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virtio_net: get rid of virtio_net_hdr/skb_vnet_hdr

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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>
Reviewed-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2014-10-24 16:55:57 +03:00
parent 946fa5647b
commit 012873d057
1 changed files with 41 additions and 49 deletions
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90
drivers/net/virtio_net.c
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@ -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;