Re: [PATCH net-next] virtio-net: realign page_to_skb() after merges
From: Jason Wang <hidden>
Date: 2021-08-03 02:51:31
Also in:
virtualization
在 2021/8/3 上午1:57, Jakub Kicinski 写道:
We ended up merging two versions of the same patch set:
commit 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr")
commit 5c37711d9f27 ("virtio-net: fix for unable to handle page fault for address")
into net, and
commit 7bf64460e3b2 ("virtio-net: get build_skb() buf by data ptr")
commit 6c66c147b9a4 ("virtio-net: fix for unable to handle page fault for address")
into net-next. Redo the merge from commit 126285651b7f ("Merge
ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net"), so that
the most recent code remains.
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>Acked-by: Jason Wang <redacted>
quoted hunk ↗ jump to hunk
--- drivers/net/virtio_net.c | 27 ++++++++------------------- 1 file changed, 8 insertions(+), 19 deletions(-)diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 56c3f8519093..74482a52f076 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c@@ -380,7 +380,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, struct page *page, unsigned int offset, unsigned int len, unsigned int truesize, bool hdr_valid, unsigned int metasize, - bool whole_page) + unsigned int headroom) { struct sk_buff *skb; struct virtio_net_hdr_mrg_rxbuf *hdr;@@ -398,28 +398,16 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, else hdr_padded_len = sizeof(struct padded_vnet_hdr); - /* If whole_page, there is an offset between the beginning of the + /* If headroom is not 0, there is an offset between the beginning of the * data and the allocated space, otherwise the data and the allocated * space are aligned. * * Buffers with headroom use PAGE_SIZE as alloc size, see * add_recvbuf_mergeable() + get_mergeable_buf_len() */ - if (whole_page) { - /* Buffers with whole_page use PAGE_SIZE as alloc size, - * see add_recvbuf_mergeable() + get_mergeable_buf_len() - */ - truesize = PAGE_SIZE; - - /* page maybe head page, so we should get the buf by p, not the - * page - */ - tailroom = truesize - len - offset_in_page(p); - buf = (char *)((unsigned long)p & PAGE_MASK); - } else { - tailroom = truesize - len; - buf = p; - } + truesize = headroom ? PAGE_SIZE : truesize; + tailroom = truesize - len - headroom; + buf = p - headroom; len -= hdr_len; offset += hdr_padded_len;@@ -978,7 +966,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, put_page(page); head_skb = page_to_skb(vi, rq, xdp_page, offset, len, PAGE_SIZE, false, - metasize, true); + metasize, + VIRTIO_XDP_HEADROOM); return head_skb; } break;@@ -1029,7 +1018,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, rcu_read_unlock(); head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog, - metasize, !!headroom); + metasize, headroom); curr_skb = head_skb; if (unlikely(!curr_skb))