Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull vhost cleanups and fixes from Michael Tsirkin:
 "Here are vhost cleanups and fixes by Asias He and myself.  They affect
  both vhost-net and vhost-scsi devices.  They also *depend* on both
  net-next and target-pending, where the net and target commits these
  changes depend on are already merged.  So merging through the common
  vhost tree."

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost_scsi: module rename
  tcm_vhost: header split up
  vhost: src file renames
  vhost: fix error handling in RESET_OWNER ioctl
  tcm_vhost: remove virtio-net.h dependency
  vhost: move per-vq net specific fields out to net
  tcm_vhost: document inflight ref-counting use
  vhost: move vhost-net zerocopy fields to net.c
  tcm_vhost: Wait for pending requests in vhost_scsi_flush()
  vhost: Allow device specific fields per vq

1 files changed, 204 insertions, 51 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 87c216c1e54e..a3645bd163d8 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -64,9 +64,35 @@ enum {
 	VHOST_NET_VQ_MAX = 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];
 	/* Number of TX recently submitted.
 	 * Protected by tx vq lock. */
@@ -78,6 +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;
@@ -153,10 +263,12 @@ static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
 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)) {
@@ -168,7 +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;
 }
 
@@ -198,7 +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 = {
@@ -224,8 +337,8 @@ static void handle_tx(struct vhost_net *net)
 	mutex_lock(&vq->mutex);
 	vhost_disable_notify(&net->dev, vq);
 
-	hdr_size = vq->vhost_hlen;
-	zcopy = vq->ubufs;
+	hdr_size = nvq->vhost_hlen;
+	zcopy = nvq->ubufs;
 
 	for (;;) {
 		/* Release DMAs done buffers first */
@@ -246,9 +359,10 @@ static void handle_tx(struct vhost_net *net)
 			/* 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);
+			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))) {
@@ -263,45 +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;
-				ubuf = vq->ubuf_info + vq->upend_idx;
+				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);
@@ -309,8 +423,8 @@ 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);
 			break;
@@ -417,7 +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 = {
@@ -445,8 +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;
@@ -476,11 +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);
@@ -494,7 +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);
@@ -502,7 +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");
@@ -559,17 +674,34 @@ 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;
 	}
 
@@ -584,7 +716,9 @@ 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_poll *poll = n->poll + (vq - n->vqs);
+	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;
 	vhost_poll_stop(poll);
@@ -593,7 +727,9 @@ static void vhost_net_disable_vq(struct vhost_net *n,
 static int vhost_net_enable_vq(struct vhost_net *n,
 				struct vhost_virtqueue *vq)
 {
-	struct vhost_poll *poll = n->poll + (vq - n->vqs);
+	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;
 
 	sock = rcu_dereference_protected(vq->private_data,
@@ -621,30 +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);
 	}
 }
 
@@ -658,6 +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)
@@ -665,6 +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;
 }
@@ -738,6 +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;
 
@@ -750,7 +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. */
@@ -783,8 +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;
@@ -827,14 +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)
@@ -870,10 +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);
@@ -910,11 +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;
 	}