    /* hdr_len refers to the header we supply to the guest */

    if (!virtio_net_has_buffers(n, size + n->guest_hdr_len - n->host_hdr_len))

    if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {

        return 0;

    }



    if (!receive_filter(n, buf, size))

        return size;
@@ -663,7 +684,7 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t 


        total = 0;



        if (virtqueue_pop(n->rx_vq, &elem) == 0) {

        if (virtqueue_pop(q->rx_vq, &elem) == 0) {

            if (i == 0)

                return -1;

            error_report("virtio-net unexpected empty queue: "
@@ -716,7 +737,7 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t 
        }



        /* signal other side */

        virtqueue_fill(n->rx_vq, &elem, total, i++);

        virtqueue_fill(q->rx_vq, &elem, total, i++);

    }



    if (mhdr_cnt) {
@@ -726,30 +747,32 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t 
                     &mhdr.num_buffers, sizeof mhdr.num_buffers);

    }



    virtqueue_flush(n->rx_vq, i);

    virtio_notify(&n->vdev, n->rx_vq);

    virtqueue_flush(q->rx_vq, i);

    virtio_notify(&n->vdev, q->rx_vq);



    return size;

}



static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);

static int32_t virtio_net_flush_tx(VirtIONetQueue *q);



static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)

{

    VirtIONet *n = qemu_get_nic_opaque(nc);

    VirtIONetQueue *q = virtio_net_get_queue(nc);



    virtqueue_push(n->tx_vq, &n->async_tx.elem, 0);

    virtio_notify(&n->vdev, n->tx_vq);

    virtqueue_push(q->tx_vq, &q->async_tx.elem, 0);

    virtio_notify(&n->vdev, q->tx_vq);



    n->async_tx.elem.out_num = n->async_tx.len = 0;

    q->async_tx.elem.out_num = q->async_tx.len = 0;



    virtio_queue_set_notification(n->tx_vq, 1);

    virtio_net_flush_tx(n, n->tx_vq);

    virtio_queue_set_notification(q->tx_vq, 1);

    virtio_net_flush_tx(q);

}



/* TX */

static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)

static int32_t virtio_net_flush_tx(VirtIONetQueue *q)

{

    VirtIONet *n = q->n;

    VirtQueueElement elem;

    int32_t num_packets = 0;

    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
@@ -758,12 +781,12 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq) 


    assert(n->vdev.vm_running);



    if (n->async_tx.elem.out_num) {

        virtio_queue_set_notification(n->tx_vq, 0);

    if (q->async_tx.elem.out_num) {

        virtio_queue_set_notification(q->tx_vq, 0);

        return num_packets;

    }



    while (virtqueue_pop(vq, &elem)) {

    while (virtqueue_pop(q->tx_vq, &elem)) {

        ssize_t ret, len;

        unsigned int out_num = elem.out_num;

        struct iovec *out_sg = &elem.out_sg[0];
@@ -796,16 +819,16 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq) 
        ret = qemu_sendv_packet_async(qemu_get_queue(n->nic), out_sg, out_num,

                                      virtio_net_tx_complete);

        if (ret == 0) {

            virtio_queue_set_notification(n->tx_vq, 0);

            n->async_tx.elem = elem;

            n->async_tx.len  = len;

            virtio_queue_set_notification(q->tx_vq, 0);

            q->async_tx.elem = elem;

            q->async_tx.len  = len;

            return -EBUSY;

        }



        len += ret;



        virtqueue_push(vq, &elem, 0);

        virtio_notify(&n->vdev, vq);

        virtqueue_push(q->tx_vq, &elem, 0);

        virtio_notify(&n->vdev, q->tx_vq);



        if (++num_packets >= n->tx_burst) {

            break;
@@ -817,22 +840,23 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq) 
static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)

{

    VirtIONet *n = to_virtio_net(vdev);

    VirtIONetQueue *q = &n->vq;



    /* This happens when device was stopped but VCPU wasn't. */

    if (!n->vdev.vm_running) {

        n->tx_waiting = 1;

        q->tx_waiting = 1;

        return;

    }



    if (n->tx_waiting) {

    if (q->tx_waiting) {

        virtio_queue_set_notification(vq, 1);

        qemu_del_timer(n->tx_timer);

        n->tx_waiting = 0;

        virtio_net_flush_tx(n, vq);

        qemu_del_timer(q->tx_timer);

        q->tx_waiting = 0;

        virtio_net_flush_tx(q);

    } else {

        qemu_mod_timer(n->tx_timer,

        qemu_mod_timer(q->tx_timer,

                       qemu_get_clock_ns(vm_clock) + n->tx_timeout);

        n->tx_waiting = 1;

        q->tx_waiting = 1;

        virtio_queue_set_notification(vq, 0);

    }

}
@@ -840,48 +864,51 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq) 
static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)

{

    VirtIONet *n = to_virtio_net(vdev);

    VirtIONetQueue *q = &n->vq;



    if (unlikely(n->tx_waiting)) {

    if (unlikely(q->tx_waiting)) {

        return;

    }

    n->tx_waiting = 1;

    q->tx_waiting = 1;

    /* This happens when device was stopped but VCPU wasn't. */

    if (!n->vdev.vm_running) {

        return;

    }

    virtio_queue_set_notification(vq, 0);

    qemu_bh_schedule(n->tx_bh);

    qemu_bh_schedule(q->tx_bh);

}



static void virtio_net_tx_timer(void *opaque)

{

    VirtIONet *n = opaque;

    VirtIONetQueue *q = opaque;

    VirtIONet *n = q->n;

    assert(n->vdev.vm_running);



    n->tx_waiting = 0;

    q->tx_waiting = 0;



    /* Just in case the driver is not ready on more */

    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))

        return;



    virtio_queue_set_notification(n->tx_vq, 1);

    virtio_net_flush_tx(n, n->tx_vq);

    virtio_queue_set_notification(q->tx_vq, 1);

    virtio_net_flush_tx(q);

}



static void virtio_net_tx_bh(void *opaque)

{

    VirtIONet *n = opaque;

    VirtIONetQueue *q = opaque;

    VirtIONet *n = q->n;

    int32_t ret;



    assert(n->vdev.vm_running);



    n->tx_waiting = 0;

    q->tx_waiting = 0;



    /* Just in case the driver is not ready on more */

    if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))

        return;



    ret = virtio_net_flush_tx(n, n->tx_vq);

    ret = virtio_net_flush_tx(q);

    if (ret == -EBUSY) {

        return; /* Notification re-enable handled by tx_complete */

    }
@@ -889,25 +916,26 @@ static void virtio_net_tx_bh(void *opaque) 
    /* If we flush a full burst of packets, assume there are

     * more coming and immediately reschedule */

    if (ret >= n->tx_burst) {

        qemu_bh_schedule(n->tx_bh);

        n->tx_waiting = 1;

        qemu_bh_schedule(q->tx_bh);

        q->tx_waiting = 1;

        return;

    }



    /* If less than a full burst, re-enable notification and flush

     * anything that may have come in while we weren't looking.  If

     * we find something, assume the guest is still active and reschedule */

    virtio_queue_set_notification(n->tx_vq, 1);

    if (virtio_net_flush_tx(n, n->tx_vq) > 0) {

        virtio_queue_set_notification(n->tx_vq, 0);

        qemu_bh_schedule(n->tx_bh);

        n->tx_waiting = 1;

    virtio_queue_set_notification(q->tx_vq, 1);

    if (virtio_net_flush_tx(q) > 0) {

        virtio_queue_set_notification(q->tx_vq, 0);

        qemu_bh_schedule(q->tx_bh);

        q->tx_waiting = 1;

    }

}



static void virtio_net_save(QEMUFile *f, void *opaque)

{

    VirtIONet *n = opaque;

    VirtIONetQueue *q = &n->vq;



    /* At this point, backend must be stopped, otherwise

     * it might keep writing to memory. */
@@ -915,7 +943,7 @@ static void virtio_net_save(QEMUFile *f, void *opaque) 
    virtio_save(&n->vdev, f);



    qemu_put_buffer(f, n->mac, ETH_ALEN);

    qemu_put_be32(f, n->tx_waiting);

    qemu_put_be32(f, q->tx_waiting);

    qemu_put_be32(f, n->mergeable_rx_bufs);

    qemu_put_be16(f, n->status);

    qemu_put_byte(f, n->promisc);
@@ -936,6 +964,7 @@ static void virtio_net_save(QEMUFile *f, void *opaque) 
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)

{

    VirtIONet *n = opaque;

    VirtIONetQueue *q = &n->vq;

    int i;

    int ret;
@@ -948,7 +977,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id) 
    }



    qemu_get_buffer(f, n->mac, ETH_ALEN);

    n->tx_waiting = qemu_get_be32(f);

    q->tx_waiting = qemu_get_be32(f);



    virtio_net_set_mrg_rx_bufs(n, qemu_get_be32(f));
@@ -1085,7 +1114,8 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf, 
    n->vdev.set_status = virtio_net_set_status;

    n->vdev.guest_notifier_mask = virtio_net_guest_notifier_mask;

    n->vdev.guest_notifier_pending = virtio_net_guest_notifier_pending;

    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);

    n->vq.rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);

    n->vq.n = n;



    if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {

        error_report("virtio-net: "
@@ -1095,12 +1125,14 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf, 
    }



    if (net->tx && !strcmp(net->tx, "timer")) {

        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);

        n->tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer, n);

        n->vq.tx_vq = virtio_add_queue(&n->vdev, 256,

                                       virtio_net_handle_tx_timer);

        n->vq.tx_timer = qemu_new_timer_ns(vm_clock,

                                           virtio_net_tx_timer, &n->vq);

        n->tx_timeout = net->txtimer;

    } else {

        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);

        n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);

        n->vq.tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);

        n->vq.tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vq);

    }

    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);

    qemu_macaddr_default_if_unset(&conf->macaddr);
@@ -1118,7 +1150,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf, 


    qemu_format_nic_info_str(qemu_get_queue(n->nic), conf->macaddr.a);



    n->tx_waiting = 0;

    n->vq.tx_waiting = 0;

    n->tx_burst = net->txburst;

    virtio_net_set_mrg_rx_bufs(n, 0);

    n->promisc = 1; /* for compatibility */
@@ -1139,6 +1171,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf, 
void virtio_net_exit(VirtIODevice *vdev)

{

    VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);

    VirtIONetQueue *q = &n->vq;



    /* This will stop vhost backend if appropriate. */

    virtio_net_set_status(vdev, 0);
@@ -1150,11 +1183,11 @@ void virtio_net_exit(VirtIODevice *vdev) 
    g_free(n->mac_table.macs);

    g_free(n->vlans);



    if (n->tx_timer) {

        qemu_del_timer(n->tx_timer);

        qemu_free_timer(n->tx_timer);

    if (q->tx_timer) {

        qemu_del_timer(q->tx_timer);

        qemu_free_timer(q->tx_timer);

    } else {

        qemu_bh_delete(n->tx_bh);

        qemu_bh_delete(q->tx_bh);

    }



    qemu_del_nic(n->nic);