vhost: move -net specific code out
Zerocopy handling code is vhost-net specific.
Move it from vhost.c/vhost.h out to net.c
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index f80ae5f..532fc88 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -126,6 +126,42 @@
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)
@@ -594,9 +630,18 @@
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);