vhost: move -net specific code out

[~andy/linux] / drivers / vhost / net.c

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 072cbbadbc3683ef75fd6ff2420e40463b8f722e..532fc8830c428ad4afd70ae889176cd574dfdd5b 100644 (file)
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -126,6 +126,42 @@ static void tx_poll_start(struct vhost_net *net, struct socket *sock)
        net->tx_poll_state = VHOST_NET_POLL_STARTED;
 }
 
+/* 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
+ * guest used idx.
+ */
+int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq)
+{
+       int i;
+       int j = 0;
+
+       for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
+               if (VHOST_DMA_IS_DONE(vq->heads[i].len)) {
+                       vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
+                       vhost_add_used_and_signal(vq->dev, vq,
+                                                 vq->heads[i].id, 0);
+                       ++j;
+               } else
+                       break;
+       }
+       if (j)
+               vq->done_idx = i;
+       return j;
+}
+
+static void vhost_zerocopy_callback(struct ubuf_info *ubuf, int status)
+{
+       struct vhost_ubuf_ref *ubufs = ubuf->ctx;
+       struct vhost_virtqueue *vq = ubufs->vq;
+
+       vhost_poll_queue(&vq->poll);
+       /* set len to mark this desc buffers done DMA */
+       vq->heads[ubuf->desc].len = status ?
+               VHOST_DMA_FAILED_LEN : VHOST_DMA_DONE_LEN;
+       vhost_ubuf_put(ubufs);
+}
+
 /* Expects to be always run from workqueue - which acts as
  * read-size critical section for our kind of RCU. */
 static void handle_tx(struct vhost_net *net)
@@ -237,7 +273,8 @@ static void handle_tx(struct vhost_net *net)
                        } else {
                                struct ubuf_info *ubuf = &vq->ubuf_info[head];
 
-                               vq->heads[vq->upend_idx].len = len;
+                               vq->heads[vq->upend_idx].len =
+                                       VHOST_DMA_IN_PROGRESS;
                                ubuf->callback = vhost_zerocopy_callback;
                                ubuf->ctx = vq->ubufs;
                                ubuf->desc = vq->upend_idx;
@@ -593,9 +630,18 @@ static int vhost_net_release(struct inode *inode, struct file *f)
        struct vhost_net *n = f->private_data;
        struct socket *tx_sock;
        struct socket *rx_sock;
+       int i;
 
        vhost_net_stop(n, &tx_sock, &rx_sock);
        vhost_net_flush(n);
+       vhost_dev_stop(&n->dev);
+       for (i = 0; i < n->dev.nvqs; ++i) {
+               /* Wait for all lower device DMAs done. */
+               if (n->dev.vqs[i].ubufs)
+                       vhost_ubuf_put_and_wait(n->dev.vqs[i].ubufs);
+
+               vhost_zerocopy_signal_used(n, &n->dev.vqs[i]);
+       }
        vhost_dev_cleanup(&n->dev, false);
        if (tx_sock)
                fput(tx_sock->file);