1 files changed, 207 insertions, 115 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 959b1cd89e6a..a3645bd163d8 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -64,20 +64,36 @@ enum {
         VHOST_NET_VQ_MAX = 2,
 };
 
-enum vhost_net_poll_state {
-        VHOST_NET_POLL_DISABLED = 0,
-        VHOST_NET_POLL_STARTED = 1,
-        VHOST_NET_POLL_STOPPED = 2,
+struct vhost_ubuf_ref {
+        struct kref kref;
+        wait_queue_head_t wait;
+        struct vhost_virtqueue *vq;
+};
+
+struct vhost_net_virtqueue {
+        struct vhost_virtqueue vq;
+        /* hdr is used to store the virtio header.
+         * Since each iovec has >= 1 byte length, we never need more than
+         * header length entries to store the header. */
+        struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
+        size_t vhost_hlen;
+        size_t sock_hlen;
+        /* vhost zerocopy support fields below: */
+        /* last used idx for outstanding DMA zerocopy buffers */
+        int upend_idx;
+        /* first used idx for DMA done zerocopy buffers */
+        int done_idx;
+        /* an array of userspace buffers info */
+        struct ubuf_info *ubuf_info;
+        /* Reference counting for outstanding ubufs.
+         * Protected by vq mutex. Writers must also take device mutex. */
+        struct vhost_ubuf_ref *ubufs;
 };
 
 struct vhost_net {
         struct vhost_dev dev;
-        struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
+        struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX];
         struct vhost_poll poll[VHOST_NET_VQ_MAX];
-        /* Tells us whether we are polling a socket for TX.
-         * We only do this when socket buffer fills up.
-         * Protected by tx vq lock. */
-        enum vhost_net_poll_state tx_poll_state;
         /* Number of TX recently submitted.
          * Protected by tx vq lock. */
         unsigned tx_packets;
@@ -88,6 +104,90 @@ struct vhost_net {
         bool tx_flush;
 };
 
+static unsigned vhost_zcopy_mask __read_mostly;
+
+void vhost_enable_zcopy(int vq)
+{
+        vhost_zcopy_mask |= 0x1 << vq;
+}
+
+static void vhost_zerocopy_done_signal(struct kref *kref)
+{
+        struct vhost_ubuf_ref *ubufs = container_of(kref, struct vhost_ubuf_ref,
+                                                    kref);
+        wake_up(&ubufs->wait);
+}
+
+struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *vq,
+                                        bool zcopy)
+{
+        struct vhost_ubuf_ref *ubufs;
+        /* No zero copy backend? Nothing to count. */
+        if (!zcopy)
+                return NULL;
+        ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL);
+        if (!ubufs)
+                return ERR_PTR(-ENOMEM);
+        kref_init(&ubufs->kref);
+        init_waitqueue_head(&ubufs->wait);
+        ubufs->vq = vq;
+        return ubufs;
+}
+
+void vhost_ubuf_put(struct vhost_ubuf_ref *ubufs)
+{
+        kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
+}
+
+void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *ubufs)
+{
+        kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
+        wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount));
+        kfree(ubufs);
+}
+
+int vhost_net_set_ubuf_info(struct vhost_net *n)
+{
+        bool zcopy;
+        int i;
+
+        for (i = 0; i < n->dev.nvqs; ++i) {
+                zcopy = vhost_zcopy_mask & (0x1 << i);
+                if (!zcopy)
+                        continue;
+                n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
+                                              UIO_MAXIOV, GFP_KERNEL);
+                if  (!n->vqs[i].ubuf_info)
+                        goto err;
+        }
+        return 0;
+
+err:
+        while (i--) {
+                zcopy = vhost_zcopy_mask & (0x1 << i);
+                if (!zcopy)
+                        continue;
+                kfree(n->vqs[i].ubuf_info);
+        }
+        return -ENOMEM;
+}
+
+void vhost_net_vq_reset(struct vhost_net *n)
+{
+        int i;
+
+        for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
+                n->vqs[i].done_idx = 0;
+                n->vqs[i].upend_idx = 0;
+                n->vqs[i].ubufs = NULL;
+                kfree(n->vqs[i].ubuf_info);
+                n->vqs[i].ubuf_info = NULL;
+                n->vqs[i].vhost_hlen = 0;
+                n->vqs[i].sock_hlen = 0;
+        }
+
+}
+
 static void vhost_net_tx_packet(struct vhost_net *net)
 {
         ++net->tx_packets;
@@ -155,28 +255,6 @@ static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
         }
 }
 
-/* Caller must have TX VQ lock */
-static void tx_poll_stop(struct vhost_net *net)
-{
-        if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED))
-                return;
-        vhost_poll_stop(net->poll + VHOST_NET_VQ_TX);
-        net->tx_poll_state = VHOST_NET_POLL_STOPPED;
-}
-
-/* Caller must have TX VQ lock */
-static int tx_poll_start(struct vhost_net *net, struct socket *sock)
-{
-        int ret;
-
-        if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED))
-                return 0;
-        ret = vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file);
-        if (!ret)
-                net->tx_poll_state = VHOST_NET_POLL_STARTED;
-        return ret;
-}
-
 /* In case of DMA done not in order in lower device driver for some reason.
  * upend_idx is used to track end of used idx, done_idx is used to track head
  * of used idx. Once lower device DMA done contiguously, we will signal KVM
@@ -185,10 +263,12 @@ static int tx_poll_start(struct vhost_net *net, struct socket *sock)
 static int vhost_zerocopy_signal_used(struct vhost_net *net,
                                       struct vhost_virtqueue *vq)
 {
+        struct vhost_net_virtqueue *nvq =
+                container_of(vq, struct vhost_net_virtqueue, vq);
         int i;
         int j = 0;
 
-        for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
+        for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
                 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN)
                         vhost_net_tx_err(net);
                 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
@@ -200,7 +280,7 @@ static int vhost_zerocopy_signal_used(struct vhost_net *net,
                         break;
         }
         if (j)
-                vq->done_idx = i;
+                nvq->done_idx = i;
         return j;
 }
 
@@ -230,7 +310,8 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success)
  * read-size critical section for our kind of RCU. */
 static void handle_tx(struct vhost_net *net)
 {
-        struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
+        struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
+        struct vhost_virtqueue *vq = &nvq->vq;
         unsigned out, in, s;
         int head;
         struct msghdr msg = {
@@ -242,7 +323,7 @@ static void handle_tx(struct vhost_net *net)
                 .msg_flags = MSG_DONTWAIT,
         };
         size_t len, total_len = 0;
-        int err, wmem;
+        int err;
         size_t hdr_size;
         struct socket *sock;
         struct vhost_ubuf_ref *uninitialized_var(ubufs);
@@ -253,21 +334,11 @@ static void handle_tx(struct vhost_net *net)
         if (!sock)
                 return;
 
-        wmem = atomic_read(&sock->sk->sk_wmem_alloc);
-        if (wmem >= sock->sk->sk_sndbuf) {
-                mutex_lock(&vq->mutex);
-                tx_poll_start(net, sock);
-                mutex_unlock(&vq->mutex);
-                return;
-        }
-
         mutex_lock(&vq->mutex);
         vhost_disable_notify(&net->dev, vq);
 
-        if (wmem < sock->sk->sk_sndbuf / 2)
-                tx_poll_stop(net);
-        hdr_size = vq->vhost_hlen;
-        zcopy = vq->ubufs;
+        hdr_size = nvq->vhost_hlen;
+        zcopy = nvq->ubufs;
 
         for (;;) {
                 /* Release DMAs done buffers first */
@@ -285,23 +356,15 @@ static void handle_tx(struct vhost_net *net)
                 if (head == vq->num) {
                         int num_pends;
 
-                        wmem = atomic_read(&sock->sk->sk_wmem_alloc);
-                        if (wmem >= sock->sk->sk_sndbuf * 3 / 4) {
-                                tx_poll_start(net, sock);
-                                set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
-                                break;
-                        }
                         /* If more outstanding DMAs, queue the work.
                          * Handle upend_idx wrap around
                          */
-                        num_pends = likely(vq->upend_idx >= vq->done_idx) ?
-                                    (vq->upend_idx - vq->done_idx) :
-                                    (vq->upend_idx + UIO_MAXIOV - vq->done_idx);
-                        if (unlikely(num_pends > VHOST_MAX_PEND)) {
-                                tx_poll_start(net, sock);
-                                set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
+                        num_pends = likely(nvq->upend_idx >= nvq->done_idx) ?
+                                    (nvq->upend_idx - nvq->done_idx) :
+                                    (nvq->upend_idx + UIO_MAXIOV -
+                                     nvq->done_idx);
+                        if (unlikely(num_pends > VHOST_MAX_PEND))
                                 break;
-                        }
                         if (unlikely(vhost_enable_notify(&net->dev, vq))) {
                                 vhost_disable_notify(&net->dev, vq);
                                 continue;
@@ -314,44 +377,45 @@ static void handle_tx(struct vhost_net *net)
                         break;
                 }
                 /* Skip header. TODO: support TSO. */
-                s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
+                s = move_iovec_hdr(vq->iov, nvq->hdr, hdr_size, out);
                 msg.msg_iovlen = out;
                 len = iov_length(vq->iov, out);
                 /* Sanity check */
                 if (!len) {
                         vq_err(vq, "Unexpected header len for TX: "
                                "%zd expected %zd\n",
-                               iov_length(vq->hdr, s), hdr_size);
+                               iov_length(nvq->hdr, s), hdr_size);
                         break;
                 }
                 zcopy_used = zcopy && (len >= VHOST_GOODCOPY_LEN ||
-                                       vq->upend_idx != vq->done_idx);
+                                       nvq->upend_idx != nvq->done_idx);
 
                 /* use msg_control to pass vhost zerocopy ubuf info to skb */
                 if (zcopy_used) {
-                        vq->heads[vq->upend_idx].id = head;
+                        vq->heads[nvq->upend_idx].id = head;
                         if (!vhost_net_tx_select_zcopy(net) ||
                             len < VHOST_GOODCOPY_LEN) {
                                 /* copy don't need to wait for DMA done */
-                                vq->heads[vq->upend_idx].len =
+                                vq->heads[nvq->upend_idx].len =
                                                         VHOST_DMA_DONE_LEN;
                                 msg.msg_control = NULL;
                                 msg.msg_controllen = 0;
                                 ubufs = NULL;
                         } else {
-                                struct ubuf_info *ubuf = &vq->ubuf_info[head];
+                                struct ubuf_info *ubuf;
+                                ubuf = nvq->ubuf_info + nvq->upend_idx;
 
-                                vq->heads[vq->upend_idx].len =
+                                vq->heads[nvq->upend_idx].len =
                                         VHOST_DMA_IN_PROGRESS;
                                 ubuf->callback = vhost_zerocopy_callback;
-                                ubuf->ctx = vq->ubufs;
-                                ubuf->desc = vq->upend_idx;
+                                ubuf->ctx = nvq->ubufs;
+                                ubuf->desc = nvq->upend_idx;
                                 msg.msg_control = ubuf;
                                 msg.msg_controllen = sizeof(ubuf);
-                                ubufs = vq->ubufs;
+                                ubufs = nvq->ubufs;
                                 kref_get(&ubufs->kref);
                         }
-                        vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV;
+                        nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
                 }
                 /* TODO: Check specific error and bomb out unless ENOBUFS? */
                 err = sock->ops->sendmsg(NULL, sock, &msg, len);
@@ -359,12 +423,10 @@ static void handle_tx(struct vhost_net *net)
                         if (zcopy_used) {
                                 if (ubufs)
                                         vhost_ubuf_put(ubufs);
-                                vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
-                                        UIO_MAXIOV;
+                                nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
+                                        % UIO_MAXIOV;
                         }
                         vhost_discard_vq_desc(vq, 1);
-                        if (err == -EAGAIN || err == -ENOBUFS)
-                                tx_poll_start(net, sock);
                         break;
                 }
                 if (err != len)
@@ -469,7 +531,8 @@ err:
  * read-size critical section for our kind of RCU. */
 static void handle_rx(struct vhost_net *net)
 {
-        struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
+        struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
+        struct vhost_virtqueue *vq = &nvq->vq;
         unsigned uninitialized_var(in), log;
         struct vhost_log *vq_log;
         struct msghdr msg = {
@@ -497,8 +560,8 @@ static void handle_rx(struct vhost_net *net)
 
         mutex_lock(&vq->mutex);
         vhost_disable_notify(&net->dev, vq);
-        vhost_hlen = vq->vhost_hlen;
-        sock_hlen = vq->sock_hlen;
+        vhost_hlen = nvq->vhost_hlen;
+        sock_hlen = nvq->sock_hlen;
 
         vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
                 vq->log : NULL;
@@ -528,11 +591,11 @@ static void handle_rx(struct vhost_net *net)
                 /* We don't need to be notified again. */
                 if (unlikely((vhost_hlen)))
                         /* Skip header. TODO: support TSO. */
-                        move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
+                        move_iovec_hdr(vq->iov, nvq->hdr, vhost_hlen, in);
                 else
                         /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
                          * needed because recvmsg can modify msg_iov. */
-                        copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
+                        copy_iovec_hdr(vq->iov, nvq->hdr, sock_hlen, in);
                 msg.msg_iovlen = in;
                 err = sock->ops->recvmsg(NULL, sock, &msg,
                                          sock_len, MSG_DONTWAIT | MSG_TRUNC);
@@ -546,7 +609,7 @@ static void handle_rx(struct vhost_net *net)
                         continue;
                 }
                 if (unlikely(vhost_hlen) &&
-                    memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
+                    memcpy_toiovecend(nvq->hdr, (unsigned char *)&hdr, 0,
                                       vhost_hlen)) {
                         vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
                                vq->iov->iov_base);
@@ -554,7 +617,7 @@ static void handle_rx(struct vhost_net *net)
                 }
                 /* TODO: Should check and handle checksum. */
                 if (likely(mergeable) &&
-                    memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
+                    memcpy_toiovecend(nvq->hdr, (unsigned char *)&headcount,
                                       offsetof(typeof(hdr), num_buffers),
                                       sizeof hdr.num_buffers)) {
                         vq_err(vq, "Failed num_buffers write");
@@ -611,23 +674,39 @@ static int vhost_net_open(struct inode *inode, struct file *f)
 {
         struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
         struct vhost_dev *dev;
-        int r;
+        struct vhost_virtqueue **vqs;
+        int r, i;
 
         if (!n)
                 return -ENOMEM;
+        vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
+        if (!vqs) {
+                kfree(n);
+                return -ENOMEM;
+        }
 
         dev = &n->dev;
-        n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
-        n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
-        r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
+        vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
+        vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
+        n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick;
+        n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick;
+        for (i = 0; i < VHOST_NET_VQ_MAX; i++) {
+                n->vqs[i].ubufs = NULL;
+                n->vqs[i].ubuf_info = NULL;
+                n->vqs[i].upend_idx = 0;
+                n->vqs[i].done_idx = 0;
+                n->vqs[i].vhost_hlen = 0;
+                n->vqs[i].sock_hlen = 0;
+        }
+        r = vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
         if (r < 0) {
                 kfree(n);
+                kfree(vqs);
                 return r;
         }
 
         vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
         vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
-        n->tx_poll_state = VHOST_NET_POLL_DISABLED;
 
         f->private_data = n;
 
@@ -637,32 +716,28 @@ static int vhost_net_open(struct inode *inode, struct file *f)
 static void vhost_net_disable_vq(struct vhost_net *n,
                                  struct vhost_virtqueue *vq)
 {
+        struct vhost_net_virtqueue *nvq =
+                container_of(vq, struct vhost_net_virtqueue, vq);
+        struct vhost_poll *poll = n->poll + (nvq - n->vqs);
         if (!vq->private_data)
                 return;
-        if (vq == n->vqs + VHOST_NET_VQ_TX) {
-                tx_poll_stop(n);
-                n->tx_poll_state = VHOST_NET_POLL_DISABLED;
-        } else
-                vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
+        vhost_poll_stop(poll);
 }
 
 static int vhost_net_enable_vq(struct vhost_net *n,
                                 struct vhost_virtqueue *vq)
 {
+        struct vhost_net_virtqueue *nvq =
+                container_of(vq, struct vhost_net_virtqueue, vq);
+        struct vhost_poll *poll = n->poll + (nvq - n->vqs);
         struct socket *sock;
-        int ret;
 
         sock = rcu_dereference_protected(vq->private_data,
                                          lockdep_is_held(&vq->mutex));
         if (!sock)
                 return 0;
-        if (vq == n->vqs + VHOST_NET_VQ_TX) {
-                n->tx_poll_state = VHOST_NET_POLL_STOPPED;
-                ret = tx_poll_start(n, sock);
-        } else
-                ret = vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
 
-        return ret;
+        return vhost_poll_start(poll, sock->file);
 }
 
 static struct socket *vhost_net_stop_vq(struct vhost_net *n,
@@ -682,30 +757,30 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
                            struct socket **rx_sock)
 {
-        *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
-        *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
+        *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq);
+        *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
 }
 
 static void vhost_net_flush_vq(struct vhost_net *n, int index)
 {
         vhost_poll_flush(n->poll + index);
-        vhost_poll_flush(&n->dev.vqs[index].poll);
+        vhost_poll_flush(&n->vqs[index].vq.poll);
 }
 
 static void vhost_net_flush(struct vhost_net *n)
 {
         vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
         vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
-        if (n->dev.vqs[VHOST_NET_VQ_TX].ubufs) {
-                mutex_lock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+        if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
+                mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
                 n->tx_flush = true;
-                mutex_unlock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+                mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
                 /* Wait for all lower device DMAs done. */
-                vhost_ubuf_put_and_wait(n->dev.vqs[VHOST_NET_VQ_TX].ubufs);
-                mutex_lock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+                vhost_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs);
+                mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
                 n->tx_flush = false;
-                kref_init(&n->dev.vqs[VHOST_NET_VQ_TX].ubufs->kref);
-                mutex_unlock(&n->dev.vqs[VHOST_NET_VQ_TX].mutex);
+                kref_init(&n->vqs[VHOST_NET_VQ_TX].ubufs->kref);
+                mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
         }
 }
 
@@ -719,6 +794,7 @@ static int vhost_net_release(struct inode *inode, struct file *f)
         vhost_net_flush(n);
         vhost_dev_stop(&n->dev);
         vhost_dev_cleanup(&n->dev, false);
+        vhost_net_vq_reset(n);
         if (tx_sock)
                 fput(tx_sock->file);
         if (rx_sock)
@@ -726,6 +802,7 @@ static int vhost_net_release(struct inode *inode, struct file *f)
         /* We do an extra flush before freeing memory,
          * since jobs can re-queue themselves. */
         vhost_net_flush(n);
+        kfree(n->dev.vqs);
         kfree(n);
         return 0;
 }
@@ -799,6 +876,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 {
         struct socket *sock, *oldsock;
         struct vhost_virtqueue *vq;
+        struct vhost_net_virtqueue *nvq;
         struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
         int r;
 
@@ -811,7 +889,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
                 r = -ENOBUFS;
                 goto err;
         }
-        vq = n->vqs + index;
+        vq = &n->vqs[index].vq;
+        nvq = &n->vqs[index];
         mutex_lock(&vq->mutex);
 
         /* Verify that ring has been setup correctly. */
@@ -844,8 +923,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
                 if (r)
                         goto err_used;
 
-                oldubufs = vq->ubufs;
-                vq->ubufs = ubufs;
+                oldubufs = nvq->ubufs;
+                nvq->ubufs = ubufs;
 
                 n->tx_packets = 0;
                 n->tx_zcopy_err = 0;
@@ -888,14 +967,21 @@ static long vhost_net_reset_owner(struct vhost_net *n)
         struct socket *tx_sock = NULL;
         struct socket *rx_sock = NULL;
         long err;
+        struct vhost_memory *memory;
 
         mutex_lock(&n->dev.mutex);
         err = vhost_dev_check_owner(&n->dev);
         if (err)
                 goto done;
+        memory = vhost_dev_reset_owner_prepare();
+        if (!memory) {
+                err = -ENOMEM;
+                goto done;
+        }
         vhost_net_stop(n, &tx_sock, &rx_sock);
         vhost_net_flush(n);
-        err = vhost_dev_reset_owner(&n->dev);
+        vhost_dev_reset_owner(&n->dev, memory);
+        vhost_net_vq_reset(n);
 done:
         mutex_unlock(&n->dev.mutex);
         if (tx_sock)
@@ -931,10 +1017,10 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
         n->dev.acked_features = features;
         smp_wmb();
         for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
-                mutex_lock(&n->vqs[i].mutex);
+                mutex_lock(&n->vqs[i].vq.mutex);
                 n->vqs[i].vhost_hlen = vhost_hlen;
                 n->vqs[i].sock_hlen = sock_hlen;
-                mutex_unlock(&n->vqs[i].mutex);
+                mutex_unlock(&n->vqs[i].vq.mutex);
         }
         vhost_net_flush(n);
         mutex_unlock(&n->dev.mutex);
@@ -971,11 +1057,17 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
                 return vhost_net_reset_owner(n);
         default:
                 mutex_lock(&n->dev.mutex);
+                if (ioctl == VHOST_SET_OWNER) {
+                        r = vhost_net_set_ubuf_info(n);
+                        if (r)
+                                goto out;
+                }
                 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
                 if (r == -ENOIOCTLCMD)
                         r = vhost_vring_ioctl(&n->dev, ioctl, argp);
                 else
                         vhost_net_flush(n);
+out:
                 mutex_unlock(&n->dev.mutex);
                 return r;
         }