[PATCH v6 15/46] virtio_net: v1.0 endianness

[PATCH v6 15/46] virtio_net: v1.0 endianness

[Michael S. Tsirkin]

Based on patches by Rusty Russell, Cornelia Huck.
Note: more code changes are needed for 1.0 support
(due to different header size).
So we don't advertize support for 1.0 yet.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/uapi/linux/virtio_net.h | 15 ++++++++-------
 drivers/net/virtio_net.c        | 33 ++++++++++++++++++++-------------
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 172a7f0..b5f1677 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -28,6 +28,7 @@
 #include <linux/types.h>
 #include <linux/virtio_ids.h>
 #include <linux/virtio_config.h>
+#include <linux/virtio_types.h>
 #include <linux/if_ether.h>
 
 /* The feature bitmap for virtio net */
@@ -84,17 +85,17 @@ struct virtio_net_hdr {
 #define VIRTIO_NET_HDR_GSO_TCPV6	4	// GSO frame, IPv6 TCP
 #define VIRTIO_NET_HDR_GSO_ECN		0x80	// TCP has ECN set
 	__u8 gso_type;
-	__u16 hdr_len;		/* Ethernet + IP + tcp/udp hdrs */
-	__u16 gso_size;		/* Bytes to append to hdr_len per frame */
-	__u16 csum_start;	/* Position to start checksumming from */
-	__u16 csum_offset;	/* Offset after that to place checksum */
+	__virtio16 hdr_len;		/* Ethernet + IP + tcp/udp hdrs */
+	__virtio16 gso_size;		/* Bytes to append to hdr_len per frame */
+	__virtio16 csum_start;	/* Position to start checksumming from */
+	__virtio16 csum_offset;	/* Offset after that to place checksum */
 };
 
 /* This is the version of the header to use when the MRG_RXBUF
  * feature has been negotiated. */
 struct virtio_net_hdr_mrg_rxbuf {
 	struct virtio_net_hdr hdr;
-	__u16 num_buffers;	/* Number of merged rx buffers */
+	__virtio16 num_buffers;	/* Number of merged rx buffers */
 };
 
 /*
@@ -149,7 +150,7 @@ typedef __u8 virtio_net_ctrl_ack;
  * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
  */
 struct virtio_net_ctrl_mac {
-	__u32 entries;
+	__virtio32 entries;
 	__u8 macs[][ETH_ALEN];
 } __attribute__((packed));
 
@@ -193,7 +194,7 @@ struct virtio_net_ctrl_mac {
  * specified.
  */
 struct virtio_net_ctrl_mq {
-	__u16 virtqueue_pairs;
+	__virtio16 virtqueue_pairs;
 };
 
 #define VIRTIO_NET_CTRL_MQ   4
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index b0bc8ea..c07e030 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -347,13 +347,14 @@ err:
 }
 
 static struct sk_buff *receive_mergeable(struct net_device *dev,
+					 struct virtnet_info *vi,
 					 struct receive_queue *rq,
 					 unsigned long ctx,
 					 unsigned int len)
 {
 	void *buf = mergeable_ctx_to_buf_address(ctx);
 	struct skb_vnet_hdr *hdr = buf;
-	int num_buf = hdr->mhdr.num_buffers;
+	u16 num_buf = virtio16_to_cpu(rq->vq->vdev, hdr->mhdr.num_buffers);
 	struct page *page = virt_to_head_page(buf);
 	int offset = buf - page_address(page);
 	unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
@@ -369,7 +370,9 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 		ctx = (unsigned long)virtqueue_get_buf(rq->vq, &len);
 		if (unlikely(!ctx)) {
 			pr_debug("%s: rx error: %d buffers out of %d missing\n",
-				 dev->name, num_buf, hdr->mhdr.num_buffers);
+				 dev->name, num_buf,
+				 virtio16_to_cpu(rq->vq->vdev,
+						 hdr->mhdr.num_buffers));
 			dev->stats.rx_length_errors++;
 			goto err_buf;
 		}
@@ -454,7 +457,7 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 	}
 
 	if (vi->mergeable_rx_bufs)
-		skb = receive_mergeable(dev, rq, (unsigned long)buf, len);
+		skb = receive_mergeable(dev, vi, rq, (unsigned long)buf, len);
 	else if (vi->big_packets)
 		skb = receive_big(dev, rq, buf, len);
 	else
@@ -473,8 +476,8 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 		pr_debug("Needs csum!\n");
 		if (!skb_partial_csum_set(skb,
-					  hdr->hdr.csum_start,
-					  hdr->hdr.csum_offset))
+			  virtio16_to_cpu(vi->vdev, hdr->hdr.csum_start),
+			  virtio16_to_cpu(vi->vdev, hdr->hdr.csum_offset)))
 			goto frame_err;
 	} else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
@@ -514,7 +517,8 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 		if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 			skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 
-		skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
+		skb_shinfo(skb)->gso_size = virtio16_to_cpu(vi->vdev,
+							    hdr->hdr.gso_size);
 		if (skb_shinfo(skb)->gso_size == 0) {
 			net_warn_ratelimited("%s: zero gso size.\n", dev->name);
 			goto frame_err;
@@ -876,16 +880,19 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-		hdr->hdr.csum_start = skb_checksum_start_offset(skb);
-		hdr->hdr.csum_offset = skb->csum_offset;
+		hdr->hdr.csum_start = cpu_to_virtio16(vi->vdev,
+						skb_checksum_start_offset(skb));
+		hdr->hdr.csum_offset = cpu_to_virtio16(vi->vdev,
+							 skb->csum_offset);
 	} else {
 		hdr->hdr.flags = 0;
 		hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
 	}
 
 	if (skb_is_gso(skb)) {
-		hdr->hdr.hdr_len = skb_headlen(skb);
-		hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
+		hdr->hdr.hdr_len = cpu_to_virtio16(vi->vdev, skb_headlen(skb));
+		hdr->hdr.gso_size = cpu_to_virtio16(vi->vdev,
+						    skb_shinfo(skb)->gso_size);
 		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
 			hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 		else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
@@ -1112,7 +1119,7 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 	if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
 		return 0;
 
-	s.virtqueue_pairs = queue_pairs;
+	s.virtqueue_pairs = cpu_to_virtio16(vi->vdev, queue_pairs);
 	sg_init_one(&sg, &s, sizeof(s));
 
 	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
@@ -1189,7 +1196,7 @@ static void virtnet_set_rx_mode(struct net_device *dev)
 	sg_init_table(sg, 2);
 
 	/* Store the unicast list and count in the front of the buffer */
-	mac_data->entries = uc_count;
+	mac_data->entries = cpu_to_virtio32(vi->vdev, uc_count);
 	i = 0;
 	netdev_for_each_uc_addr(ha, dev)
 		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
@@ -1200,7 +1207,7 @@ static void virtnet_set_rx_mode(struct net_device *dev)
 	/* multicast list and count fill the end */
 	mac_data = (void *)&mac_data->macs[uc_count][0];
 
-	mac_data->entries = mc_count;
+	mac_data->entries = cpu_to_virtio32(vi->vdev, mc_count);
 	i = 0;
 	netdev_for_each_mc_addr(ha, dev)
 		memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);
-- 
MST

[PATCH v6 23/46] virtio_net: pass vi around

[Michael S. Tsirkin]

Too many places poke at [rs]q->vq->vdev->priv just to get
the vi structure.  Let's just pass the pointer around: seems
cleaner, and might even be faster.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 drivers/net/virtio_net.c | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c07e030..1630c21 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -241,11 +241,11 @@ static unsigned long mergeable_buf_to_ctx(void *buf, unsigned int truesize)
 }
 
 /* Called from bottom half context */
-static struct sk_buff *page_to_skb(struct receive_queue *rq,
+static struct sk_buff *page_to_skb(struct virtnet_info *vi,
+				   struct receive_queue *rq,
 				   struct page *page, unsigned int offset,
 				   unsigned int len, unsigned int truesize)
 {
-	struct virtnet_info *vi = rq->vq->vdev->priv;
 	struct sk_buff *skb;
 	struct skb_vnet_hdr *hdr;
 	unsigned int copy, hdr_len, hdr_padded_len;
@@ -328,12 +328,13 @@ static struct sk_buff *receive_small(void *buf, unsigned int len)
 }
 
 static struct sk_buff *receive_big(struct net_device *dev,
+				   struct virtnet_info *vi,
 				   struct receive_queue *rq,
 				   void *buf,
 				   unsigned int len)
 {
 	struct page *page = buf;
-	struct sk_buff *skb = page_to_skb(rq, page, 0, len, PAGE_SIZE);
+	struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 
 	if (unlikely(!skb))
 		goto err;
@@ -359,7 +360,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 	int offset = buf - page_address(page);
 	unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
 
-	struct sk_buff *head_skb = page_to_skb(rq, page, offset, len, truesize);
+	struct sk_buff *head_skb = page_to_skb(vi, rq, page, offset, len,
+					       truesize);
 	struct sk_buff *curr_skb = head_skb;
 
 	if (unlikely(!curr_skb))
@@ -433,9 +435,9 @@ err_buf:
 	return NULL;
 }
 
-static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
+static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
+			void *buf, unsigned int len)
 {
-	struct virtnet_info *vi = rq->vq->vdev->priv;
 	struct net_device *dev = vi->dev;
 	struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 	struct sk_buff *skb;
@@ -459,7 +461,7 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
 	if (vi->mergeable_rx_bufs)
 		skb = receive_mergeable(dev, vi, rq, (unsigned long)buf, len);
 	else if (vi->big_packets)
-		skb = receive_big(dev, rq, buf, len);
+		skb = receive_big(dev, vi, rq, buf, len);
 	else
 		skb = receive_small(buf, len);
 
@@ -539,9 +541,9 @@ frame_err:
 	dev_kfree_skb(skb);
 }
 
-static int add_recvbuf_small(struct receive_queue *rq, gfp_t gfp)
+static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
+			     gfp_t gfp)
 {
-	struct virtnet_info *vi = rq->vq->vdev->priv;
 	struct sk_buff *skb;
 	struct skb_vnet_hdr *hdr;
 	int err;
@@ -664,9 +666,9 @@ static int add_recvbuf_mergeable(struct receive_queue *rq, gfp_t gfp)
  * before we're receiving packets, or from refill_work which is
  * careful to disable receiving (using napi_disable).
  */
-static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
+static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
+			  gfp_t gfp)
 {
-	struct virtnet_info *vi = rq->vq->vdev->priv;
 	int err;
 	bool oom;
 
@@ -677,7 +679,7 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
 		else if (vi->big_packets)
 			err = add_recvbuf_big(rq, gfp);
 		else
-			err = add_recvbuf_small(rq, gfp);
+			err = add_recvbuf_small(vi, rq, gfp);
 
 		oom = err == -ENOMEM;
 		if (err)
@@ -726,7 +728,7 @@ static void refill_work(struct work_struct *work)
 		struct receive_queue *rq = &vi->rq[i];
 
 		napi_disable(&rq->napi);
-		still_empty = !try_fill_recv(rq, GFP_KERNEL);
+		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
 		virtnet_napi_enable(rq);
 
 		/* In theory, this can happen: if we don't get any buffers in
@@ -745,12 +747,12 @@ static int virtnet_receive(struct receive_queue *rq, int budget)
 
 	while (received < budget &&
 	       (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
-		receive_buf(rq, buf, len);
+		receive_buf(vi, rq, buf, len);
 		received++;
 	}
 
 	if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {
-		if (!try_fill_recv(rq, GFP_ATOMIC))
+		if (!try_fill_recv(vi, rq, GFP_ATOMIC))
 			schedule_delayed_work(&vi->refill, 0);
 	}
 
@@ -826,7 +828,7 @@ static int virtnet_open(struct net_device *dev)
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		if (i < vi->curr_queue_pairs)
 			/* Make sure we have some buffers: if oom use wq. */
-			if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
+			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
 				schedule_delayed_work(&vi->refill, 0);
 		virtnet_napi_enable(&vi->rq[i]);
 	}
@@ -1851,7 +1853,7 @@ static int virtnet_probe(struct virtio_device *vdev)
 
 	/* Last of all, set up some receive buffers. */
 	for (i = 0; i < vi->curr_queue_pairs; i++) {
-		try_fill_recv(&vi->rq[i], GFP_KERNEL);
+		try_fill_recv(vi, &vi->rq[i], GFP_KERNEL);
 
 		/* If we didn't even get one input buffer, we're useless. */
 		if (vi->rq[i].vq->num_free ==
@@ -1971,7 +1973,7 @@ static int virtnet_restore(struct virtio_device *vdev)
 
 	if (netif_running(vi->dev)) {
 		for (i = 0; i < vi->curr_queue_pairs; i++)
-			if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
+			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
 				schedule_delayed_work(&vi->refill, 0);
 
 		for (i = 0; i < vi->max_queue_pairs; i++)
-- 
MST

[PATCH v6 24/46] virtio_net: get rid of virtio_net_hdr/skb_vnet_hdr

[Michael S. Tsirkin]

virtio 1.0 doesn't use virtio_net_hdr anymore, and in fact, it's not
really useful since virtio_net_hdr_mrg_rxbuf includes that as the first
field anyway.

Let's drop it, precalculate header len and store within vi instead.

This way we can also remove struct skb_vnet_hdr.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 drivers/net/virtio_net.c | 90 ++++++++++++++++++++++--------------------------
 1 file changed, 41 insertions(+), 49 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 1630c21..516f2cb 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -123,6 +123,9 @@ struct virtnet_info {
 	/* Host can handle any s/g split between our header and packet data */
 	bool any_header_sg;
 
+	/* Packet virtio header size */
+	u8 hdr_len;
+
 	/* Active statistics */
 	struct virtnet_stats __percpu *stats;
 
@@ -139,21 +142,14 @@ struct virtnet_info {
 	struct notifier_block nb;
 };
 
-struct skb_vnet_hdr {
-	union {
-		struct virtio_net_hdr hdr;
-		struct virtio_net_hdr_mrg_rxbuf mhdr;
-	};
-};
-
 struct padded_vnet_hdr {
-	struct virtio_net_hdr hdr;
+	struct virtio_net_hdr_mrg_rxbuf hdr;
 	/*
-	 * virtio_net_hdr should be in a separated sg buffer because of a
-	 * QEMU bug, and data sg buffer shares same page with this header sg.
-	 * This padding makes next sg 16 byte aligned after virtio_net_hdr.
+	 * hdr is in a separate sg buffer, and data sg buffer shares same page
+	 * with this header sg. This padding makes next sg 16 byte aligned
+	 * after the header.
 	 */
-	char padding[6];
+	char padding[4];
 };
 
 /* Converting between virtqueue no. and kernel tx/rx queue no.
@@ -179,9 +175,9 @@ static int rxq2vq(int rxq)
 	return rxq * 2;
 }
 
-static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
+static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
 {
-	return (struct skb_vnet_hdr *)skb->cb;
+	return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
 }
 
 /*
@@ -247,7 +243,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 				   unsigned int len, unsigned int truesize)
 {
 	struct sk_buff *skb;
-	struct skb_vnet_hdr *hdr;
+	struct virtio_net_hdr_mrg_rxbuf *hdr;
 	unsigned int copy, hdr_len, hdr_padded_len;
 	char *p;
 
@@ -260,13 +256,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 
 	hdr = skb_vnet_hdr(skb);
 
-	if (vi->mergeable_rx_bufs) {
-		hdr_len = sizeof hdr->mhdr;
-		hdr_padded_len = sizeof hdr->mhdr;
-	} else {
-		hdr_len = sizeof hdr->hdr;
+	hdr_len = vi->hdr_len;
+	if (vi->mergeable_rx_bufs)
+		hdr_padded_len = sizeof *hdr;
+	else
 		hdr_padded_len = sizeof(struct padded_vnet_hdr);
-	}
 
 	memcpy(hdr, p, hdr_len);
 
@@ -317,11 +311,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 	return skb;
 }
 
-static struct sk_buff *receive_small(void *buf, unsigned int len)
+static struct sk_buff *receive_small(struct virtnet_info *vi, void *buf, unsigned int len)
 {
 	struct sk_buff * skb = buf;
 
-	len -= sizeof(struct virtio_net_hdr);
+	len -= vi->hdr_len;
 	skb_trim(skb, len);
 
 	return skb;
@@ -354,8 +348,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 					 unsigned int len)
 {
 	void *buf = mergeable_ctx_to_buf_address(ctx);
-	struct skb_vnet_hdr *hdr = buf;
-	u16 num_buf = virtio16_to_cpu(rq->vq->vdev, hdr->mhdr.num_buffers);
+	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
+	u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
 	struct page *page = virt_to_head_page(buf);
 	int offset = buf - page_address(page);
 	unsigned int truesize = max(len, mergeable_ctx_to_buf_truesize(ctx));
@@ -373,8 +367,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 		if (unlikely(!ctx)) {
 			pr_debug("%s: rx error: %d buffers out of %d missing\n",
 				 dev->name, num_buf,
-				 virtio16_to_cpu(rq->vq->vdev,
-						 hdr->mhdr.num_buffers));
+				 virtio16_to_cpu(vi->vdev,
+						 hdr->num_buffers));
 			dev->stats.rx_length_errors++;
 			goto err_buf;
 		}
@@ -441,7 +435,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 	struct net_device *dev = vi->dev;
 	struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 	struct sk_buff *skb;
-	struct skb_vnet_hdr *hdr;
+	struct virtio_net_hdr_mrg_rxbuf *hdr;
 
 	if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
 		pr_debug("%s: short packet %i\n", dev->name, len);
@@ -463,7 +457,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 	else if (vi->big_packets)
 		skb = receive_big(dev, vi, rq, buf, len);
 	else
-		skb = receive_small(buf, len);
+		skb = receive_small(vi, buf, len);
 
 	if (unlikely(!skb))
 		return;
@@ -545,7 +539,7 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 			     gfp_t gfp)
 {
 	struct sk_buff *skb;
-	struct skb_vnet_hdr *hdr;
+	struct virtio_net_hdr_mrg_rxbuf *hdr;
 	int err;
 
 	skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
@@ -556,7 +550,7 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 
 	hdr = skb_vnet_hdr(skb);
 	sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
-	sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
+	sg_set_buf(rq->sg, hdr, vi->hdr_len);
 	skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
 
 	err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
@@ -566,7 +560,8 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 	return err;
 }
 
-static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
+static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
+			   gfp_t gfp)
 {
 	struct page *first, *list = NULL;
 	char *p;
@@ -597,8 +592,8 @@ static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
 	p = page_address(first);
 
 	/* rq->sg[0], rq->sg[1] share the same page */
-	/* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
-	sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
+	/* a separated rq->sg[0] for header - required in case !any_header_sg */
+	sg_set_buf(&rq->sg[0], p, vi->hdr_len);
 
 	/* rq->sg[1] for data packet, from offset */
 	offset = sizeof(struct padded_vnet_hdr);
@@ -677,7 +672,7 @@ static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq,
 		if (vi->mergeable_rx_bufs)
 			err = add_recvbuf_mergeable(rq, gfp);
 		else if (vi->big_packets)
-			err = add_recvbuf_big(rq, gfp);
+			err = add_recvbuf_big(vi, rq, gfp);
 		else
 			err = add_recvbuf_small(vi, rq, gfp);
 
@@ -857,18 +852,14 @@ static void free_old_xmit_skbs(struct send_queue *sq)
 
 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 {
-	struct skb_vnet_hdr *hdr;
+	struct virtio_net_hdr_mrg_rxbuf *hdr;
 	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 	struct virtnet_info *vi = sq->vq->vdev->priv;
 	unsigned num_sg;
-	unsigned hdr_len;
+	unsigned hdr_len = vi->hdr_len;
 	bool can_push;
 
 	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
-	if (vi->mergeable_rx_bufs)
-		hdr_len = sizeof hdr->mhdr;
-	else
-		hdr_len = sizeof hdr->hdr;
 
 	can_push = vi->any_header_sg &&
 		!((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
@@ -876,7 +867,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 	/* Even if we can, don't push here yet as this would skew
 	 * csum_start offset below. */
 	if (can_push)
-		hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
+		hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
 	else
 		hdr = skb_vnet_hdr(skb);
 
@@ -909,7 +900,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 	}
 
 	if (vi->mergeable_rx_bufs)
-		hdr->mhdr.num_buffers = 0;
+		hdr->num_buffers = 0;
 
 	sg_init_table(sq->sg, MAX_SKB_FRAGS + 2);
 	if (can_push) {
@@ -1814,18 +1805,19 @@ static int virtnet_probe(struct virtio_device *vdev)
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
 		vi->mergeable_rx_bufs = true;
 
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
+		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+	else
+		vi->hdr_len = sizeof(struct virtio_net_hdr);
+
 	if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
 		vi->any_header_sg = true;
 
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
 		vi->has_cvq = true;
 
-	if (vi->any_header_sg) {
-		if (vi->mergeable_rx_bufs)
-			dev->needed_headroom = sizeof(struct virtio_net_hdr_mrg_rxbuf);
-		else
-			dev->needed_headroom = sizeof(struct virtio_net_hdr);
-	}
+	if (vi->any_header_sg)
+		dev->needed_headroom = vi->hdr_len;
 
 	/* Use single tx/rx queue pair as default */
 	vi->curr_queue_pairs = 1;
-- 
MST

Re: [PATCH v6 24/46] virtio_net: get rid of virtio_net_hdr/skb_vnet_hdr

[Jason Wang]

On Fri, Nov 28, 2014 at 4:09 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> virtio 1.0 doesn't use virtio_net_hdr anymore, and in fact, it's not
> really useful since virtio_net_hdr_mrg_rxbuf includes that as the 
> first
> field anyway.
> 
> Let's drop it, precalculate header len and store within vi instead.
> 
> This way we can also remove struct skb_vnet_hdr.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> ---
>  drivers/net/virtio_net.c | 90 
> ++++++++++++++++++++++--------------------------
>  1 file changed, 41 insertions(+), 49 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 1630c21..516f2cb 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -123,6 +123,9 @@ struct virtnet_info {
>  	/* Host can handle any s/g split between our header and packet data 
> */
>  	bool any_header_sg;
>  
> +	/* Packet virtio header size */
> +	u8 hdr_len;
> +
>  	/* Active statistics */
>  	struct virtnet_stats __percpu *stats;
>  
> @@ -139,21 +142,14 @@ struct virtnet_info {
>  	struct notifier_block nb;
>  };
>  
> -struct skb_vnet_hdr {
> -	union {
> -		struct virtio_net_hdr hdr;
> -		struct virtio_net_hdr_mrg_rxbuf mhdr;
> -	};
> -};
> -
>  struct padded_vnet_hdr {
> -	struct virtio_net_hdr hdr;
> +	struct virtio_net_hdr_mrg_rxbuf hdr;
>  	/*
> -	 * virtio_net_hdr should be in a separated sg buffer because of a
> -	 * QEMU bug, and data sg buffer shares same page with this header 
> sg.
> -	 * This padding makes next sg 16 byte aligned after virtio_net_hdr.
> +	 * hdr is in a separate sg buffer, and data sg buffer shares same 
> page
> +	 * with this header sg. This padding makes next sg 16 byte aligned
> +	 * after the header.
>  	 */
> -	char padding[6];
> +	char padding[4];
>  };
>  
>  /* Converting between virtqueue no. and kernel tx/rx queue no.
> @@ -179,9 +175,9 @@ static int rxq2vq(int rxq)
>  	return rxq * 2;
>  }
>  
> -static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
> +static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct 
> sk_buff *skb)
>  {
> -	return (struct skb_vnet_hdr *)skb->cb;
> +	return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
>  }
>  
>  /*
> @@ -247,7 +243,7 @@ static struct sk_buff *page_to_skb(struct 
> virtnet_info *vi,
>  				   unsigned int len, unsigned int truesize)
>  {
>  	struct sk_buff *skb;
> -	struct skb_vnet_hdr *hdr;
> +	struct virtio_net_hdr_mrg_rxbuf *hdr;
>  	unsigned int copy, hdr_len, hdr_padded_len;
>  	char *p;
>  
> @@ -260,13 +256,11 @@ static struct sk_buff *page_to_skb(struct 
> virtnet_info *vi,
>  
>  	hdr = skb_vnet_hdr(skb);
>  
> -	if (vi->mergeable_rx_bufs) {
> -		hdr_len = sizeof hdr->mhdr;
> -		hdr_padded_len = sizeof hdr->mhdr;
> -	} else {
> -		hdr_len = sizeof hdr->hdr;
> +	hdr_len = vi->hdr_len;
> +	if (vi->mergeable_rx_bufs)
> +		hdr_padded_len = sizeof *hdr;
> +	else
>  		hdr_padded_len = sizeof(struct padded_vnet_hdr);
> -	}
>  
>  	memcpy(hdr, p, hdr_len);
>  
> @@ -317,11 +311,11 @@ static struct sk_buff *page_to_skb(struct 
> virtnet_info *vi,
>  	return skb;
>  }
>  
> -static struct sk_buff *receive_small(void *buf, unsigned int len)
> +static struct sk_buff *receive_small(struct virtnet_info *vi, void 
> *buf, unsigned int len)
>  {
>  	struct sk_buff * skb = buf;
>  
> -	len -= sizeof(struct virtio_net_hdr);
> +	len -= vi->hdr_len;
>  	skb_trim(skb, len);
>  
>  	return skb;
> @@ -354,8 +348,8 @@ static struct sk_buff *receive_mergeable(struct 
> net_device *dev,
>  					 unsigned int len)
>  {
>  	void *buf = mergeable_ctx_to_buf_address(ctx);
> -	struct skb_vnet_hdr *hdr = buf;
> -	u16 num_buf = virtio16_to_cpu(rq->vq->vdev, hdr->mhdr.num_buffers);
> +	struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
> +	u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
>  	struct page *page = virt_to_head_page(buf);
>  	int offset = buf - page_address(page);
>  	unsigned int truesize = max(len, 
> mergeable_ctx_to_buf_truesize(ctx));
> @@ -373,8 +367,8 @@ static struct sk_buff *receive_mergeable(struct 
> net_device *dev,
>  		if (unlikely(!ctx)) {
>  			pr_debug("%s: rx error: %d buffers out of %d missing\n",
>  				 dev->name, num_buf,
> -				 virtio16_to_cpu(rq->vq->vdev,
> -						 hdr->mhdr.num_buffers));
> +				 virtio16_to_cpu(vi->vdev,
> +						 hdr->num_buffers));
>  			dev->stats.rx_length_errors++;
>  			goto err_buf;
>  		}
> @@ -441,7 +435,7 @@ static void receive_buf(struct virtnet_info *vi, 
> struct receive_queue *rq,
>  	struct net_device *dev = vi->dev;
>  	struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
>  	struct sk_buff *skb;
> -	struct skb_vnet_hdr *hdr;
> +	struct virtio_net_hdr_mrg_rxbuf *hdr;
>  
>  	if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
>  		pr_debug("%s: short packet %i\n", dev->name, len);
> @@ -463,7 +457,7 @@ static void receive_buf(struct virtnet_info *vi, 
> struct receive_queue *rq,
>  	else if (vi->big_packets)
>  		skb = receive_big(dev, vi, rq, buf, len);
>  	else
> -		skb = receive_small(buf, len);
> +		skb = receive_small(vi, buf, len);
>  
>  	if (unlikely(!skb))
>  		return;
> @@ -545,7 +539,7 @@ static int add_recvbuf_small(struct virtnet_info 
> *vi, struct receive_queue *rq,
>  			     gfp_t gfp)
>  {
>  	struct sk_buff *skb;
> -	struct skb_vnet_hdr *hdr;
> +	struct virtio_net_hdr_mrg_rxbuf *hdr;
>  	int err;
>  
>  	skb = __netdev_alloc_skb_ip_align(vi->dev, GOOD_PACKET_LEN, gfp);
> @@ -556,7 +550,7 @@ static int add_recvbuf_small(struct virtnet_info 
> *vi, struct receive_queue *rq,
>  
>  	hdr = skb_vnet_hdr(skb);
>  	sg_init_table(rq->sg, MAX_SKB_FRAGS + 2);
> -	sg_set_buf(rq->sg, &hdr->hdr, sizeof hdr->hdr);
> +	sg_set_buf(rq->sg, hdr, vi->hdr_len);
>  	skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
>  
>  	err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
> @@ -566,7 +560,8 @@ static int add_recvbuf_small(struct virtnet_info 
> *vi, struct receive_queue *rq,
>  	return err;
>  }
>  
> -static int add_recvbuf_big(struct receive_queue *rq, gfp_t gfp)
> +static int add_recvbuf_big(struct virtnet_info *vi, struct 
> receive_queue *rq,
> +			   gfp_t gfp)
>  {
>  	struct page *first, *list = NULL;
>  	char *p;
> @@ -597,8 +592,8 @@ static int add_recvbuf_big(struct receive_queue 
> *rq, gfp_t gfp)
>  	p = page_address(first);
>  
>  	/* rq->sg[0], rq->sg[1] share the same page */
> -	/* a separated rq->sg[0] for virtio_net_hdr only due to QEMU bug */
> -	sg_set_buf(&rq->sg[0], p, sizeof(struct virtio_net_hdr));
> +	/* a separated rq->sg[0] for header - required in case 
> !any_header_sg */
> +	sg_set_buf(&rq->sg[0], p, vi->hdr_len);
>  
>  	/* rq->sg[1] for data packet, from offset */
>  	offset = sizeof(struct padded_vnet_hdr);
> @@ -677,7 +672,7 @@ static bool try_fill_recv(struct virtnet_info 
> *vi, struct receive_queue *rq,
>  		if (vi->mergeable_rx_bufs)
>  			err = add_recvbuf_mergeable(rq, gfp);
>  		else if (vi->big_packets)
> -			err = add_recvbuf_big(rq, gfp);
> +			err = add_recvbuf_big(vi, rq, gfp);
>  		else
>  			err = add_recvbuf_small(vi, rq, gfp);
>  
> @@ -857,18 +852,14 @@ static void free_old_xmit_skbs(struct 
> send_queue *sq)
>  
>  static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
>  {
> -	struct skb_vnet_hdr *hdr;
> +	struct virtio_net_hdr_mrg_rxbuf *hdr;
>  	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
>  	struct virtnet_info *vi = sq->vq->vdev->priv;
>  	unsigned num_sg;
> -	unsigned hdr_len;
> +	unsigned hdr_len = vi->hdr_len;
>  	bool can_push;
>  
>  	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
> -	if (vi->mergeable_rx_bufs)
> -		hdr_len = sizeof hdr->mhdr;
> -	else
> -		hdr_len = sizeof hdr->hdr;
>  
>  	can_push = vi->any_header_sg &&
>  		!((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
> @@ -876,7 +867,7 @@ static int xmit_skb(struct send_queue *sq, struct 
> sk_buff *skb)
>  	/* Even if we can, don't push here yet as this would skew
>  	 * csum_start offset below. */
>  	if (can_push)
> -		hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
> +		hdr = (struct virtio_net_hdr_mrg_rxbuf *)(skb->data - hdr_len);
>  	else
>  		hdr = skb_vnet_hdr(skb);
>  
> @@ -909,7 +900,7 @@ static int xmit_skb(struct send_queue *sq, struct 
> sk_buff *skb)
>  	}
>  
>  	if (vi->mergeable_rx_bufs)
> -		hdr->mhdr.num_buffers = 0;
> +		hdr->num_buffers = 0;
>  
>  	sg_init_table(sq->sg, MAX_SKB_FRAGS + 2);
>  	if (can_push) {
> @@ -1814,18 +1805,19 @@ static int virtnet_probe(struct virtio_device 
> *vdev)
>  	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
>  		vi->mergeable_rx_bufs = true;
>  
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
> +		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
> +	else
> +		vi->hdr_len = sizeof(struct virtio_net_hdr);
> +
>  	if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
>  		vi->any_header_sg = true;
>  
>  	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
>  		vi->has_cvq = true;
>  
> -	if (vi->any_header_sg) {
> -		if (vi->mergeable_rx_bufs)
> -			dev->needed_headroom = sizeof(struct virtio_net_hdr_mrg_rxbuf);
> -		else
> -			dev->needed_headroom = sizeof(struct virtio_net_hdr);
> -	}
> +	if (vi->any_header_sg)
> +		dev->needed_headroom = vi->hdr_len;
>  
>  	/* Use single tx/rx queue pair as default */
>  	vi->curr_queue_pairs = 1;
> -- 
> MST

Reviewed-by: Jason Wang <jasowang@redhat.com>

[PATCH v6 25/46] virtio_net: stricter short buffer length checks

[Michael S. Tsirkin]

Our buffer length check is not strict enough for mergeable
buffers: buffer can still be shorter that header + address
by 2 bytes.

Fix that up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 drivers/net/virtio_net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 516f2cb..098f443 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -437,7 +437,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 	struct sk_buff *skb;
 	struct virtio_net_hdr_mrg_rxbuf *hdr;
 
-	if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
+	if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
 		pr_debug("%s: short packet %i\n", dev->name, len);
 		dev->stats.rx_length_errors++;
 		if (vi->mergeable_rx_bufs) {
-- 
MST

Re: [PATCH v6 25/46] virtio_net: stricter short buffer length checks

[Jason Wang]

On Fri, Nov 28, 2014 at 4:09 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> Our buffer length check is not strict enough for mergeable
> buffers: buffer can still be shorter that header + address
> by 2 bytes.
> 
> Fix that up.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> ---
>  drivers/net/virtio_net.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 516f2cb..098f443 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -437,7 +437,7 @@ static void receive_buf(struct virtnet_info *vi, 
> struct receive_queue *rq,
>  	struct sk_buff *skb;
>  	struct virtio_net_hdr_mrg_rxbuf *hdr;
>  
> -	if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
> +	if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
>  		pr_debug("%s: short packet %i\n", dev->name, len);
>  		dev->stats.rx_length_errors++;
>  		if (vi->mergeable_rx_bufs) {
> -- 
> MST

Reviewed-by: Jason Wang <jasowang@redhat.com>

[PATCH v6 26/46] virtio_net: bigger header when VERSION_1 is set

[Michael S. Tsirkin]

With VERSION_1 virtio_net uses same header size
whether mergeable buffers are enabled or not.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 drivers/net/virtio_net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 098f443..a0e64cf 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1805,7 +1805,8 @@ static int virtnet_probe(struct virtio_device *vdev)
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
 		vi->mergeable_rx_bufs = true;
 
-	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
+	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
 		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 	else
 		vi->hdr_len = sizeof(struct virtio_net_hdr);
-- 
MST

Re: [PATCH v6 26/46] virtio_net: bigger header when VERSION_1 is set

[Jason Wang]

On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> With VERSION_1 virtio_net uses same header size
> whether mergeable buffers are enabled or not.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> ---
>  drivers/net/virtio_net.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 098f443..a0e64cf 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1805,7 +1805,8 @@ static int virtnet_probe(struct virtio_device 
> *vdev)
>  	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
>  		vi->mergeable_rx_bufs = true;
>  
> -	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
> +	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
>  		vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
>  	else
>  		vi->hdr_len = sizeof(struct virtio_net_hdr);
> -- 
> MST

Reviewed-by: Jason Wang <jasowang@redhat.com>

[PATCH v6 27/46] virtio_net: enable v1.0 support

[Michael S. Tsirkin]

Now that we have completed 1.0 support, enable it in our driver.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/virtio_net.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index a0e64cf..c6a72d3 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2003,6 +2003,7 @@ static unsigned int features[] = {
 	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
 	VIRTIO_NET_F_CTRL_MAC_ADDR,
 	VIRTIO_F_ANY_LAYOUT,
+	VIRTIO_F_VERSION_1,
 };
 
 static struct virtio_driver virtio_net_driver = {
-- 
MST

[PATCH v6 28/46] vhost: make features 64 bit

[Michael S. Tsirkin]

We need to use bit 32 for virtio 1.0

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/vhost.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 3eda654..c624b09 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -106,7 +106,7 @@ struct vhost_virtqueue {
 	/* Protected by virtqueue mutex. */
 	struct vhost_memory *memory;
 	void *private_data;
-	unsigned acked_features;
+	u64 acked_features;
 	/* Log write descriptors */
 	void __user *log_base;
 	struct vhost_log *log;
@@ -174,6 +174,6 @@ enum {
 
 static inline int vhost_has_feature(struct vhost_virtqueue *vq, int bit)
 {
-	return vq->acked_features & (1 << bit);
+	return vq->acked_features & (1ULL << bit);
 }
 #endif
-- 
MST

Re: [PATCH v6 28/46] vhost: make features 64 bit

[Jason Wang]

On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> We need to use bit 32 for virtio 1.0
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/vhost/vhost.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index 3eda654..c624b09 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -106,7 +106,7 @@ struct vhost_virtqueue {
>  	/* Protected by virtqueue mutex. */
>  	struct vhost_memory *memory;
>  	void *private_data;
> -	unsigned acked_features;
> +	u64 acked_features;
>  	/* Log write descriptors */
>  	void __user *log_base;
>  	struct vhost_log *log;
> @@ -174,6 +174,6 @@ enum {
>  
>  static inline int vhost_has_feature(struct vhost_virtqueue *vq, int 
> bit)
>  {
> -	return vq->acked_features & (1 << bit);
> +	return vq->acked_features & (1ULL << bit);
>  }
>  #endif
> -- 
> MST

Reviewed-by: Jason Wang <jasowang@redhat.com>

[PATCH v6 29/46] vhost: add memory access wrappers

[Michael S. Tsirkin]

Add guest memory access wrappers to handle virtio endianness
conversions.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/vhost.h | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index c624b09..1f321fd 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -176,4 +176,35 @@ static inline int vhost_has_feature(struct vhost_virtqueue *vq, int bit)
 {
 	return vq->acked_features & (1ULL << bit);
 }
+
+/* Memory accessors */
+static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
+{
+	return __virtio16_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
+{
+	return __cpu_to_virtio16(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
+{
+	return __virtio32_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
+{
+	return __cpu_to_virtio32(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
+{
+	return __virtio64_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
+{
+	return __cpu_to_virtio64(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
 #endif
-- 
MST

Re: [PATCH v6 29/46] vhost: add memory access wrappers

[Jason Wang]

On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> Add guest memory access wrappers to handle virtio endianness
> conversions.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/vhost/vhost.h | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index c624b09..1f321fd 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -176,4 +176,35 @@ static inline int vhost_has_feature(struct 
> vhost_virtqueue *vq, int bit)
>  {
>  	return vq->acked_features & (1ULL << bit);
>  }
> +
> +/* Memory accessors */
> +static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, 
> __virtio16 val)
> +{
> +	return __virtio16_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), 
> val);
> +}
> +
> +static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, 
> u16 val)
> +{
> +	return __cpu_to_virtio16(vhost_has_feature(vq, VIRTIO_F_VERSION_1), 
> val);
> +}
> +
> +static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, 
> __virtio32 val)
> +{
> +	return __virtio32_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), 
> val);
> +}
> +
> +static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, 
> u32 val)
> +{
> +	return __cpu_to_virtio32(vhost_has_feature(vq, VIRTIO_F_VERSION_1), 
> val);
> +}
> +
> +static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, 
> __virtio64 val)
> +{
> +	return __virtio64_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), 
> val);
> +}
> +
> +static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, 
> u64 val)
> +{
> +	return __cpu_to_virtio64(vhost_has_feature(vq, VIRTIO_F_VERSION_1), 
> val);
> +}
>  #endif
> -- 
> MST

Reviewed-by: Jason Wang <jasowang@redhat.com>

[PATCH v6 30/46] vhost/net: force len for TX to host endian

[Michael S. Tsirkin]

vhost/net keeps a copy of some used ring but (ab)uses length
field for internal house-keeping. This works because
for tx used length is always 0.
Suppress sparse errors: we use native endian-ness internally but never
expose it to guest.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/net.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 8dae2f7..dce5c58 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -48,15 +48,15 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
  * status internally; used for zerocopy tx only.
  */
 /* Lower device DMA failed */
-#define VHOST_DMA_FAILED_LEN	3
+#define VHOST_DMA_FAILED_LEN	((__force __virtio32)3)
 /* Lower device DMA done */
-#define VHOST_DMA_DONE_LEN	2
+#define VHOST_DMA_DONE_LEN	((__force __virtio32)2)
 /* Lower device DMA in progress */
-#define VHOST_DMA_IN_PROGRESS	1
+#define VHOST_DMA_IN_PROGRESS	((__force __virtio32)1)
 /* Buffer unused */
-#define VHOST_DMA_CLEAR_LEN	0
+#define VHOST_DMA_CLEAR_LEN	((__force __virtio32)0)
 
-#define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
+#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
 
 enum {
 	VHOST_NET_FEATURES = VHOST_FEATURES |
-- 
MST

Re: [PATCH v6 30/46] vhost/net: force len for TX to host endian

[Jason Wang]

On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> vhost/net keeps a copy of some used ring but (ab)uses length
> field for internal house-keeping. This works because
> for tx used length is always 0.
> Suppress sparse errors: we use native endian-ness internally but never
> expose it to guest.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/vhost/net.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 8dae2f7..dce5c58 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -48,15 +48,15 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable 
> Zero Copy TX;"
>   * status internally; used for zerocopy tx only.
>   */
>  /* Lower device DMA failed */
> -#define VHOST_DMA_FAILED_LEN	3
> +#define VHOST_DMA_FAILED_LEN	((__force __virtio32)3)
>  /* Lower device DMA done */
> -#define VHOST_DMA_DONE_LEN	2
> +#define VHOST_DMA_DONE_LEN	((__force __virtio32)2)
>  /* Lower device DMA in progress */
> -#define VHOST_DMA_IN_PROGRESS	1
> +#define VHOST_DMA_IN_PROGRESS	((__force __virtio32)1)
>  /* Buffer unused */
> -#define VHOST_DMA_CLEAR_LEN	0
> +#define VHOST_DMA_CLEAR_LEN	((__force __virtio32)0)
>  
> -#define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
> +#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force 
> u32)VHOST_DMA_DONE_LEN)
>  
>  enum {
>  	VHOST_NET_FEATURES = VHOST_FEATURES |
> -- 
> MST

Reviewed-by: Jason Wang <jasowang@redhat.com>

[PATCH v6 31/46] vhost: virtio 1.0 endian-ness support

[Michael S. Tsirkin]

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/vhost.c | 93 +++++++++++++++++++++++++++++++--------------------
 1 file changed, 56 insertions(+), 37 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index c90f437..4d379ed 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -33,8 +33,8 @@ enum {
 	VHOST_MEMORY_F_LOG = 0x1,
 };
 
-#define vhost_used_event(vq) ((u16 __user *)&vq->avail->ring[vq->num])
-#define vhost_avail_event(vq) ((u16 __user *)&vq->used->ring[vq->num])
+#define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num])
+#define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num])
 
 static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
 			    poll_table *pt)
@@ -1001,7 +1001,7 @@ EXPORT_SYMBOL_GPL(vhost_log_write);
 static int vhost_update_used_flags(struct vhost_virtqueue *vq)
 {
 	void __user *used;
-	if (__put_user(vq->used_flags, &vq->used->flags) < 0)
+	if (__put_user(cpu_to_vhost16(vq, vq->used_flags), &vq->used->flags) < 0)
 		return -EFAULT;
 	if (unlikely(vq->log_used)) {
 		/* Make sure the flag is seen before log. */
@@ -1019,7 +1019,7 @@ static int vhost_update_used_flags(struct vhost_virtqueue *vq)
 
 static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event)
 {
-	if (__put_user(vq->avail_idx, vhost_avail_event(vq)))
+	if (__put_user(cpu_to_vhost16(vq, vq->avail_idx), vhost_avail_event(vq)))
 		return -EFAULT;
 	if (unlikely(vq->log_used)) {
 		void __user *used;
@@ -1038,6 +1038,7 @@ static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event)
 
 int vhost_init_used(struct vhost_virtqueue *vq)
 {
+	__virtio16 last_used_idx;
 	int r;
 	if (!vq->private_data)
 		return 0;
@@ -1046,7 +1047,13 @@ int vhost_init_used(struct vhost_virtqueue *vq)
 	if (r)
 		return r;
 	vq->signalled_used_valid = false;
-	return get_user(vq->last_used_idx, &vq->used->idx);
+	if (!access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx))
+		return -EFAULT;
+	r = __get_user(last_used_idx, &vq->used->idx);
+	if (r)
+		return r;
+	vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(vhost_init_used);
 
@@ -1087,16 +1094,16 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
 /* Each buffer in the virtqueues is actually a chain of descriptors.  This
  * function returns the next descriptor in the chain,
  * or -1U if we're at the end. */
-static unsigned next_desc(struct vring_desc *desc)
+static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc)
 {
 	unsigned int next;
 
 	/* If this descriptor says it doesn't chain, we're done. */
-	if (!(desc->flags & VRING_DESC_F_NEXT))
+	if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT)))
 		return -1U;
 
 	/* Check they're not leading us off end of descriptors. */
-	next = desc->next;
+	next = vhost16_to_cpu(vq, desc->next);
 	/* Make sure compiler knows to grab that: we don't want it changing! */
 	/* We will use the result as an index in an array, so most
 	 * architectures only need a compiler barrier here. */
@@ -1113,18 +1120,19 @@ static int get_indirect(struct vhost_virtqueue *vq,
 {
 	struct vring_desc desc;
 	unsigned int i = 0, count, found = 0;
+	u32 len = vhost32_to_cpu(vq, indirect->len);
 	int ret;
 
 	/* Sanity check */
-	if (unlikely(indirect->len % sizeof desc)) {
+	if (unlikely(len % sizeof desc)) {
 		vq_err(vq, "Invalid length in indirect descriptor: "
 		       "len 0x%llx not multiple of 0x%zx\n",
-		       (unsigned long long)indirect->len,
+		       (unsigned long long)vhost32_to_cpu(vq, indirect->len),
 		       sizeof desc);
 		return -EINVAL;
 	}
 
-	ret = translate_desc(vq, indirect->addr, indirect->len, vq->indirect,
+	ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect,
 			     UIO_MAXIOV);
 	if (unlikely(ret < 0)) {
 		vq_err(vq, "Translation failure %d in indirect.\n", ret);
@@ -1135,7 +1143,7 @@ static int get_indirect(struct vhost_virtqueue *vq,
 	 * architectures only need a compiler barrier here. */
 	read_barrier_depends();
 
-	count = indirect->len / sizeof desc;
+	count = len / sizeof desc;
 	/* Buffers are chained via a 16 bit next field, so
 	 * we can have at most 2^16 of these. */
 	if (unlikely(count > USHRT_MAX + 1)) {
@@ -1155,16 +1163,17 @@ static int get_indirect(struct vhost_virtqueue *vq,
 		if (unlikely(memcpy_fromiovec((unsigned char *)&desc,
 					      vq->indirect, sizeof desc))) {
 			vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n",
-			       i, (size_t)indirect->addr + i * sizeof desc);
+			       i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);
 			return -EINVAL;
 		}
-		if (unlikely(desc.flags & VRING_DESC_F_INDIRECT)) {
+		if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) {
 			vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n",
-			       i, (size_t)indirect->addr + i * sizeof desc);
+			       i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);
 			return -EINVAL;
 		}
 
-		ret = translate_desc(vq, desc.addr, desc.len, iov + iov_count,
+		ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
+				     vhost32_to_cpu(vq, desc.len), iov + iov_count,
 				     iov_size - iov_count);
 		if (unlikely(ret < 0)) {
 			vq_err(vq, "Translation failure %d indirect idx %d\n",
@@ -1172,11 +1181,11 @@ static int get_indirect(struct vhost_virtqueue *vq,
 			return ret;
 		}
 		/* If this is an input descriptor, increment that count. */
-		if (desc.flags & VRING_DESC_F_WRITE) {
+		if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) {
 			*in_num += ret;
 			if (unlikely(log)) {
-				log[*log_num].addr = desc.addr;
-				log[*log_num].len = desc.len;
+				log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);
+				log[*log_num].len = vhost32_to_cpu(vq, desc.len);
 				++*log_num;
 			}
 		} else {
@@ -1189,7 +1198,7 @@ static int get_indirect(struct vhost_virtqueue *vq,
 			}
 			*out_num += ret;
 		}
-	} while ((i = next_desc(&desc)) != -1);
+	} while ((i = next_desc(vq, &desc)) != -1);
 	return 0;
 }
 
@@ -1209,15 +1218,18 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 	struct vring_desc desc;
 	unsigned int i, head, found = 0;
 	u16 last_avail_idx;
+	__virtio16 avail_idx;
+	__virtio16 ring_head;
 	int ret;
 
 	/* Check it isn't doing very strange things with descriptor numbers. */
 	last_avail_idx = vq->last_avail_idx;
-	if (unlikely(__get_user(vq->avail_idx, &vq->avail->idx))) {
+	if (unlikely(__get_user(avail_idx, &vq->avail->idx))) {
 		vq_err(vq, "Failed to access avail idx at %p\n",
 		       &vq->avail->idx);
 		return -EFAULT;
 	}
+	vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
 
 	if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {
 		vq_err(vq, "Guest moved used index from %u to %u",
@@ -1234,7 +1246,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 
 	/* Grab the next descriptor number they're advertising, and increment
 	 * the index we've seen. */
-	if (unlikely(__get_user(head,
+	if (unlikely(__get_user(ring_head,
 				&vq->avail->ring[last_avail_idx % vq->num]))) {
 		vq_err(vq, "Failed to read head: idx %d address %p\n",
 		       last_avail_idx,
@@ -1242,6 +1254,8 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 		return -EFAULT;
 	}
 
+	head = vhost16_to_cpu(vq, ring_head);
+
 	/* If their number is silly, that's an error. */
 	if (unlikely(head >= vq->num)) {
 		vq_err(vq, "Guest says index %u > %u is available",
@@ -1274,7 +1288,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 			       i, vq->desc + i);
 			return -EFAULT;
 		}
-		if (desc.flags & VRING_DESC_F_INDIRECT) {
+		if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) {
 			ret = get_indirect(vq, iov, iov_size,
 					   out_num, in_num,
 					   log, log_num, &desc);
@@ -1286,20 +1300,21 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 			continue;
 		}
 
-		ret = translate_desc(vq, desc.addr, desc.len, iov + iov_count,
+		ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
+				     vhost32_to_cpu(vq, desc.len), iov + iov_count,
 				     iov_size - iov_count);
 		if (unlikely(ret < 0)) {
 			vq_err(vq, "Translation failure %d descriptor idx %d\n",
 			       ret, i);
 			return ret;
 		}
-		if (desc.flags & VRING_DESC_F_WRITE) {
+		if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) {
 			/* If this is an input descriptor,
 			 * increment that count. */
 			*in_num += ret;
 			if (unlikely(log)) {
-				log[*log_num].addr = desc.addr;
-				log[*log_num].len = desc.len;
+				log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);
+				log[*log_num].len = vhost32_to_cpu(vq, desc.len);
 				++*log_num;
 			}
 		} else {
@@ -1312,7 +1327,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 			}
 			*out_num += ret;
 		}
-	} while ((i = next_desc(&desc)) != -1);
+	} while ((i = next_desc(vq, &desc)) != -1);
 
 	/* On success, increment avail index. */
 	vq->last_avail_idx++;
@@ -1335,7 +1350,10 @@ EXPORT_SYMBOL_GPL(vhost_discard_vq_desc);
  * want to notify the guest, using eventfd. */
 int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)
 {
-	struct vring_used_elem heads = { head, len };
+	struct vring_used_elem heads = {
+		cpu_to_vhost32(vq, head),
+		cpu_to_vhost32(vq, len)
+	};
 
 	return vhost_add_used_n(vq, &heads, 1);
 }
@@ -1404,7 +1422,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads,
 
 	/* Make sure buffer is written before we update index. */
 	smp_wmb();
-	if (put_user(vq->last_used_idx, &vq->used->idx)) {
+	if (__put_user(cpu_to_vhost16(vq, vq->last_used_idx), &vq->used->idx)) {
 		vq_err(vq, "Failed to increment used idx");
 		return -EFAULT;
 	}
@@ -1422,7 +1440,8 @@ EXPORT_SYMBOL_GPL(vhost_add_used_n);
 
 static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 {
-	__u16 old, new, event;
+	__u16 old, new;
+	__virtio16 event;
 	bool v;
 	/* Flush out used index updates. This is paired
 	 * with the barrier that the Guest executes when enabling
@@ -1434,12 +1453,12 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 		return true;
 
 	if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
-		__u16 flags;
+		__virtio16 flags;
 		if (__get_user(flags, &vq->avail->flags)) {
 			vq_err(vq, "Failed to get flags");
 			return true;
 		}
-		return !(flags & VRING_AVAIL_F_NO_INTERRUPT);
+		return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT));
 	}
 	old = vq->signalled_used;
 	v = vq->signalled_used_valid;
@@ -1449,11 +1468,11 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 	if (unlikely(!v))
 		return true;
 
-	if (get_user(event, vhost_used_event(vq))) {
+	if (__get_user(event, vhost_used_event(vq))) {
 		vq_err(vq, "Failed to get used event idx");
 		return true;
 	}
-	return vring_need_event(event, new, old);
+	return vring_need_event(vhost16_to_cpu(vq, event), new, old);
 }
 
 /* This actually signals the guest, using eventfd. */
@@ -1488,7 +1507,7 @@ EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n);
 /* OK, now we need to know about added descriptors. */
 bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 {
-	u16 avail_idx;
+	__virtio16 avail_idx;
 	int r;
 
 	if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY))
@@ -1519,7 +1538,7 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 		return false;
 	}
 
-	return avail_idx != vq->avail_idx;
+	return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx;
 }
 EXPORT_SYMBOL_GPL(vhost_enable_notify);
 
-- 
MST

[PATCH v6 32/46] vhost/net: virtio 1.0 byte swap

[Michael S. Tsirkin]

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/net.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index dce5c58..cae22f9 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -416,7 +416,7 @@ static void handle_tx(struct vhost_net *net)
 			struct ubuf_info *ubuf;
 			ubuf = nvq->ubuf_info + nvq->upend_idx;
 
-			vq->heads[nvq->upend_idx].id = head;
+			vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
 			vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
 			ubuf->callback = vhost_zerocopy_callback;
 			ubuf->ctx = nvq->ubufs;
@@ -500,6 +500,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
 	int headcount = 0;
 	unsigned d;
 	int r, nlogs = 0;
+	u32 len;
 
 	while (datalen > 0 && headcount < quota) {
 		if (unlikely(seg >= UIO_MAXIOV)) {
@@ -527,13 +528,14 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
 			nlogs += *log_num;
 			log += *log_num;
 		}
-		heads[headcount].id = d;
-		heads[headcount].len = iov_length(vq->iov + seg, in);
-		datalen -= heads[headcount].len;
+		heads[headcount].id = cpu_to_vhost32(vq, d);
+		len = iov_length(vq->iov + seg, in);
+		heads[headcount].len = cpu_to_vhost32(vq, len);
+		datalen -= len;
 		++headcount;
 		seg += in;
 	}
-	heads[headcount - 1].len += datalen;
+	heads[headcount - 1].len = cpu_to_vhost32(vq, len - datalen);
 	*iovcount = seg;
 	if (unlikely(log))
 		*log_num = nlogs;
-- 
MST

[PATCH v6 33/46] vhost/net: larger header for virtio 1.0

[Michael S. Tsirkin]

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index cae22f9..1ac58d0 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1027,7 +1027,8 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
 	size_t vhost_hlen, sock_hlen, hdr_len;
 	int i;
 
-	hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
+	hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
+			       (1ULL << VIRTIO_F_VERSION_1))) ?
 			sizeof(struct virtio_net_hdr_mrg_rxbuf) :
 			sizeof(struct virtio_net_hdr);
 	if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
-- 
MST

Re: [PATCH v6 33/46] vhost/net: larger header for virtio 1.0

[Jason Wang]

On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/vhost/net.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index cae22f9..1ac58d0 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -1027,7 +1027,8 @@ static int vhost_net_set_features(struct 
> vhost_net *n, u64 features)
>  	size_t vhost_hlen, sock_hlen, hdr_len;
>  	int i;
>  
> -	hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
> +	hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> +			       (1ULL << VIRTIO_F_VERSION_1))) ?
>  			sizeof(struct virtio_net_hdr_mrg_rxbuf) :
>  			sizeof(struct virtio_net_hdr);
>  	if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
> -- 
> MST
> 

Reviewed-by: Jason Wang <jasowang@redhat.com>

[PATCH v6 34/46] virtio_net: disable mac write for virtio 1.0

[Michael S. Tsirkin]

The spec states that mac in config space is only driver-writable in the
legacy case.  Fence writing it in virtnet_set_mac_address() in the
virtio 1.0 case.

Suggested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/virtio_net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c6a72d3..9ab3c50 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1030,7 +1030,8 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
 				 "Failed to set mac address by vq command.\n");
 			return -EINVAL;
 		}
-	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
+	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
+		   !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
 		unsigned int i;
 
 		/* Naturally, this has an atomicity problem. */
-- 
MST

Re: [PATCH v6 34/46] virtio_net: disable mac write for virtio 1.0

[Jason Wang]

On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> The spec states that mac in config space is only driver-writable in 
> the
> legacy case.  Fence writing it in virtnet_set_mac_address() in the
> virtio 1.0 case.
> 
> Suggested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/net/virtio_net.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index c6a72d3..9ab3c50 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1030,7 +1030,8 @@ static int virtnet_set_mac_address(struct 
> net_device *dev, void *p)
>  				 "Failed to set mac address by vq command.\n");
>  			return -EINVAL;
>  		}
> -	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
> +	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
> +		   !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
>  		unsigned int i;
>  
>  		/* Naturally, this has an atomicity problem. */
> -- 
> MST

Does this mean there's no way to setting mac addres
if ctrl mac addr is disabled in virtio-1?

If yes, we'd better keep this compatibility somehow. 

Re: [PATCH v6 34/46] virtio_net: disable mac write for virtio 1.0

[Michael S. Tsirkin]

On Fri, Nov 28, 2014 at 08:48:24AM +0008, Jason Wang wrote:
> 
> 
> On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst@redhat.com> wrote:
> >The spec states that mac in config space is only driver-writable in the
> >legacy case.  Fence writing it in virtnet_set_mac_address() in the
> >virtio 1.0 case.
> >
> >Suggested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> >Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> >---
> > drivers/net/virtio_net.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> >diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> >index c6a72d3..9ab3c50 100644
> >--- a/drivers/net/virtio_net.c
> >+++ b/drivers/net/virtio_net.c
> >@@ -1030,7 +1030,8 @@ static int virtnet_set_mac_address(struct net_device
> >*dev, void *p)
> > 				 "Failed to set mac address by vq command.\n");
> > 			return -EINVAL;
> > 		}
> >-	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
> >+	} else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC) &&
> >+		   !virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
> > 		unsigned int i;
> > 		/* Naturally, this has an atomicity problem. */
> >-- 
> >MST
> 
> Does this mean there's no way to setting mac addres
> if ctrl mac addr is disabled in virtio-1?

More exactly: no way for host to know the guest mac address.

> If yes, we'd better keep this compatibility somehow.

If host wants to be notified about guest mac updates,
it must enable the appropriate ctrl command.
Or if it's an old host, it just doesn't enable virtio-1.

There's no way around this - it's in the spec.


-- 
MST

[PATCH v6 35/46] vhost/net: enable virtio 1.0

[Michael S. Tsirkin]

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 1ac58d0..984242e 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -61,7 +61,8 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
 enum {
 	VHOST_NET_FEATURES = VHOST_FEATURES |
 			 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
-			 (1ULL << VIRTIO_NET_F_MRG_RXBUF),
+			 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
+			 (1ULL << VIRTIO_F_VERSION_1),
 };
 
 enum {
-- 
MST

[PATCH v6 36/46] vhost/net: suppress compiler warning

[Michael S. Tsirkin]

len is always initialized since function is called with size > 0.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 984242e..54ffbb0 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -501,7 +501,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
 	int headcount = 0;
 	unsigned d;
 	int r, nlogs = 0;
-	u32 len;
+	u32 uninitialized_var(len);
 
 	while (datalen > 0 && headcount < quota) {
 		if (unlikely(seg >= UIO_MAXIOV)) {
-- 
MST

[PATCH v6 37/46] tun: move internal flag defines out of uapi

[Michael S. Tsirkin]

TUN_ flags are internal and never exposed
to userspace. Any application using it is almost
certainly buggy.

Move them out to tun.c, we'll remove them in follow-up patches.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/uapi/linux/if_tun.h | 16 ++--------
 drivers/net/tun.c           | 74 ++++++++++++++-------------------------------
 2 files changed, 26 insertions(+), 64 deletions(-)

diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h
index e9502dd..277a260 100644
--- a/include/uapi/linux/if_tun.h
+++ b/include/uapi/linux/if_tun.h
@@ -22,21 +22,11 @@
 
 /* Read queue size */
 #define TUN_READQ_SIZE	500
-
-/* TUN device flags */
-#define TUN_TUN_DEV 	0x0001	
-#define TUN_TAP_DEV	0x0002
+/* TUN device type flags: deprecated. Use IFF_TUN/IFF_TAP instead. */
+#define TUN_TUN_DEV 	IFF_TUN
+#define TUN_TAP_DEV	IFF_TAP
 #define TUN_TYPE_MASK   0x000f
 
-#define TUN_FASYNC	0x0010
-#define TUN_NOCHECKSUM	0x0020
-#define TUN_NO_PI	0x0040
-/* This flag has no real effect */
-#define TUN_ONE_QUEUE	0x0080
-#define TUN_PERSIST 	0x0100	
-#define TUN_VNET_HDR 	0x0200
-#define TUN_TAP_MQ      0x0400
-
 /* Ioctl defines */
 #define TUNSETNOCSUM  _IOW('T', 200, int) 
 #define TUNSETDEBUG   _IOW('T', 201, int) 
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 9dd3746..bc89d07 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -103,6 +103,21 @@ do {								\
 } while (0)
 #endif
 
+/* TUN device flags */
+
+/* IFF_ATTACH_QUEUE is never stored in device flags,
+ * overload it to mean fasync when stored there.
+ */
+#define TUN_FASYNC	IFF_ATTACH_QUEUE
+#define TUN_NO_PI	IFF_NO_PI
+/* This flag has no real effect */
+#define TUN_ONE_QUEUE	IFF_ONE_QUEUE
+#define TUN_PERSIST 	IFF_PERSIST
+#define TUN_VNET_HDR 	IFF_VNET_HDR
+#define TUN_TAP_MQ      IFF_MULTI_QUEUE
+
+#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
+		      IFF_MULTI_QUEUE)
 #define GOODCOPY_LEN 128
 
 #define FLT_EXACT_COUNT 8
@@ -1521,32 +1536,7 @@ static struct proto tun_proto = {
 
 static int tun_flags(struct tun_struct *tun)
 {
-	int flags = 0;
-
-	if (tun->flags & TUN_TUN_DEV)
-		flags |= IFF_TUN;
-	else
-		flags |= IFF_TAP;
-
-	if (tun->flags & TUN_NO_PI)
-		flags |= IFF_NO_PI;
-
-	/* This flag has no real effect.  We track the value for backwards
-	 * compatibility.
-	 */
-	if (tun->flags & TUN_ONE_QUEUE)
-		flags |= IFF_ONE_QUEUE;
-
-	if (tun->flags & TUN_VNET_HDR)
-		flags |= IFF_VNET_HDR;
-
-	if (tun->flags & TUN_TAP_MQ)
-		flags |= IFF_MULTI_QUEUE;
-
-	if (tun->flags & TUN_PERSIST)
-		flags |= IFF_PERSIST;
-
-	return flags;
+	return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
 }
 
 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
@@ -1706,28 +1696,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 
 	tun_debug(KERN_INFO, tun, "tun_set_iff\n");
 
-	if (ifr->ifr_flags & IFF_NO_PI)
-		tun->flags |= TUN_NO_PI;
-	else
-		tun->flags &= ~TUN_NO_PI;
-
-	/* This flag has no real effect.  We track the value for backwards
-	 * compatibility.
-	 */
-	if (ifr->ifr_flags & IFF_ONE_QUEUE)
-		tun->flags |= TUN_ONE_QUEUE;
-	else
-		tun->flags &= ~TUN_ONE_QUEUE;
-
-	if (ifr->ifr_flags & IFF_VNET_HDR)
-		tun->flags |= TUN_VNET_HDR;
-	else
-		tun->flags &= ~TUN_VNET_HDR;
-
-	if (ifr->ifr_flags & IFF_MULTI_QUEUE)
-		tun->flags |= TUN_TAP_MQ;
-	else
-		tun->flags &= ~TUN_TAP_MQ;
+	tun->flags = (tun->flags & ~TUN_FEATURES) |
+		(ifr->ifr_flags & TUN_FEATURES);
 
 	/* Make sure persistent devices do not get stuck in
 	 * xoff state.
@@ -1890,9 +1860,11 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 	if (cmd == TUNGETFEATURES) {
 		/* Currently this just means: "what IFF flags are valid?".
 		 * This is needed because we never checked for invalid flags on
-		 * TUNSETIFF. */
-		return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
-				IFF_VNET_HDR | IFF_MULTI_QUEUE,
+		 * TUNSETIFF.  Why do we report IFF_TUN and IFF_TAP which are
+		 * not legal for TUNSETIFF here?  It's probably a bug, but it
+		 * doesn't seem to be worth fixing.
+		 */
+		return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
 				(unsigned int __user*)argp);
 	} else if (cmd == TUNSETQUEUE)
 		return tun_set_queue(file, &ifr);
-- 
MST

Re: [PATCH v6 37/46] tun: move internal flag defines out of uapi

[Jason Wang]

On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 
wrote:
> TUN_ flags are internal and never exposed
> to userspace. Any application using it is almost
> certainly buggy.
> 
> Move them out to tun.c, we'll remove them in follow-up patches.
> 
> Signed-off-by: Michael S. Tsirkin <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  include/uapi/linux/if_tun.h | 16 ++--------
>  drivers/net/tun.c           | 74 
> ++++++++++++++-------------------------------
>  2 files changed, 26 insertions(+), 64 deletions(-)
> 
> diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h
> index e9502dd..277a260 100644
> --- a/include/uapi/linux/if_tun.h
> +++ b/include/uapi/linux/if_tun.h
> @@ -22,21 +22,11 @@
>  
>  /* Read queue size */
>  #define TUN_READQ_SIZE	500
> -
> -/* TUN device flags */
> -#define TUN_TUN_DEV 	0x0001	
> -#define TUN_TAP_DEV	0x0002
> +/* TUN device type flags: deprecated. Use IFF_TUN/IFF_TAP instead. */
> +#define TUN_TUN_DEV 	IFF_TUN
> +#define TUN_TAP_DEV	IFF_TAP
>  #define TUN_TYPE_MASK   0x000f
>  
> -#define TUN_FASYNC	0x0010
> -#define TUN_NOCHECKSUM	0x0020
> -#define TUN_NO_PI	0x0040
> -/* This flag has no real effect */
> -#define TUN_ONE_QUEUE	0x0080
> -#define TUN_PERSIST 	0x0100	
> -#define TUN_VNET_HDR 	0x0200
> -#define TUN_TAP_MQ      0x0400
> -
>  /* Ioctl defines */
>  #define TUNSETNOCSUM  _IOW('T', 200, int) 
>  #define TUNSETDEBUG   _IOW('T', 201, int) 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index 9dd3746..bc89d07 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -103,6 +103,21 @@ do {								\
>  } while (0)
>  #endif
>  
> +/* TUN device flags */
> +
> +/* IFF_ATTACH_QUEUE is never stored in device flags,
> + * overload it to mean fasync when stored there.
> + */
> +#define TUN_FASYNC	IFF_ATTACH_QUEUE
> +#define TUN_NO_PI	IFF_NO_PI
> +/* This flag has no real effect */
> +#define TUN_ONE_QUEUE	IFF_ONE_QUEUE
> +#define TUN_PERSIST 	IFF_PERSIST
> +#define TUN_VNET_HDR 	IFF_VNET_HDR
> +#define TUN_TAP_MQ      IFF_MULTI_QUEUE
> +
> +#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
> +		      IFF_MULTI_QUEUE)
>  #define GOODCOPY_LEN 128
>  
>  #define FLT_EXACT_COUNT 8
> @@ -1521,32 +1536,7 @@ static struct proto tun_proto = {
>  
>  static int tun_flags(struct tun_struct *tun)
>  {
> -	int flags = 0;
> -
> -	if (tun->flags & TUN_TUN_DEV)
> -		flags |= IFF_TUN;
> -	else
> -		flags |= IFF_TAP;
> -
> -	if (tun->flags & TUN_NO_PI)
> -		flags |= IFF_NO_PI;
> -
> -	/* This flag has no real effect.  We track the value for backwards
> -	 * compatibility.
> -	 */
> -	if (tun->flags & TUN_ONE_QUEUE)
> -		flags |= IFF_ONE_QUEUE;
> -
> -	if (tun->flags & TUN_VNET_HDR)
> -		flags |= IFF_VNET_HDR;
> -
> -	if (tun->flags & TUN_TAP_MQ)
> -		flags |= IFF_MULTI_QUEUE;
> -
> -	if (tun->flags & TUN_PERSIST)
> -		flags |= IFF_PERSIST;
> -
> -	return flags;
> +	return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | 
> IFF_TAP);
>  }
>  
>  static ssize_t tun_show_flags(struct device *dev, struct 
> device_attribute *attr,
> @@ -1706,28 +1696,8 @@ static int tun_set_iff(struct net *net, struct 
> file *file, struct ifreq *ifr)
>  
>  	tun_debug(KERN_INFO, tun, "tun_set_iff\n");
>  
> -	if (ifr->ifr_flags & IFF_NO_PI)
> -		tun->flags |= TUN_NO_PI;
> -	else
> -		tun->flags &= ~TUN_NO_PI;
> -
> -	/* This flag has no real effect.  We track the value for backwards
> -	 * compatibility.
> -	 */
> -	if (ifr->ifr_flags & IFF_ONE_QUEUE)
> -		tun->flags |= TUN_ONE_QUEUE;
> -	else
> -		tun->flags &= ~TUN_ONE_QUEUE;
> -
> -	if (ifr->ifr_flags & IFF_VNET_HDR)
> -		tun->flags |= TUN_VNET_HDR;
> -	else
> -		tun->flags &= ~TUN_VNET_HDR;
> -
> -	if (ifr->ifr_flags & IFF_MULTI_QUEUE)
> -		tun->flags |= TUN_TAP_MQ;
> -	else
> -		tun->flags &= ~TUN_TAP_MQ;
> +	tun->flags = (tun->flags & ~TUN_FEATURES) |
> +		(ifr->ifr_flags & TUN_FEATURES);
>  
>  	/* Make sure persistent devices do not get stuck in
>  	 * xoff state.
> @@ -1890,9 +1860,11 @@ static long __tun_chr_ioctl(struct file *file, 
> unsigned int cmd,
>  	if (cmd == TUNGETFEATURES) {
>  		/* Currently this just means: "what IFF flags are valid?".
>  		 * This is needed because we never checked for invalid flags on
> -		 * TUNSETIFF. */
> -		return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
> -				IFF_VNET_HDR | IFF_MULTI_QUEUE,
> +		 * TUNSETIFF.  Why do we report IFF_TUN and IFF_TAP which are
> +		 * not legal for TUNSETIFF here?  It's probably a bug, but it
> +		 * doesn't seem to be worth fixing.
> +		 */

The question is not very clear. IFF_TUN and IFF_TAP are legal for 
 ifr.ifr_flags during TUNSETIFF. No?
> 
> +		return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
>  				(unsigned int __user*)argp);
>  	} else if (cmd == TUNSETQUEUE)
>  		return tun_set_queue(file, &ifr);
> -- 
> MST
> 
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v6 37/46] tun: move internal flag defines out of uapi

[Michael S. Tsirkin]

On Fri, Nov 28, 2014 at 08:15:32AM +0008, Jason Wang wrote:
> 
> 
> On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> >TUN_ flags are internal and never exposed
> >to userspace. Any application using it is almost
> >certainly buggy.
> >
> >Move them out to tun.c, we'll remove them in follow-up patches.
> >
> >Signed-off-by: Michael S. Tsirkin <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> >---
> > include/uapi/linux/if_tun.h | 16 ++--------
> > drivers/net/tun.c           | 74
> >++++++++++++++-------------------------------
> > 2 files changed, 26 insertions(+), 64 deletions(-)
> >
> >diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h
> >index e9502dd..277a260 100644
> >--- a/include/uapi/linux/if_tun.h
> >+++ b/include/uapi/linux/if_tun.h
> >@@ -22,21 +22,11 @@
> > /* Read queue size */
> > #define TUN_READQ_SIZE	500
> >-
> >-/* TUN device flags */
> >-#define TUN_TUN_DEV 	0x0001	
> >-#define TUN_TAP_DEV	0x0002
> >+/* TUN device type flags: deprecated. Use IFF_TUN/IFF_TAP instead. */
> >+#define TUN_TUN_DEV 	IFF_TUN
> >+#define TUN_TAP_DEV	IFF_TAP
> > #define TUN_TYPE_MASK   0x000f
> >-#define TUN_FASYNC	0x0010
> >-#define TUN_NOCHECKSUM	0x0020
> >-#define TUN_NO_PI	0x0040
> >-/* This flag has no real effect */
> >-#define TUN_ONE_QUEUE	0x0080
> >-#define TUN_PERSIST 	0x0100	
> >-#define TUN_VNET_HDR 	0x0200
> >-#define TUN_TAP_MQ      0x0400
> >-
> > /* Ioctl defines */
> > #define TUNSETNOCSUM  _IOW('T', 200, int)  #define TUNSETDEBUG
> >_IOW('T', 201, int) diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> >index 9dd3746..bc89d07 100644
> >--- a/drivers/net/tun.c
> >+++ b/drivers/net/tun.c
> >@@ -103,6 +103,21 @@ do {								\
> > } while (0)
> > #endif
> >+/* TUN device flags */
> >+
> >+/* IFF_ATTACH_QUEUE is never stored in device flags,
> >+ * overload it to mean fasync when stored there.
> >+ */
> >+#define TUN_FASYNC	IFF_ATTACH_QUEUE
> >+#define TUN_NO_PI	IFF_NO_PI
> >+/* This flag has no real effect */
> >+#define TUN_ONE_QUEUE	IFF_ONE_QUEUE
> >+#define TUN_PERSIST 	IFF_PERSIST
> >+#define TUN_VNET_HDR 	IFF_VNET_HDR
> >+#define TUN_TAP_MQ      IFF_MULTI_QUEUE
> >+
> >+#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
> >+		      IFF_MULTI_QUEUE)
> > #define GOODCOPY_LEN 128
> > #define FLT_EXACT_COUNT 8
> >@@ -1521,32 +1536,7 @@ static struct proto tun_proto = {
> > static int tun_flags(struct tun_struct *tun)
> > {
> >-	int flags = 0;
> >-
> >-	if (tun->flags & TUN_TUN_DEV)
> >-		flags |= IFF_TUN;
> >-	else
> >-		flags |= IFF_TAP;
> >-
> >-	if (tun->flags & TUN_NO_PI)
> >-		flags |= IFF_NO_PI;
> >-
> >-	/* This flag has no real effect.  We track the value for backwards
> >-	 * compatibility.
> >-	 */
> >-	if (tun->flags & TUN_ONE_QUEUE)
> >-		flags |= IFF_ONE_QUEUE;
> >-
> >-	if (tun->flags & TUN_VNET_HDR)
> >-		flags |= IFF_VNET_HDR;
> >-
> >-	if (tun->flags & TUN_TAP_MQ)
> >-		flags |= IFF_MULTI_QUEUE;
> >-
> >-	if (tun->flags & TUN_PERSIST)
> >-		flags |= IFF_PERSIST;
> >-
> >-	return flags;
> >+	return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
> > }
> >   static ssize_t tun_show_flags(struct device *dev, struct
> >device_attribute *attr,
> >@@ -1706,28 +1696,8 @@ static int tun_set_iff(struct net *net, struct file
> >*file, struct ifreq *ifr)
> > 	tun_debug(KERN_INFO, tun, "tun_set_iff\n");
> >-	if (ifr->ifr_flags & IFF_NO_PI)
> >-		tun->flags |= TUN_NO_PI;
> >-	else
> >-		tun->flags &= ~TUN_NO_PI;
> >-
> >-	/* This flag has no real effect.  We track the value for backwards
> >-	 * compatibility.
> >-	 */
> >-	if (ifr->ifr_flags & IFF_ONE_QUEUE)
> >-		tun->flags |= TUN_ONE_QUEUE;
> >-	else
> >-		tun->flags &= ~TUN_ONE_QUEUE;
> >-
> >-	if (ifr->ifr_flags & IFF_VNET_HDR)
> >-		tun->flags |= TUN_VNET_HDR;
> >-	else
> >-		tun->flags &= ~TUN_VNET_HDR;
> >-
> >-	if (ifr->ifr_flags & IFF_MULTI_QUEUE)
> >-		tun->flags |= TUN_TAP_MQ;
> >-	else
> >-		tun->flags &= ~TUN_TAP_MQ;
> >+	tun->flags = (tun->flags & ~TUN_FEATURES) |
> >+		(ifr->ifr_flags & TUN_FEATURES);
> > 	/* Make sure persistent devices do not get stuck in
> > 	 * xoff state.
> >@@ -1890,9 +1860,11 @@ static long __tun_chr_ioctl(struct file *file,
> >unsigned int cmd,
> > 	if (cmd == TUNGETFEATURES) {
> > 		/* Currently this just means: "what IFF flags are valid?".
> > 		 * This is needed because we never checked for invalid flags on
> >-		 * TUNSETIFF. */
> >-		return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
> >-				IFF_VNET_HDR | IFF_MULTI_QUEUE,
> >+		 * TUNSETIFF.  Why do we report IFF_TUN and IFF_TAP which are
> >+		 * not legal for TUNSETIFF here?  It's probably a bug, but it
> >+		 * doesn't seem to be worth fixing.
> >+		 */
> 
> The question is not very clear. IFF_TUN and IFF_TAP are legal for
> ifr.ifr_flags during TUNSETIFF. No?


Absolutely. I'm not sure what I meant anymore. I will drop this chunk -
either by replacing this patch if I have to post another version, or
by a separate patch if I don't.

> >
> >+		return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
> > 				(unsigned int __user*)argp);
> > 	} else if (cmd == TUNSETQUEUE)
> > 		return tun_set_queue(file, &ifr);
> >-- 
> >MST
> >
> >--
> >To unsubscribe from this list: send the line "unsubscribe netdev" in
> >the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> >More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH v6 38/46] tun: drop most type defines

[Michael S. Tsirkin]

It's just as easy to use IFF_ flags directly,
there's no point in adding our own defines.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/tun.c | 62 +++++++++++++++++++++++++------------------------------
 1 file changed, 28 insertions(+), 34 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index bc89d07..61c000c 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -109,12 +109,6 @@ do {								\
  * overload it to mean fasync when stored there.
  */
 #define TUN_FASYNC	IFF_ATTACH_QUEUE
-#define TUN_NO_PI	IFF_NO_PI
-/* This flag has no real effect */
-#define TUN_ONE_QUEUE	IFF_ONE_QUEUE
-#define TUN_PERSIST 	IFF_PERSIST
-#define TUN_VNET_HDR 	IFF_VNET_HDR
-#define TUN_TAP_MQ      IFF_MULTI_QUEUE
 
 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
 		      IFF_MULTI_QUEUE)
@@ -487,7 +481,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
 		if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
 			netif_carrier_off(tun->dev);
 
-			if (!(tun->flags & TUN_PERSIST) &&
+			if (!(tun->flags & IFF_PERSIST) &&
 			    tun->dev->reg_state == NETREG_REGISTERED)
 				unregister_netdevice(tun->dev);
 		}
@@ -538,7 +532,7 @@ static void tun_detach_all(struct net_device *dev)
 	}
 	BUG_ON(tun->numdisabled != 0);
 
-	if (tun->flags & TUN_PERSIST)
+	if (tun->flags & IFF_PERSIST)
 		module_put(THIS_MODULE);
 }
 
@@ -556,7 +550,7 @@ static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filte
 		goto out;
 
 	err = -EBUSY;
-	if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
+	if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
 		goto out;
 
 	err = -E2BIG;
@@ -935,7 +929,7 @@ static void tun_net_init(struct net_device *dev)
 	struct tun_struct *tun = netdev_priv(dev);
 
 	switch (tun->flags & TUN_TYPE_MASK) {
-	case TUN_TUN_DEV:
+	case IFF_TUN:
 		dev->netdev_ops = &tun_netdev_ops;
 
 		/* Point-to-Point TUN Device */
@@ -949,7 +943,7 @@ static void tun_net_init(struct net_device *dev)
 		dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 		break;
 
-	case TUN_TAP_DEV:
+	case IFF_TAP:
 		dev->netdev_ops = &tap_netdev_ops;
 		/* Ethernet TAP Device */
 		ether_setup(dev);
@@ -1040,7 +1034,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	int err;
 	u32 rxhash;
 
-	if (!(tun->flags & TUN_NO_PI)) {
+	if (!(tun->flags & IFF_NO_PI)) {
 		if (len < sizeof(pi))
 			return -EINVAL;
 		len -= sizeof(pi);
@@ -1050,7 +1044,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 		offset += sizeof(pi);
 	}
 
-	if (tun->flags & TUN_VNET_HDR) {
+	if (tun->flags & IFF_VNET_HDR) {
 		if (len < tun->vnet_hdr_sz)
 			return -EINVAL;
 		len -= tun->vnet_hdr_sz;
@@ -1067,7 +1061,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 		offset += tun->vnet_hdr_sz;
 	}
 
-	if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
+	if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
 		align += NET_IP_ALIGN;
 		if (unlikely(len < ETH_HLEN ||
 			     (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
@@ -1130,8 +1124,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	}
 
 	switch (tun->flags & TUN_TYPE_MASK) {
-	case TUN_TUN_DEV:
-		if (tun->flags & TUN_NO_PI) {
+	case IFF_TUN:
+		if (tun->flags & IFF_NO_PI) {
 			switch (skb->data[0] & 0xf0) {
 			case 0x40:
 				pi.proto = htons(ETH_P_IP);
@@ -1150,7 +1144,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 		skb->protocol = pi.proto;
 		skb->dev = tun->dev;
 		break;
-	case TUN_TAP_DEV:
+	case IFF_TAP:
 		skb->protocol = eth_type_trans(skb, tun->dev);
 		break;
 	}
@@ -1256,10 +1250,10 @@ static ssize_t tun_put_user(struct tun_struct *tun,
 	if (vlan_tx_tag_present(skb))
 		vlan_hlen = VLAN_HLEN;
 
-	if (tun->flags & TUN_VNET_HDR)
+	if (tun->flags & IFF_VNET_HDR)
 		vnet_hdr_sz = tun->vnet_hdr_sz;
 
-	if (!(tun->flags & TUN_NO_PI)) {
+	if (!(tun->flags & IFF_NO_PI)) {
 		if ((len -= sizeof(pi)) < 0)
 			return -EINVAL;
 
@@ -1592,7 +1586,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 			return -EINVAL;
 
 		if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
-		    !!(tun->flags & TUN_TAP_MQ))
+		    !!(tun->flags & IFF_MULTI_QUEUE))
 			return -EINVAL;
 
 		if (tun_not_capable(tun))
@@ -1605,7 +1599,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		if (err < 0)
 			return err;
 
-		if (tun->flags & TUN_TAP_MQ &&
+		if (tun->flags & IFF_MULTI_QUEUE &&
 		    (tun->numqueues + tun->numdisabled > 1)) {
 			/* One or more queue has already been attached, no need
 			 * to initialize the device again.
@@ -1628,11 +1622,11 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		/* Set dev type */
 		if (ifr->ifr_flags & IFF_TUN) {
 			/* TUN device */
-			flags |= TUN_TUN_DEV;
+			flags |= IFF_TUN;
 			name = "tun%d";
 		} else if (ifr->ifr_flags & IFF_TAP) {
 			/* TAP device */
-			flags |= TUN_TAP_DEV;
+			flags |= IFF_TAP;
 			name = "tap%d";
 		} else
 			return -EINVAL;
@@ -1825,7 +1819,7 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr)
 		ret = tun_attach(tun, file, false);
 	} else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
 		tun = rtnl_dereference(tfile->tun);
-		if (!tun || !(tun->flags & TUN_TAP_MQ) || tfile->detached)
+		if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
 			ret = -EINVAL;
 		else
 			__tun_detach(tfile, false);
@@ -1931,12 +1925,12 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 		/* Disable/Enable persist mode. Keep an extra reference to the
 		 * module to prevent the module being unprobed.
 		 */
-		if (arg && !(tun->flags & TUN_PERSIST)) {
-			tun->flags |= TUN_PERSIST;
+		if (arg && !(tun->flags & IFF_PERSIST)) {
+			tun->flags |= IFF_PERSIST;
 			__module_get(THIS_MODULE);
 		}
-		if (!arg && (tun->flags & TUN_PERSIST)) {
-			tun->flags &= ~TUN_PERSIST;
+		if (!arg && (tun->flags & IFF_PERSIST)) {
+			tun->flags &= ~IFF_PERSIST;
 			module_put(THIS_MODULE);
 		}
 
@@ -1994,7 +1988,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 	case TUNSETTXFILTER:
 		/* Can be set only for TAPs */
 		ret = -EINVAL;
-		if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
+		if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
 			break;
 		ret = update_filter(&tun->txflt, (void __user *)arg);
 		break;
@@ -2053,7 +2047,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 	case TUNATTACHFILTER:
 		/* Can be set only for TAPs */
 		ret = -EINVAL;
-		if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
+		if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
 			break;
 		ret = -EFAULT;
 		if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
@@ -2065,7 +2059,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 	case TUNDETACHFILTER:
 		/* Can be set only for TAPs */
 		ret = -EINVAL;
-		if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
+		if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
 			break;
 		ret = 0;
 		tun_detach_filter(tun, tun->numqueues);
@@ -2073,7 +2067,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 
 	case TUNGETFILTER:
 		ret = -EINVAL;
-		if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
+		if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
 			break;
 		ret = -EFAULT;
 		if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
@@ -2266,10 +2260,10 @@ static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info
 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
 
 	switch (tun->flags & TUN_TYPE_MASK) {
-	case TUN_TUN_DEV:
+	case IFF_TUN:
 		strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
 		break;
-	case TUN_TAP_DEV:
+	case IFF_TAP:
 		strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
 		break;
 	}
-- 
MST

Re: [PATCH v6 38/46] tun: drop most type defines

[Jason Wang]

On Fri, Nov 28, 2014 at 4:11 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> It's just as easy to use IFF_ flags directly,
> there's no point in adding our own defines.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/net/tun.c | 62 
> +++++++++++++++++++++++++------------------------------
>  1 file changed, 28 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c

Patch looks fine, but I don't see the reason that why not squash patch 
37
into this.

[..]

Re: [PATCH v6 38/46] tun: drop most type defines

[Michael S. Tsirkin]

On Fri, Nov 28, 2014 at 08:17:48AM +0008, Jason Wang wrote:
> 
> 
> On Fri, Nov 28, 2014 at 4:11 AM, Michael S. Tsirkin <mst@redhat.com> wrote:
> >It's just as easy to use IFF_ flags directly,
> >there's no point in adding our own defines.
> >
> >Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> >---
> > drivers/net/tun.c | 62
> >+++++++++++++++++++++++++------------------------------
> > 1 file changed, 28 insertions(+), 34 deletions(-)
> >
> >diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> 
> Patch looks fine, but I don't see the reason that why not squash patch 37
> into this.
> 
> [..]

squashing is always easy, I thought review is easier if at each step
identity to original code can be verified directly.

[PATCH v6 39/46] tun: add VNET_LE flag

[Michael S. Tsirkin]

virtio 1.0 modified virtio net header format,
making all fields little endian.

Users can tweak header format before submitting it to tun,
but this means more data copies where none were necessary.
And if the iovec is in RO memory, this means we might
need to split iovec also means we might in theory overflow
iovec max size.

This patch adds a simpler way for applications to handle this,
using new "little endian" flag in tun.
As a result, tun simply byte-swaps header fields as appropriate.
This is a NOP on LE architectures.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/uapi/linux/if_tun.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h
index 277a260..18b2403 100644
--- a/include/uapi/linux/if_tun.h
+++ b/include/uapi/linux/if_tun.h
@@ -57,6 +57,7 @@
 #define IFF_ONE_QUEUE	0x2000
 #define IFF_VNET_HDR	0x4000
 #define IFF_TUN_EXCL	0x8000
+#define IFF_VNET_LE	0x10000
 #define IFF_MULTI_QUEUE 0x0100
 #define IFF_ATTACH_QUEUE 0x0200
 #define IFF_DETACH_QUEUE 0x0400
-- 
MST

[PATCH v6 40/46] tun: TUN_VNET_LE support, fix sparse warnings for virtio headers

[Michael S. Tsirkin]

Pretty straight-forward: convert all fields to/from
virtio endian-ness.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/tun.c | 48 +++++++++++++++++++++++++++++-------------------
 1 file changed, 29 insertions(+), 19 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 61c000c..f411ffd 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -111,7 +111,7 @@ do {								\
 #define TUN_FASYNC	IFF_ATTACH_QUEUE
 
 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
-		      IFF_MULTI_QUEUE)
+		      IFF_VNET_LE | IFF_MULTI_QUEUE)
 #define GOODCOPY_LEN 128
 
 #define FLT_EXACT_COUNT 8
@@ -205,6 +205,16 @@ struct tun_struct {
 	u32 flow_count;
 };
 
+static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
+{
+	return __virtio16_to_cpu(tun->flags & IFF_VNET_LE, val);
+}
+
+static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
+{
+	return __cpu_to_virtio16(tun->flags & IFF_VNET_LE, val);
+}
+
 static inline u32 tun_hashfn(u32 rxhash)
 {
 	return rxhash & 0x3ff;
@@ -1053,10 +1063,10 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 			return -EFAULT;
 
 		if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
-		    gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
-			gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
+		    tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
+			gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
 
-		if (gso.hdr_len > len)
+		if (tun16_to_cpu(tun, gso.hdr_len) > len)
 			return -EINVAL;
 		offset += tun->vnet_hdr_sz;
 	}
@@ -1064,7 +1074,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
 		align += NET_IP_ALIGN;
 		if (unlikely(len < ETH_HLEN ||
-			     (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
+			     (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
 			return -EINVAL;
 	}
 
@@ -1075,7 +1085,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 		 * enough room for skb expand head in case it is used.
 		 * The rest of the buffer is mapped from userspace.
 		 */
-		copylen = gso.hdr_len ? gso.hdr_len : GOODCOPY_LEN;
+		copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
 		if (copylen > good_linear)
 			copylen = good_linear;
 		linear = copylen;
@@ -1085,10 +1095,10 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 
 	if (!zerocopy) {
 		copylen = len;
-		if (gso.hdr_len > good_linear)
+		if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
 			linear = good_linear;
 		else
-			linear = gso.hdr_len;
+			linear = tun16_to_cpu(tun, gso.hdr_len);
 	}
 
 	skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
@@ -1115,8 +1125,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	}
 
 	if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
-		if (!skb_partial_csum_set(skb, gso.csum_start,
-					  gso.csum_offset)) {
+		if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
+					  tun16_to_cpu(tun, gso.csum_offset))) {
 			tun->dev->stats.rx_frame_errors++;
 			kfree_skb(skb);
 			return -EINVAL;
@@ -1184,7 +1194,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 		if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 			skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 
-		skb_shinfo(skb)->gso_size = gso.gso_size;
+		skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
 		if (skb_shinfo(skb)->gso_size == 0) {
 			tun->dev->stats.rx_frame_errors++;
 			kfree_skb(skb);
@@ -1276,8 +1286,8 @@ static ssize_t tun_put_user(struct tun_struct *tun,
 			struct skb_shared_info *sinfo = skb_shinfo(skb);
 
 			/* This is a hint as to how much should be linear. */
-			gso.hdr_len = skb_headlen(skb);
-			gso.gso_size = sinfo->gso_size;
+			gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
+			gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
 			if (sinfo->gso_type & SKB_GSO_TCPV4)
 				gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 			else if (sinfo->gso_type & SKB_GSO_TCPV6)
@@ -1285,12 +1295,12 @@ static ssize_t tun_put_user(struct tun_struct *tun,
 			else {
 				pr_err("unexpected GSO type: "
 				       "0x%x, gso_size %d, hdr_len %d\n",
-				       sinfo->gso_type, gso.gso_size,
-				       gso.hdr_len);
+				       sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
+				       tun16_to_cpu(tun, gso.hdr_len));
 				print_hex_dump(KERN_ERR, "tun: ",
 					       DUMP_PREFIX_NONE,
 					       16, 1, skb->head,
-					       min((int)gso.hdr_len, 64), true);
+					       min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
 				WARN_ON_ONCE(1);
 				return -EINVAL;
 			}
@@ -1301,9 +1311,9 @@ static ssize_t tun_put_user(struct tun_struct *tun,
 
 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
 			gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-			gso.csum_start = skb_checksum_start_offset(skb) +
-					 vlan_hlen;
-			gso.csum_offset = skb->csum_offset;
+			gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) +
+						      vlan_hlen);
+			gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
 		} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
 			gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
 		} /* else everything is zero */
-- 
MST

Re: [PATCH v6 40/46] tun: TUN_VNET_LE support, fix sparse warnings for virtio headers

[Jason Wang]

On Fri, Nov 28, 2014 at 4:11 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> Pretty straight-forward: convert all fields to/from
> virtio endian-ness.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/net/tun.c | 48 
> +++++++++++++++++++++++++++++-------------------
>  1 file changed, 29 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index 61c000c..f411ffd 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -111,7 +111,7 @@ do {								\
>  #define TUN_FASYNC	IFF_ATTACH_QUEUE
>  
>  #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
> -		      IFF_MULTI_QUEUE)
> +		      IFF_VNET_LE | IFF_MULTI_QUEUE)
>  #define GOODCOPY_LEN 128
>  
>  #define FLT_EXACT_COUNT 8
> @@ -205,6 +205,16 @@ struct tun_struct {
>  	u32 flow_count;
>  };
>  
> +static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 
> val)
> +{
> +	return __virtio16_to_cpu(tun->flags & IFF_VNET_LE, val);
> +}
> +
> +static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 
> val)
> +{
> +	return __cpu_to_virtio16(tun->flags & IFF_VNET_LE, val);
> +}
> +
>  static inline u32 tun_hashfn(u32 rxhash)
>  {
>  	return rxhash & 0x3ff;
> @@ -1053,10 +1063,10 @@ static ssize_t tun_get_user(struct tun_struct 
> *tun, struct tun_file *tfile,
>  			return -EFAULT;
>  
>  		if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
> -		    gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
> -			gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
> +		    tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, 
> gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
> +			gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) 
> + tun16_to_cpu(tun, gso.csum_offset) + 2);
>  
> -		if (gso.hdr_len > len)
> +		if (tun16_to_cpu(tun, gso.hdr_len) > len)
>  			return -EINVAL;
>  		offset += tun->vnet_hdr_sz;
>  	}
> @@ -1064,7 +1074,7 @@ static ssize_t tun_get_user(struct tun_struct 
> *tun, struct tun_file *tfile,
>  	if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
>  		align += NET_IP_ALIGN;
>  		if (unlikely(len < ETH_HLEN ||
> -			     (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
> +			     (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
>  			return -EINVAL;
>  	}
>  
> @@ -1075,7 +1085,7 @@ static ssize_t tun_get_user(struct tun_struct 
> *tun, struct tun_file *tfile,
>  		 * enough room for skb expand head in case it is used.
>  		 * The rest of the buffer is mapped from userspace.
>  		 */
> -		copylen = gso.hdr_len ? gso.hdr_len : GOODCOPY_LEN;
> +		copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : 
> GOODCOPY_LEN;
>  		if (copylen > good_linear)
>  			copylen = good_linear;
>  		linear = copylen;
> @@ -1085,10 +1095,10 @@ static ssize_t tun_get_user(struct tun_struct 
> *tun, struct tun_file *tfile,
>  
>  	if (!zerocopy) {
>  		copylen = len;
> -		if (gso.hdr_len > good_linear)
> +		if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
>  			linear = good_linear;
>  		else
> -			linear = gso.hdr_len;
> +			linear = tun16_to_cpu(tun, gso.hdr_len);
>  	}
>  
>  	skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
> @@ -1115,8 +1125,8 @@ static ssize_t tun_get_user(struct tun_struct 
> *tun, struct tun_file *tfile,
>  	}
>  
>  	if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
> -		if (!skb_partial_csum_set(skb, gso.csum_start,
> -					  gso.csum_offset)) {
> +		if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
> +					  tun16_to_cpu(tun, gso.csum_offset))) {
>  			tun->dev->stats.rx_frame_errors++;
>  			kfree_skb(skb);
>  			return -EINVAL;
> @@ -1184,7 +1194,7 @@ static ssize_t tun_get_user(struct tun_struct 
> *tun, struct tun_file *tfile,
>  		if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
>  			skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
>  
> -		skb_shinfo(skb)->gso_size = gso.gso_size;
> +		skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
>  		if (skb_shinfo(skb)->gso_size == 0) {
>  			tun->dev->stats.rx_frame_errors++;
>  			kfree_skb(skb);
> @@ -1276,8 +1286,8 @@ static ssize_t tun_put_user(struct tun_struct 
> *tun,
>  			struct skb_shared_info *sinfo = skb_shinfo(skb);
>  
>  			/* This is a hint as to how much should be linear. */
> -			gso.hdr_len = skb_headlen(skb);
> -			gso.gso_size = sinfo->gso_size;
> +			gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
> +			gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
>  			if (sinfo->gso_type & SKB_GSO_TCPV4)
>  				gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
>  			else if (sinfo->gso_type & SKB_GSO_TCPV6)
> @@ -1285,12 +1295,12 @@ static ssize_t tun_put_user(struct tun_struct 
> *tun,
>  			else {
>  				pr_err("unexpected GSO type: "
>  				       "0x%x, gso_size %d, hdr_len %d\n",
> -				       sinfo->gso_type, gso.gso_size,
> -				       gso.hdr_len);
> +				       sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
> +				       tun16_to_cpu(tun, gso.hdr_len));
>  				print_hex_dump(KERN_ERR, "tun: ",
>  					       DUMP_PREFIX_NONE,
>  					       16, 1, skb->head,
> -					       min((int)gso.hdr_len, 64), true);
> +					       min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
>  				WARN_ON_ONCE(1);
>  				return -EINVAL;
>  			}
> @@ -1301,9 +1311,9 @@ static ssize_t tun_put_user(struct tun_struct 
> *tun,
>  
>  		if (skb->ip_summed == CHECKSUM_PARTIAL) {
>  			gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
> -			gso.csum_start = skb_checksum_start_offset(skb) +
> -					 vlan_hlen;
> -			gso.csum_offset = skb->csum_offset;
> +			gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) 
> +
> +						      vlan_hlen);
> +			gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
>  		} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
>  			gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
>  		} /* else everything is zero */
> -- 
> MST

Reviewed-by: Jason Wang <jasowang@redhat.com>

[PATCH v6 41/46] macvtap: TUN_VNET_HDR support

[Michael S. Tsirkin]

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/macvtap.c | 68 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 43 insertions(+), 25 deletions(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 880cc09..af90ab5 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -45,6 +45,18 @@ struct macvtap_queue {
 	struct list_head next;
 };
 
+#define MACVTAP_FEATURES (IFF_VNET_HDR | IFF_VNET_LE | IFF_MULTI_QUEUE)
+
+static inline u16 macvtap16_to_cpu(struct macvtap_queue *q, __virtio16 val)
+{
+	return __virtio16_to_cpu(q->flags & IFF_VNET_LE, val);
+}
+
+static inline __virtio16 cpu_to_macvtap16(struct macvtap_queue *q, u16 val)
+{
+	return __cpu_to_virtio16(q->flags & IFF_VNET_LE, val);
+}
+
 static struct proto macvtap_proto = {
 	.name = "macvtap",
 	.owner = THIS_MODULE,
@@ -557,7 +569,8 @@ static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
  * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
  * be shared with the tun/tap driver.
  */
-static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
+static int macvtap_skb_from_vnet_hdr(struct macvtap_queue *q,
+				     struct sk_buff *skb,
 				     struct virtio_net_hdr *vnet_hdr)
 {
 	unsigned short gso_type = 0;
@@ -588,13 +601,13 @@ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
 	}
 
 	if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
-		if (!skb_partial_csum_set(skb, vnet_hdr->csum_start,
-					  vnet_hdr->csum_offset))
+		if (!skb_partial_csum_set(skb, macvtap16_to_cpu(q, vnet_hdr->csum_start),
+					  macvtap16_to_cpu(q, vnet_hdr->csum_offset)))
 			return -EINVAL;
 	}
 
 	if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
-		skb_shinfo(skb)->gso_size = vnet_hdr->gso_size;
+		skb_shinfo(skb)->gso_size = macvtap16_to_cpu(q, vnet_hdr->gso_size);
 		skb_shinfo(skb)->gso_type = gso_type;
 
 		/* Header must be checked, and gso_segs computed. */
@@ -604,8 +617,9 @@ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
 	return 0;
 }
 
-static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
-				   struct virtio_net_hdr *vnet_hdr)
+static void macvtap_skb_to_vnet_hdr(struct macvtap_queue *q,
+				    const struct sk_buff *skb,
+				    struct virtio_net_hdr *vnet_hdr)
 {
 	memset(vnet_hdr, 0, sizeof(*vnet_hdr));
 
@@ -613,8 +627,8 @@ static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
 		struct skb_shared_info *sinfo = skb_shinfo(skb);
 
 		/* This is a hint as to how much should be linear. */
-		vnet_hdr->hdr_len = skb_headlen(skb);
-		vnet_hdr->gso_size = sinfo->gso_size;
+		vnet_hdr->hdr_len = cpu_to_macvtap16(q, skb_headlen(skb));
+		vnet_hdr->gso_size = cpu_to_macvtap16(q, sinfo->gso_size);
 		if (sinfo->gso_type & SKB_GSO_TCPV4)
 			vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 		else if (sinfo->gso_type & SKB_GSO_TCPV6)
@@ -628,10 +642,13 @@ static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-		vnet_hdr->csum_start = skb_checksum_start_offset(skb);
 		if (vlan_tx_tag_present(skb))
-			vnet_hdr->csum_start += VLAN_HLEN;
-		vnet_hdr->csum_offset = skb->csum_offset;
+			vnet_hdr->csum_start = cpu_to_macvtap16(q,
+				skb_checksum_start_offset(skb) + VLAN_HLEN);
+		else
+			vnet_hdr->csum_start = cpu_to_macvtap16(q,
+				skb_checksum_start_offset(skb));
+		vnet_hdr->csum_offset = cpu_to_macvtap16(q, skb->csum_offset);
 	} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
 		vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
 	} /* else everything is zero */
@@ -666,12 +683,14 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 		if (err < 0)
 			goto err;
 		if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
-		     vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
-							vnet_hdr.hdr_len)
-			vnet_hdr.hdr_len = vnet_hdr.csum_start +
-						vnet_hdr.csum_offset + 2;
+		     macvtap16_to_cpu(q, vnet_hdr.csum_start) +
+		     macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2 >
+			     macvtap16_to_cpu(q, vnet_hdr.hdr_len))
+			vnet_hdr.hdr_len = cpu_to_macvtap16(q,
+				 macvtap16_to_cpu(q, vnet_hdr.csum_start) +
+				 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2);
 		err = -EINVAL;
-		if (vnet_hdr.hdr_len > len)
+		if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > len)
 			goto err;
 	}
 
@@ -684,7 +703,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 		goto err;
 
 	if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
-		copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN;
+		copylen = vnet_hdr.hdr_len ?
+			macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN;
 		if (copylen > good_linear)
 			copylen = good_linear;
 		linear = copylen;
@@ -695,10 +715,10 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 
 	if (!zerocopy) {
 		copylen = len;
-		if (vnet_hdr.hdr_len > good_linear)
+		if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > good_linear)
 			linear = good_linear;
 		else
-			linear = vnet_hdr.hdr_len;
+			linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
 	}
 
 	skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen,
@@ -725,7 +745,7 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 	skb->protocol = eth_hdr(skb)->h_proto;
 
 	if (vnet_hdr_len) {
-		err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr);
+		err = macvtap_skb_from_vnet_hdr(q, skb, &vnet_hdr);
 		if (err)
 			goto err_kfree;
 	}
@@ -791,7 +811,7 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
 		if ((len -= vnet_hdr_len) < 0)
 			return -EINVAL;
 
-		macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);
+		macvtap_skb_to_vnet_hdr(q, skb, &vnet_hdr);
 
 		if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
 			return -EFAULT;
@@ -1003,8 +1023,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
 			return -EFAULT;
 
 		ret = 0;
-		if ((u & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
-		    (IFF_NO_PI | IFF_TAP))
+		if ((u & ~MACVTAP_FEATURES) != (IFF_NO_PI | IFF_TAP))
 			ret = -EINVAL;
 		else
 			q->flags = u;
@@ -1036,8 +1055,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
 		return ret;
 
 	case TUNGETFEATURES:
-		if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR |
-			     IFF_MULTI_QUEUE, up))
+		if (put_user(IFF_TAP | IFF_NO_PI | MACVTAP_FEATURES, up))
 			return -EFAULT;
 		return 0;
 
-- 
MST

Re: [PATCH v6 41/46] macvtap: TUN_VNET_HDR support

[Jason Wang]

On Fri, Nov 28, 2014 at 4:11 AM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/net/macvtap.c | 68 
> ++++++++++++++++++++++++++++++++-------------------
>  1 file changed, 43 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
> index 880cc09..af90ab5 100644
> --- a/drivers/net/macvtap.c
> +++ b/drivers/net/macvtap.c
> @@ -45,6 +45,18 @@ struct macvtap_queue {
>  	struct list_head next;
>  };
>  
> +#define MACVTAP_FEATURES (IFF_VNET_HDR | IFF_VNET_LE | 
> IFF_MULTI_QUEUE)
> +
> +static inline u16 macvtap16_to_cpu(struct macvtap_queue *q, 
> __virtio16 val)
> +{
> +	return __virtio16_to_cpu(q->flags & IFF_VNET_LE, val);
> +}
> +
> +static inline __virtio16 cpu_to_macvtap16(struct macvtap_queue *q, 
> u16 val)
> +{
> +	return __cpu_to_virtio16(q->flags & IFF_VNET_LE, val);
> +}
> +
>  static struct proto macvtap_proto = {
>  	.name = "macvtap",
>  	.owner = THIS_MODULE,
> @@ -557,7 +569,8 @@ static inline struct sk_buff 
> *macvtap_alloc_skb(struct sock *sk, size_t prepad,
>   * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
>   * be shared with the tun/tap driver.
>   */
> -static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
> +static int macvtap_skb_from_vnet_hdr(struct macvtap_queue *q,
> +				     struct sk_buff *skb,
>  				     struct virtio_net_hdr *vnet_hdr)
>  {
>  	unsigned short gso_type = 0;
> @@ -588,13 +601,13 @@ static int macvtap_skb_from_vnet_hdr(struct 
> sk_buff *skb,
>  	}
>  
>  	if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
> -		if (!skb_partial_csum_set(skb, vnet_hdr->csum_start,
> -					  vnet_hdr->csum_offset))
> +		if (!skb_partial_csum_set(skb, macvtap16_to_cpu(q, 
> vnet_hdr->csum_start),
> +					  macvtap16_to_cpu(q, vnet_hdr->csum_offset)))
>  			return -EINVAL;
>  	}
>  
>  	if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
> -		skb_shinfo(skb)->gso_size = vnet_hdr->gso_size;
> +		skb_shinfo(skb)->gso_size = macvtap16_to_cpu(q, 
> vnet_hdr->gso_size);
>  		skb_shinfo(skb)->gso_type = gso_type;
>  
>  		/* Header must be checked, and gso_segs computed. */
> @@ -604,8 +617,9 @@ static int macvtap_skb_from_vnet_hdr(struct 
> sk_buff *skb,
>  	return 0;
>  }
>  
> -static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
> -				   struct virtio_net_hdr *vnet_hdr)
> +static void macvtap_skb_to_vnet_hdr(struct macvtap_queue *q,
> +				    const struct sk_buff *skb,
> +				    struct virtio_net_hdr *vnet_hdr)
>  {
>  	memset(vnet_hdr, 0, sizeof(*vnet_hdr));
>  
> @@ -613,8 +627,8 @@ static void macvtap_skb_to_vnet_hdr(const struct 
> sk_buff *skb,
>  		struct skb_shared_info *sinfo = skb_shinfo(skb);
>  
>  		/* This is a hint as to how much should be linear. */
> -		vnet_hdr->hdr_len = skb_headlen(skb);
> -		vnet_hdr->gso_size = sinfo->gso_size;
> +		vnet_hdr->hdr_len = cpu_to_macvtap16(q, skb_headlen(skb));
> +		vnet_hdr->gso_size = cpu_to_macvtap16(q, sinfo->gso_size);
>  		if (sinfo->gso_type & SKB_GSO_TCPV4)
>  			vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
>  		else if (sinfo->gso_type & SKB_GSO_TCPV6)
> @@ -628,10 +642,13 @@ static void macvtap_skb_to_vnet_hdr(const 
> struct sk_buff *skb,
>  
>  	if (skb->ip_summed == CHECKSUM_PARTIAL) {
>  		vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
> -		vnet_hdr->csum_start = skb_checksum_start_offset(skb);
>  		if (vlan_tx_tag_present(skb))
> -			vnet_hdr->csum_start += VLAN_HLEN;
> -		vnet_hdr->csum_offset = skb->csum_offset;
> +			vnet_hdr->csum_start = cpu_to_macvtap16(q,
> +				skb_checksum_start_offset(skb) + VLAN_HLEN);
> +		else
> +			vnet_hdr->csum_start = cpu_to_macvtap16(q,
> +				skb_checksum_start_offset(skb));
> +		vnet_hdr->csum_offset = cpu_to_macvtap16(q, skb->csum_offset);
>  	} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
>  		vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
>  	} /* else everything is zero */
> @@ -666,12 +683,14 @@ static ssize_t macvtap_get_user(struct 
> macvtap_queue *q, struct msghdr *m,
>  		if (err < 0)
>  			goto err;
>  		if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
> -		     vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
> -							vnet_hdr.hdr_len)
> -			vnet_hdr.hdr_len = vnet_hdr.csum_start +
> -						vnet_hdr.csum_offset + 2;
> +		     macvtap16_to_cpu(q, vnet_hdr.csum_start) +
> +		     macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2 >
> +			     macvtap16_to_cpu(q, vnet_hdr.hdr_len))
> +			vnet_hdr.hdr_len = cpu_to_macvtap16(q,
> +				 macvtap16_to_cpu(q, vnet_hdr.csum_start) +
> +				 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2);
>  		err = -EINVAL;
> -		if (vnet_hdr.hdr_len > len)
> +		if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > len)
>  			goto err;
>  	}
>  
> @@ -684,7 +703,8 @@ static ssize_t macvtap_get_user(struct 
> macvtap_queue *q, struct msghdr *m,
>  		goto err;
>  
>  	if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
> -		copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN;
> +		copylen = vnet_hdr.hdr_len ?
> +			macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN;
>  		if (copylen > good_linear)
>  			copylen = good_linear;
>  		linear = copylen;
> @@ -695,10 +715,10 @@ static ssize_t macvtap_get_user(struct 
> macvtap_queue *q, struct msghdr *m,
>  
>  	if (!zerocopy) {
>  		copylen = len;
> -		if (vnet_hdr.hdr_len > good_linear)
> +		if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > good_linear)
>  			linear = good_linear;
>  		else
> -			linear = vnet_hdr.hdr_len;
> +			linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
>  	}
>  
>  	skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen,
> @@ -725,7 +745,7 @@ static ssize_t macvtap_get_user(struct 
> macvtap_queue *q, struct msghdr *m,
>  	skb->protocol = eth_hdr(skb)->h_proto;
>  
>  	if (vnet_hdr_len) {
> -		err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr);
> +		err = macvtap_skb_from_vnet_hdr(q, skb, &vnet_hdr);
>  		if (err)
>  			goto err_kfree;
>  	}
> @@ -791,7 +811,7 @@ static ssize_t macvtap_put_user(struct 
> macvtap_queue *q,
>  		if ((len -= vnet_hdr_len) < 0)
>  			return -EINVAL;
>  
> -		macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);
> +		macvtap_skb_to_vnet_hdr(q, skb, &vnet_hdr);
>  
>  		if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
>  			return -EFAULT;
> @@ -1003,8 +1023,7 @@ static long macvtap_ioctl(struct file *file, 
> unsigned int cmd,
>  			return -EFAULT;
>  
>  		ret = 0;
> -		if ((u & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
> -		    (IFF_NO_PI | IFF_TAP))
> +		if ((u & ~MACVTAP_FEATURES) != (IFF_NO_PI | IFF_TAP))
>  			ret = -EINVAL;
>  		else
>  			q->flags = u;
> @@ -1036,8 +1055,7 @@ static long macvtap_ioctl(struct file *file, 
> unsigned int cmd,
>  		return ret;
>  
>  	case TUNGETFEATURES:
> -		if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR |
> -			     IFF_MULTI_QUEUE, up))
> +		if (put_user(IFF_TAP | IFF_NO_PI | MACVTAP_FEATURES, up))
>  			return -EFAULT;
>  		return 0;
>  
> -- 
> MST

Reviewed-by: Jason Wang <jasowang@redhat.com>

btw, title should be macvtap: IFF_VNET_LE support

[PATCH v6 45/46] vhost/scsi: partial virtio 1.0 support

[Michael S. Tsirkin]

Include all endian conversions as required by virtio 1.0.
Don't set virtio 1.0 yet, since that requires ANY_LAYOUT
which we don't yet support.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
---
 drivers/vhost/scsi.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index a17f118..01c01cb 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -168,6 +168,7 @@ enum {
 	VHOST_SCSI_VQ_IO = 2,
 };
 
+/* Note: can't set VIRTIO_F_VERSION_1 yet, since that implies ANY_LAYOUT. */
 enum {
 	VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG) |
 					       (1ULL << VIRTIO_SCSI_F_T10_PI)
@@ -577,8 +578,8 @@ tcm_vhost_allocate_evt(struct vhost_scsi *vs,
 		return NULL;
 	}
 
-	evt->event.event = event;
-	evt->event.reason = reason;
+	evt->event.event = cpu_to_vhost32(vq, event);
+	evt->event.reason = cpu_to_vhost32(vq, reason);
 	vs->vs_events_nr++;
 
 	return evt;
@@ -636,7 +637,7 @@ again:
 	}
 
 	if (vs->vs_events_missed) {
-		event->event |= VIRTIO_SCSI_T_EVENTS_MISSED;
+		event->event |= cpu_to_vhost32(vq, VIRTIO_SCSI_T_EVENTS_MISSED);
 		vs->vs_events_missed = false;
 	}
 
@@ -695,12 +696,13 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 			cmd, se_cmd->residual_count, se_cmd->scsi_status);
 
 		memset(&v_rsp, 0, sizeof(v_rsp));
-		v_rsp.resid = se_cmd->residual_count;
+		v_rsp.resid = cpu_to_vhost32(cmd->tvc_vq, se_cmd->residual_count);
 		/* TODO is status_qualifier field needed? */
 		v_rsp.status = se_cmd->scsi_status;
-		v_rsp.sense_len = se_cmd->scsi_sense_length;
+		v_rsp.sense_len = cpu_to_vhost32(cmd->tvc_vq,
+						 se_cmd->scsi_sense_length);
 		memcpy(v_rsp.sense, cmd->tvc_sense_buf,
-		       v_rsp.sense_len);
+		       se_cmd->scsi_sense_length);
 		ret = copy_to_user(cmd->tvc_resp, &v_rsp, sizeof(v_rsp));
 		if (likely(ret == 0)) {
 			struct vhost_scsi_virtqueue *q;
@@ -1095,14 +1097,14 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 						", but wrong data_direction\n");
 					goto err_cmd;
 				}
-				prot_bytes = v_req_pi.pi_bytesout;
+				prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
 			} else if (v_req_pi.pi_bytesin) {
 				if (data_direction != DMA_FROM_DEVICE) {
 					vq_err(vq, "Received non zero di_pi_niov"
 						", but wrong data_direction\n");
 					goto err_cmd;
 				}
-				prot_bytes = v_req_pi.pi_bytesin;
+				prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
 			}
 			if (prot_bytes) {
 				int tmp = 0;
@@ -1117,12 +1119,12 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 				data_first += prot_niov;
 				data_niov = data_num - prot_niov;
 			}
-			tag = v_req_pi.tag;
+			tag = vhost64_to_cpu(vq, v_req_pi.tag);
 			task_attr = v_req_pi.task_attr;
 			cdb = &v_req_pi.cdb[0];
 			lun = ((v_req_pi.lun[2] << 8) | v_req_pi.lun[3]) & 0x3FFF;
 		} else {
-			tag = v_req.tag;
+			tag = vhost64_to_cpu(vq, v_req.tag);
 			task_attr = v_req.task_attr;
 			cdb = &v_req.cdb[0];
 			lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
-- 
MST

[PATCH v6 46/46] af_packet: virtio 1.0 stubs

[Michael S. Tsirkin]

This merely fixes sparse warnings, without actually
adding support for the new APIs.

Still working out the best way to enable the new
functionality.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 net/packet/af_packet.c | 35 ++++++++++++++++++++++-------------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 87d20f4..d4a877e 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2444,13 +2444,15 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
 			goto out_unlock;
 
 		if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
-		    (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
-		      vnet_hdr.hdr_len))
-			vnet_hdr.hdr_len = vnet_hdr.csum_start +
-						 vnet_hdr.csum_offset + 2;
+		    (__virtio16_to_cpu(false, vnet_hdr.csum_start) +
+		     __virtio16_to_cpu(false, vnet_hdr.csum_offset) + 2 >
+		      __virtio16_to_cpu(false, vnet_hdr.hdr_len)))
+			vnet_hdr.hdr_len = __cpu_to_virtio16(false,
+				 __virtio16_to_cpu(false, vnet_hdr.csum_start) +
+				__virtio16_to_cpu(false, vnet_hdr.csum_offset) + 2);
 
 		err = -EINVAL;
-		if (vnet_hdr.hdr_len > len)
+		if (__virtio16_to_cpu(false, vnet_hdr.hdr_len) > len)
 			goto out_unlock;
 
 		if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
@@ -2492,7 +2494,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
 	err = -ENOBUFS;
 	hlen = LL_RESERVED_SPACE(dev);
 	tlen = dev->needed_tailroom;
-	skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
+	skb = packet_alloc_skb(sk, hlen + tlen, hlen, len,
+			       __virtio16_to_cpu(false, vnet_hdr.hdr_len),
 			       msg->msg_flags & MSG_DONTWAIT, &err);
 	if (skb == NULL)
 		goto out_unlock;
@@ -2534,14 +2537,16 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
 
 	if (po->has_vnet_hdr) {
 		if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
-			if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
-						  vnet_hdr.csum_offset)) {
+			u16 s = __virtio16_to_cpu(false, vnet_hdr.csum_start);
+			u16 o = __virtio16_to_cpu(false, vnet_hdr.csum_offset);
+			if (!skb_partial_csum_set(skb, s, o)) {
 				err = -EINVAL;
 				goto out_free;
 			}
 		}
 
-		skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
+		skb_shinfo(skb)->gso_size =
+			__virtio16_to_cpu(false, vnet_hdr.gso_size);
 		skb_shinfo(skb)->gso_type = gso_type;
 
 		/* Header must be checked, and gso_segs computed. */
@@ -2912,8 +2917,10 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
 			struct skb_shared_info *sinfo = skb_shinfo(skb);
 
 			/* This is a hint as to how much should be linear. */
-			vnet_hdr.hdr_len = skb_headlen(skb);
-			vnet_hdr.gso_size = sinfo->gso_size;
+			vnet_hdr.hdr_len =
+				__cpu_to_virtio16(false, skb_headlen(skb));
+			vnet_hdr.gso_size =
+				__cpu_to_virtio16(false, sinfo->gso_size);
 			if (sinfo->gso_type & SKB_GSO_TCPV4)
 				vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 			else if (sinfo->gso_type & SKB_GSO_TCPV6)
@@ -2931,8 +2938,10 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
 
 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
 			vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-			vnet_hdr.csum_start = skb_checksum_start_offset(skb);
-			vnet_hdr.csum_offset = skb->csum_offset;
+			vnet_hdr.csum_start = __cpu_to_virtio16(false,
+					  skb_checksum_start_offset(skb));
+			vnet_hdr.csum_offset = __cpu_to_virtio16(false,
+							 skb->csum_offset);
 		} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
 			vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
 		} /* else everything is zero */
-- 
MST