Michael S. Tsirkin
2021-Aug-02 16:58 UTC
[PATCH net v2 0/2] virtio-net: fix for build_skb()
On Fri, Jul 30, 2021 at 05:16:43AM -0700, Jakub Kicinski wrote:> On Tue, 1 Jun 2021 07:06:43 -0400 Michael S. Tsirkin wrote: > > On Tue, Jun 01, 2021 at 02:39:58PM +0800, Xuan Zhuo wrote: > > > #1 Fixed a serious error. > > > #2 Fixed a logical error, but this error did not cause any serious consequences. > > > > > > The logic of this piece is really messy. Fortunately, my refactored patch can be > > > completed with a small amount of testing. > > > > Looks good, thanks! > > Also needed for stable I think. > > > > Acked-by: Michael S. Tsirkin <mst at redhat.com> > > Just a heads up folks, looks like we ended up merging both this and the > net-next version of the patch set: > > 8fb7da9e9907 virtio_net: get build_skb() buf by data ptr > 5c37711d9f27 virtio-net: fix for unable to handle page fault for address > > and > > 7bf64460e3b2 virtio-net: get build_skb() buf by data ptr > 6c66c147b9a4 virtio-net: fix for unable to handle page fault for address > > Are you okay with the code as is or should we commit something like:Yes: Acked-by: Michael S. Tsirkin <mst at redhat.com> Will you post this one then?> --- > > 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))