Too many places poke at [rs]q->vq->vdev->priv just to get
the the vi structure. Let's just pass the pointer around: seems
cleaner, and might even be faster.
Signed-off-by: Michael S. Tsirkin <[email protected]>
---
drivers/net/virtio_net.c | 36 +++++++++++++++++++-----------------
1 file changed, 19 insertions(+), 17 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 57cbc7d..36f3dfc 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;
@@ -459,9 +461,9 @@ 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);
+ skb = receive_small(vi, buf, len);
if (unlikely(!skb))
return;
@@ -530,9 +532,9 @@ 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;
@@ -655,9 +657,9 @@ 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;
@@ -668,7 +670,7 @@ 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)
@@ -717,7 +719,7 @@ 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
@@ -736,12 +738,12 @@ 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);
}
@@ -817,7 +819,7 @@ 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]);
}
--
MST
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 <[email protected]>
---
drivers/net/virtio_net.c | 88 ++++++++++++++++++++++--------------------------
1 file changed, 40 insertions(+), 48 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 36f3dfc..a795a23 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);
@@ -536,7 +530,7 @@ 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);
@@ -547,7 +541,7 @@ 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);
@@ -557,7 +551,8 @@ 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;
@@ -588,8 +583,8 @@ 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);
@@ -668,7 +663,7 @@ 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);
@@ -848,18 +843,14 @@ 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)) &&
@@ -867,7 +858,7 @@ 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);
@@ -902,7 +893,7 @@ 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) {
@@ -1773,18 +1764,19 @@ 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
With VERSION_1 virtio_net uses same header size
whether mergeable buffers are enabled or not.
Signed-off-by: Michael S. Tsirkin <[email protected]>
---
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 9c6d50f..a2fe340 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1764,7 +1764,8 @@ 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
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 <[email protected]>
---
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 a795a23..9c6d50f 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
From: Michael S. Tsirkin
> Too many places poke at [rs]q->vq->vdev->priv just to get
> the the vi structure. Let's just pass the pointer around: seems
> cleaner, and might even be faster.
>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
> ---
> drivers/net/virtio_net.c | 36 +++++++++++++++++++-----------------
> 1 file changed, 19 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 57cbc7d..36f3dfc 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
...
> static struct sk_buff *receive_big(struct net_device *dev,
> + struct virtnet_info *vi,
Do you need to pass 'dev' here?
Looks like it is obtainable from vi->dev (as below).
David
> 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);
...
> -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;
...
On Fri, Oct 24, 2014 at 10:02:15AM +0000, David Laight wrote:
> From: Michael S. Tsirkin
>
> > Too many places poke at [rs]q->vq->vdev->priv just to get
> > the the vi structure. Let's just pass the pointer around: seems
> > cleaner, and might even be faster.
> >
> > Signed-off-by: Michael S. Tsirkin <[email protected]>
> > ---
> > drivers/net/virtio_net.c | 36 +++++++++++++++++++-----------------
> > 1 file changed, 19 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 57cbc7d..36f3dfc 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> ...
> > static struct sk_buff *receive_big(struct net_device *dev,
> > + struct virtnet_info *vi,
>
> Do you need to pass 'dev' here?
> Looks like it is obtainable from vi->dev (as below).
>
> David
>
> > 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);
> ...
> > -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;
> ...
It's a matter of style, isn't it?
We have dev to hand, it seems cleaner to just pass it around.
--
MST
"Michael S. Tsirkin" <[email protected]> writes:
> Too many places poke at [rs]q->vq->vdev->priv just to get
> the the vi structure. Let's just pass the pointer around: seems
> cleaner, and might even be faster.
Agreed, it's neater.
Acked-by: Rusty Russell <[email protected]>
Thanks,
Rusty.
>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
> ---
> drivers/net/virtio_net.c | 36 +++++++++++++++++++-----------------
> 1 file changed, 19 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 57cbc7d..36f3dfc 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;
> @@ -459,9 +461,9 @@ 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);
> + skb = receive_small(vi, buf, len);
>
> if (unlikely(!skb))
> return;
> @@ -530,9 +532,9 @@ 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;
> @@ -655,9 +657,9 @@ 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;
>
> @@ -668,7 +670,7 @@ 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)
> @@ -717,7 +719,7 @@ 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
> @@ -736,12 +738,12 @@ 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);
> }
>
> @@ -817,7 +819,7 @@ 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]);
> }
> --
> MST
"Michael S. Tsirkin" <[email protected]> writes:
> 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.
Yes, this is definitely a win.
Acked-by: Rusty Russell <[email protected]>
Thanks,
Rusty.
>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
> ---
> drivers/net/virtio_net.c | 88 ++++++++++++++++++++++--------------------------
> 1 file changed, 40 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 36f3dfc..a795a23 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);
> @@ -536,7 +530,7 @@ 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);
> @@ -547,7 +541,7 @@ 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);
> @@ -557,7 +551,8 @@ 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;
> @@ -588,8 +583,8 @@ 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);
> @@ -668,7 +663,7 @@ 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);
>
> @@ -848,18 +843,14 @@ 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)) &&
> @@ -867,7 +858,7 @@ 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);
>
> @@ -902,7 +893,7 @@ 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) {
> @@ -1773,18 +1764,19 @@ 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
"Michael S. Tsirkin" <[email protected]> writes:
> With VERSION_1 virtio_net uses same header size
> whether mergeable buffers are enabled or not.
>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
These two are great too, thanks:
Acked-by: Rusty Russell <[email protected]>
Cheers,
Rusty.
> ---
> 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 9c6d50f..a2fe340 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1764,7 +1764,8 @@ 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