This patch series has 2 patches.
Patch 1/2: keep vnet header zeroed if XDP is loaded for small buffer
With this fix, we do not need to care about vnet header in XDP meta data
support for small buffer, even though XDP meta data uses in front of
packet as same as vnet header.
It would be best if this patch goes into stable.
This patch is based on the feedback by Jason Wang and Michael S. Tsirkin.
https://lore.kernel.org/netdev/[email protected]/
https://lore.kernel.org/netdev/[email protected]/
Patch 2/2: add XDP meta data support
Thanks to Jason Wang, Daniel Borkmann and Michael S. Tsirkin for the feedback.
Yuya Kusakabe (2):
virtio_net: keep vnet header zeroed if XDP is loaded for small buffer
virtio_net: add XDP meta data support
drivers/net/virtio_net.c | 56 ++++++++++++++++++++++++----------------
1 file changed, 34 insertions(+), 22 deletions(-)
--
2.24.1
We do not want to care about the vnet header in receive_small() if XDP
is loaded, since we can not know whether or not the packet is modified
by XDP.
Fixes: f6b10209b90d ("virtio-net: switch to use build_skb() for small buffer")
Signed-off-by: Yuya Kusakabe <[email protected]>
---
drivers/net/virtio_net.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 2fe7a3188282..f39d0218bdaa 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -735,10 +735,10 @@ static struct sk_buff *receive_small(struct net_device *dev,
}
skb_reserve(skb, headroom - delta);
skb_put(skb, len);
- if (!delta) {
+ if (!xdp_prog) {
buf += header_offset;
memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
- } /* keep zeroed vnet hdr since packet was changed by bpf */
+ } /* keep zeroed vnet hdr since XDP is loaded */
err:
return skb;
--
2.24.1
Implement support for transferring XDP meta data into skb for
virtio_net driver; before calling into the program, xdp.data_meta points
to xdp.data, where on program return with pass verdict, we call
into skb_metadata_set().
Tested with the script at
https://github.com/higebu/virtio_net-xdp-metadata-test.
Signed-off-by: Yuya Kusakabe <[email protected]>
---
drivers/net/virtio_net.c | 52 ++++++++++++++++++++++++----------------
1 file changed, 32 insertions(+), 20 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f39d0218bdaa..12d115ef5e74 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -371,7 +371,7 @@ 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,
- bool hdr_valid)
+ bool hdr_valid, unsigned int metasize)
{
struct sk_buff *skb;
struct virtio_net_hdr_mrg_rxbuf *hdr;
@@ -393,6 +393,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
else
hdr_padded_len = sizeof(struct padded_vnet_hdr);
+ /* hdr_valid means no XDP, so we can copy the vnet header */
if (hdr_valid)
memcpy(hdr, p, hdr_len);
@@ -405,6 +406,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
copy = skb_tailroom(skb);
skb_put_data(skb, p, copy);
+ if (metasize) {
+ __skb_pull(skb, metasize);
+ skb_metadata_set(skb, metasize);
+ }
+
len -= copy;
offset += copy;
@@ -450,10 +456,6 @@ static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
struct virtio_net_hdr_mrg_rxbuf *hdr;
int err;
- /* virtqueue want to use data area in-front of packet */
- if (unlikely(xdpf->metasize > 0))
- return -EOPNOTSUPP;
-
if (unlikely(xdpf->headroom < vi->hdr_len))
return -EOVERFLOW;
@@ -644,6 +646,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
unsigned int delta = 0;
struct page *xdp_page;
int err;
+ unsigned int metasize = 0;
len -= vi->hdr_len;
stats->bytes += len;
@@ -683,8 +686,8 @@ static struct sk_buff *receive_small(struct net_device *dev,
xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
xdp.data = xdp.data_hard_start + xdp_headroom;
- xdp_set_data_meta_invalid(&xdp);
xdp.data_end = xdp.data + len;
+ xdp.data_meta = xdp.data;
xdp.rxq = &rq->xdp_rxq;
orig_data = xdp.data;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
@@ -695,6 +698,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
/* Recalculate length in case bpf program changed it */
delta = orig_data - xdp.data;
len = xdp.data_end - xdp.data;
+ metasize = xdp.data - xdp.data_meta;
break;
case XDP_TX:
stats->xdp_tx++;
@@ -740,6 +744,9 @@ static struct sk_buff *receive_small(struct net_device *dev,
memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
} /* keep zeroed vnet hdr since XDP is loaded */
+ if (metasize)
+ skb_metadata_set(skb, metasize);
+
err:
return skb;
@@ -760,8 +767,8 @@ static struct sk_buff *receive_big(struct net_device *dev,
struct virtnet_rq_stats *stats)
{
struct page *page = buf;
- struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len,
- PAGE_SIZE, true);
+ struct sk_buff *skb =
+ page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0);
stats->bytes += len - vi->hdr_len;
if (unlikely(!skb))
@@ -793,6 +800,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
unsigned int truesize;
unsigned int headroom = mergeable_ctx_to_headroom(ctx);
int err;
+ unsigned int metasize = 0;
head_skb = NULL;
stats->bytes += len - vi->hdr_len;
@@ -839,8 +847,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
data = page_address(xdp_page) + offset;
xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
xdp.data = data + vi->hdr_len;
- xdp_set_data_meta_invalid(&xdp);
xdp.data_end = xdp.data + (len - vi->hdr_len);
+ xdp.data_meta = xdp.data;
xdp.rxq = &rq->xdp_rxq;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
@@ -848,24 +856,27 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
switch (act) {
case XDP_PASS:
+ metasize = xdp.data - xdp.data_meta;
+
/* recalculate offset to account for any header
- * adjustments. Note other cases do not build an
- * skb and avoid using offset
+ * adjustments and minus the metasize to copy the
+ * metadata in page_to_skb(). Note other cases do not
+ * build an skb and avoid using offset
*/
- offset = xdp.data -
- page_address(xdp_page) - vi->hdr_len;
+ offset = xdp.data - page_address(xdp_page) -
+ vi->hdr_len - metasize;
- /* recalculate len if xdp.data or xdp.data_end were
- * adjusted
+ /* recalculate len if xdp.data, xdp.data_end or
+ * xdp.data_meta were adjusted
*/
- len = xdp.data_end - xdp.data + vi->hdr_len;
+ len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
/* We can only create skb based on xdp_page. */
if (unlikely(xdp_page != page)) {
rcu_read_unlock();
put_page(page);
- head_skb = page_to_skb(vi, rq, xdp_page,
- offset, len,
- PAGE_SIZE, false);
+ head_skb = page_to_skb(vi, rq, xdp_page, offset,
+ len, PAGE_SIZE, false,
+ metasize);
return head_skb;
}
break;
@@ -921,7 +932,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
goto err_skb;
}
- head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog);
+ head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
+ metasize);
curr_skb = head_skb;
if (unlikely(!curr_skb))
--
2.24.1
On 2020/2/25 上午11:32, Yuya Kusakabe wrote:
> We do not want to care about the vnet header in receive_small() if XDP
> is loaded, since we can not know whether or not the packet is modified
> by XDP.
>
> Fixes: f6b10209b90d ("virtio-net: switch to use build_skb() for small buffer")
> Signed-off-by: Yuya Kusakabe <[email protected]>
> ---
> drivers/net/virtio_net.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 2fe7a3188282..f39d0218bdaa 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -735,10 +735,10 @@ static struct sk_buff *receive_small(struct net_device *dev,
> }
> skb_reserve(skb, headroom - delta);
> skb_put(skb, len);
> - if (!delta) {
> + if (!xdp_prog) {
> buf += header_offset;
> memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
> - } /* keep zeroed vnet hdr since packet was changed by bpf */
> + } /* keep zeroed vnet hdr since XDP is loaded */
>
> err:
> return skb;
Acked-by: Jason Wang <[email protected]>
On 2020/2/25 上午11:32, Yuya Kusakabe wrote:
> Implement support for transferring XDP meta data into skb for
> virtio_net driver; before calling into the program, xdp.data_meta points
> to xdp.data, where on program return with pass verdict, we call
> into skb_metadata_set().
>
> Tested with the script at
> https://github.com/higebu/virtio_net-xdp-metadata-test.
>
> Signed-off-by: Yuya Kusakabe <[email protected]>
Acked-by: Jason Wang <[email protected]>
On Tue, Feb 25, 2020 at 12:32:11PM +0900, Yuya Kusakabe wrote:
> We do not want to care about the vnet header in receive_small() if XDP
> is loaded, since we can not know whether or not the packet is modified
> by XDP.
>
> Fixes: f6b10209b90d ("virtio-net: switch to use build_skb() for small buffer")
> Signed-off-by: Yuya Kusakabe <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
> ---
> drivers/net/virtio_net.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 2fe7a3188282..f39d0218bdaa 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -735,10 +735,10 @@ static struct sk_buff *receive_small(struct net_device *dev,
> }
> skb_reserve(skb, headroom - delta);
> skb_put(skb, len);
> - if (!delta) {
> + if (!xdp_prog) {
> buf += header_offset;
> memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
> - } /* keep zeroed vnet hdr since packet was changed by bpf */
> + } /* keep zeroed vnet hdr since XDP is loaded */
>
> err:
> return skb;
> --
> 2.24.1
On Tue, Feb 25, 2020 at 12:32:12PM +0900, Yuya Kusakabe wrote:
> Implement support for transferring XDP meta data into skb for
> virtio_net driver; before calling into the program, xdp.data_meta points
> to xdp.data, where on program return with pass verdict, we call
> into skb_metadata_set().
>
> Tested with the script at
> https://github.com/higebu/virtio_net-xdp-metadata-test.
>
> Signed-off-by: Yuya Kusakabe <[email protected]>
> ---
Acked-by: Michael S. Tsirkin <[email protected]>
> drivers/net/virtio_net.c | 52 ++++++++++++++++++++++++----------------
> 1 file changed, 32 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index f39d0218bdaa..12d115ef5e74 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -371,7 +371,7 @@ 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,
> - bool hdr_valid)
> + bool hdr_valid, unsigned int metasize)
> {
> struct sk_buff *skb;
> struct virtio_net_hdr_mrg_rxbuf *hdr;
> @@ -393,6 +393,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> else
> hdr_padded_len = sizeof(struct padded_vnet_hdr);
>
> + /* hdr_valid means no XDP, so we can copy the vnet header */
> if (hdr_valid)
> memcpy(hdr, p, hdr_len);
>
> @@ -405,6 +406,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> copy = skb_tailroom(skb);
> skb_put_data(skb, p, copy);
>
> + if (metasize) {
> + __skb_pull(skb, metasize);
> + skb_metadata_set(skb, metasize);
> + }
> +
> len -= copy;
> offset += copy;
>
> @@ -450,10 +456,6 @@ static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
> struct virtio_net_hdr_mrg_rxbuf *hdr;
> int err;
>
> - /* virtqueue want to use data area in-front of packet */
> - if (unlikely(xdpf->metasize > 0))
> - return -EOPNOTSUPP;
> -
> if (unlikely(xdpf->headroom < vi->hdr_len))
> return -EOVERFLOW;
>
> @@ -644,6 +646,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
> unsigned int delta = 0;
> struct page *xdp_page;
> int err;
> + unsigned int metasize = 0;
>
> len -= vi->hdr_len;
> stats->bytes += len;
> @@ -683,8 +686,8 @@ static struct sk_buff *receive_small(struct net_device *dev,
>
> xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
> xdp.data = xdp.data_hard_start + xdp_headroom;
> - xdp_set_data_meta_invalid(&xdp);
> xdp.data_end = xdp.data + len;
> + xdp.data_meta = xdp.data;
> xdp.rxq = &rq->xdp_rxq;
> orig_data = xdp.data;
> act = bpf_prog_run_xdp(xdp_prog, &xdp);
> @@ -695,6 +698,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
> /* Recalculate length in case bpf program changed it */
> delta = orig_data - xdp.data;
> len = xdp.data_end - xdp.data;
> + metasize = xdp.data - xdp.data_meta;
> break;
> case XDP_TX:
> stats->xdp_tx++;
> @@ -740,6 +744,9 @@ static struct sk_buff *receive_small(struct net_device *dev,
> memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
> } /* keep zeroed vnet hdr since XDP is loaded */
>
> + if (metasize)
> + skb_metadata_set(skb, metasize);
> +
> err:
> return skb;
>
> @@ -760,8 +767,8 @@ static struct sk_buff *receive_big(struct net_device *dev,
> struct virtnet_rq_stats *stats)
> {
> struct page *page = buf;
> - struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len,
> - PAGE_SIZE, true);
> + struct sk_buff *skb =
> + page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0);
>
> stats->bytes += len - vi->hdr_len;
> if (unlikely(!skb))
> @@ -793,6 +800,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> unsigned int truesize;
> unsigned int headroom = mergeable_ctx_to_headroom(ctx);
> int err;
> + unsigned int metasize = 0;
>
> head_skb = NULL;
> stats->bytes += len - vi->hdr_len;
> @@ -839,8 +847,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> data = page_address(xdp_page) + offset;
> xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
> xdp.data = data + vi->hdr_len;
> - xdp_set_data_meta_invalid(&xdp);
> xdp.data_end = xdp.data + (len - vi->hdr_len);
> + xdp.data_meta = xdp.data;
> xdp.rxq = &rq->xdp_rxq;
>
> act = bpf_prog_run_xdp(xdp_prog, &xdp);
> @@ -848,24 +856,27 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
>
> switch (act) {
> case XDP_PASS:
> + metasize = xdp.data - xdp.data_meta;
> +
> /* recalculate offset to account for any header
> - * adjustments. Note other cases do not build an
> - * skb and avoid using offset
> + * adjustments and minus the metasize to copy the
> + * metadata in page_to_skb(). Note other cases do not
> + * build an skb and avoid using offset
> */
> - offset = xdp.data -
> - page_address(xdp_page) - vi->hdr_len;
> + offset = xdp.data - page_address(xdp_page) -
> + vi->hdr_len - metasize;
>
> - /* recalculate len if xdp.data or xdp.data_end were
> - * adjusted
> + /* recalculate len if xdp.data, xdp.data_end or
> + * xdp.data_meta were adjusted
> */
> - len = xdp.data_end - xdp.data + vi->hdr_len;
> + len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
> /* We can only create skb based on xdp_page. */
> if (unlikely(xdp_page != page)) {
> rcu_read_unlock();
> put_page(page);
> - head_skb = page_to_skb(vi, rq, xdp_page,
> - offset, len,
> - PAGE_SIZE, false);
> + head_skb = page_to_skb(vi, rq, xdp_page, offset,
> + len, PAGE_SIZE, false,
> + metasize);
> return head_skb;
> }
> break;
> @@ -921,7 +932,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> goto err_skb;
> }
>
> - head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog);
> + head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
> + metasize);
> curr_skb = head_skb;
>
> if (unlikely(!curr_skb))
> --
> 2.24.1
On 2/25/20 4:31 AM, Yuya Kusakabe wrote:
> This patch series has 2 patches.
>
> Patch 1/2: keep vnet header zeroed if XDP is loaded for small buffer
> With this fix, we do not need to care about vnet header in XDP meta data
> support for small buffer, even though XDP meta data uses in front of
> packet as same as vnet header.
> It would be best if this patch goes into stable.
> This patch is based on the feedback by Jason Wang and Michael S. Tsirkin.
> https://lore.kernel.org/netdev/[email protected]/
> https://lore.kernel.org/netdev/[email protected]/
>
> Patch 2/2: add XDP meta data support
>
> Thanks to Jason Wang, Daniel Borkmann and Michael S. Tsirkin for the feedback.
>
> Yuya Kusakabe (2):
> virtio_net: keep vnet header zeroed if XDP is loaded for small buffer
> virtio_net: add XDP meta data support
>
> drivers/net/virtio_net.c | 56 ++++++++++++++++++++++++----------------
> 1 file changed, 34 insertions(+), 22 deletions(-)
>
Applied, thanks!