Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1287 commits)
  icmp: Fix regression in nexthop resolution during replies.
  net: Fix ppc64 BPF JIT dependencies.
  acenic: include NET_SKB_PAD headroom to incoming skbs
  ixgbe: convert to ndo_fix_features
  ixgbe: only enable WoL for magic packet by default
  ixgbe: remove ifdef check for non-existent define
  ixgbe: Pass staterr instead of re-reading status and error bits from descriptor
  ixgbe: Move interrupt related values out of ring and into q_vector
  ixgbe: add structure for containing RX/TX rings to q_vector
  ixgbe: inline the ixgbe_maybe_stop_tx function
  ixgbe: Update ATR to use recorded TX queues instead of CPU for routing
  igb: Fix for DH89xxCC near end loopback test
  e1000: always call e1000_check_for_link() on e1000_ce4100 MACs.
  netxen: add fw version compatibility check
  be2net: request native mode each time the card is reset
  ipv4: Constrain UFO fragment sizes to multiples of 8 bytes
  virtio_net: Fix panic in virtnet_remove
  ipv6: make fragment identifications less predictable
  ipv6: unshare inetpeers
  can: make function can_get_bittiming static
  ...

1 files changed, 90 insertions, 1 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index e224a92baa1..882a51fe7b3 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -12,6 +12,7 @@
 #include <linux/virtio_net.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/mutex.h>
 #include <linux/workqueue.h>
 #include <linux/rcupdate.h>
@@ -28,10 +29,18 @@
 
 #include "vhost.h"
 
+static int experimental_zcopytx;
+module_param(experimental_zcopytx, int, 0444);
+MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX");
+
 /* Max number of bytes transferred before requeueing the job.
  * Using this limit prevents one virtqueue from starving others. */
 #define VHOST_NET_WEIGHT 0x80000
 
+/* MAX number of TX used buffers for outstanding zerocopy */
+#define VHOST_MAX_PEND 128
+#define VHOST_GOODCOPY_LEN 256
+
 enum {
 	VHOST_NET_VQ_RX = 0,
 	VHOST_NET_VQ_TX = 1,
@@ -54,6 +63,12 @@ struct vhost_net {
 	enum vhost_net_poll_state tx_poll_state;
 };
 
+static bool vhost_sock_zcopy(struct socket *sock)
+{
+	return unlikely(experimental_zcopytx) &&
+		sock_flag(sock->sk, SOCK_ZEROCOPY);
+}
+
 /* Pop first len bytes from iovec. Return number of segments used. */
 static int move_iovec_hdr(struct iovec *from, struct iovec *to,
 			  size_t len, int iov_count)
@@ -129,6 +144,8 @@ static void handle_tx(struct vhost_net *net)
 	int err, wmem;
 	size_t hdr_size;
 	struct socket *sock;
+	struct vhost_ubuf_ref *uninitialized_var(ubufs);
+	bool zcopy;
 
 	/* TODO: check that we are running from vhost_worker? */
 	sock = rcu_dereference_check(vq->private_data, 1);
@@ -149,8 +166,13 @@ static void handle_tx(struct vhost_net *net)
 	if (wmem < sock->sk->sk_sndbuf / 2)
 		tx_poll_stop(net);
 	hdr_size = vq->vhost_hlen;
+	zcopy = vhost_sock_zcopy(sock);
 
 	for (;;) {
+		/* Release DMAs done buffers first */
+		if (zcopy)
+			vhost_zerocopy_signal_used(vq);
+
 		head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
 					 ARRAY_SIZE(vq->iov),
 					 &out, &in,
@@ -160,12 +182,25 @@ static void handle_tx(struct vhost_net *net)
 			break;
 		/* Nothing new?  Wait for eventfd to tell us they refilled. */
 		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);
+				break;
+			}
 			if (unlikely(vhost_enable_notify(&net->dev, vq))) {
 				vhost_disable_notify(&net->dev, vq);
 				continue;
@@ -188,9 +223,39 @@ static void handle_tx(struct vhost_net *net)
 			       iov_length(vq->hdr, s), hdr_size);
 			break;
 		}
+		/* use msg_control to pass vhost zerocopy ubuf info to skb */
+		if (zcopy) {
+			vq->heads[vq->upend_idx].id = head;
+			if (len < VHOST_GOODCOPY_LEN) {
+				/* copy don't need to wait for DMA done */
+				vq->heads[vq->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];
+
+				vq->heads[vq->upend_idx].len = len;
+				ubuf->callback = vhost_zerocopy_callback;
+				ubuf->arg = vq->ubufs;
+				ubuf->desc = vq->upend_idx;
+				msg.msg_control = ubuf;
+				msg.msg_controllen = sizeof(ubuf);
+				ubufs = vq->ubufs;
+				kref_get(&ubufs->kref);
+			}
+			vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV;
+		}
 		/* TODO: Check specific error and bomb out unless ENOBUFS? */
 		err = sock->ops->sendmsg(NULL, sock, &msg, len);
 		if (unlikely(err < 0)) {
+			if (zcopy) {
+				if (ubufs)
+					vhost_ubuf_put(ubufs);
+				vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
+					UIO_MAXIOV;
+			}
 			vhost_discard_vq_desc(vq, 1);
 			tx_poll_start(net, sock);
 			break;
@@ -198,7 +263,8 @@ static void handle_tx(struct vhost_net *net)
 		if (err != len)
 			pr_debug("Truncated TX packet: "
 				 " len %d != %zd\n", err, len);
-		vhost_add_used_and_signal(&net->dev, vq, head, 0);
+		if (!zcopy)
+			vhost_add_used_and_signal(&net->dev, vq, head, 0);
 		total_len += len;
 		if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
 			vhost_poll_queue(&vq->poll);
@@ -603,6 +669,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 {
 	struct socket *sock, *oldsock;
 	struct vhost_virtqueue *vq;
+	struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
 	int r;
 
 	mutex_lock(&n->dev.mutex);
@@ -632,13 +699,31 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 	oldsock = rcu_dereference_protected(vq->private_data,
 					    lockdep_is_held(&vq->mutex));
 	if (sock != oldsock) {
+		ubufs = vhost_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock));
+		if (IS_ERR(ubufs)) {
+			r = PTR_ERR(ubufs);
+			goto err_ubufs;
+		}
+		oldubufs = vq->ubufs;
+		vq->ubufs = ubufs;
 		vhost_net_disable_vq(n, vq);
 		rcu_assign_pointer(vq->private_data, sock);
 		vhost_net_enable_vq(n, vq);
+
+		r = vhost_init_used(vq);
+		if (r)
+			goto err_vq;
 	}
 
 	mutex_unlock(&vq->mutex);
 
+	if (oldubufs) {
+		vhost_ubuf_put_and_wait(oldubufs);
+		mutex_lock(&vq->mutex);
+		vhost_zerocopy_signal_used(vq);
+		mutex_unlock(&vq->mutex);
+	}
+
 	if (oldsock) {
 		vhost_net_flush_vq(n, index);
 		fput(oldsock->file);
@@ -647,6 +732,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 	mutex_unlock(&n->dev.mutex);
 	return 0;
 
+err_ubufs:
+	fput(sock->file);
 err_vq:
 	mutex_unlock(&vq->mutex);
 err:
@@ -776,6 +863,8 @@ static struct miscdevice vhost_net_misc = {
 
 static int vhost_net_init(void)
 {
+	if (experimental_zcopytx)
+		vhost_enable_zcopy(VHOST_NET_VQ_TX);
 	return misc_register(&vhost_net_misc);
 }
 module_init(vhost_net_init);