diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2025-10-31 09:05:51 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-11-05 04:14:07 +0300 |
| commit | c3838262b824c71c145cd3668722e99a69bc9cd9 (patch) | |
| tree | 5ac686699c9fe70fd2eb7d2467f86f02376b34e4 /include | |
| parent | e120f46768d98151ece8756ebd688b0e43dc8b29 (diff) | |
| download | linux-c3838262b824c71c145cd3668722e99a69bc9cd9.tar.xz | |
virtio_net: fix alignment for virtio_net_hdr_v1_hash
Changing alignment of header would mean it's no longer safe to cast a
2 byte aligned pointer between formats. Use two 16 bit fields to make
it 2 byte aligned as previously.
This fixes the performance regression since
commit ("virtio_net: enable gso over UDP tunnel support.") as it uses
virtio_net_hdr_v1_hash_tunnel which embeds
virtio_net_hdr_v1_hash. Pktgen in guest + XDP_DROP on TAP + vhost_net
shows the TX PPS is recovered from 2.4Mpps to 4.45Mpps.
Fixes: 56a06bd40fab ("virtio_net: enable gso over UDP tunnel support.")
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Link: https://patch.msgid.link/20251031060551.126-1-jasowang@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/virtio_net.h | 3 | ||||
| -rw-r--r-- | include/uapi/linux/virtio_net.h | 3 |
2 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 4d1780848d0e..b673c31569f3 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -401,7 +401,8 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, if (!tnl_hdr_negotiated) return -EINVAL; - vhdr->hash_hdr.hash_value = 0; + vhdr->hash_hdr.hash_value_lo = 0; + vhdr->hash_hdr.hash_value_hi = 0; vhdr->hash_hdr.hash_report = 0; vhdr->hash_hdr.padding = 0; diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h index 8bf27ab8bcb4..1db45b01532b 100644 --- a/include/uapi/linux/virtio_net.h +++ b/include/uapi/linux/virtio_net.h @@ -193,7 +193,8 @@ struct virtio_net_hdr_v1 { struct virtio_net_hdr_v1_hash { struct virtio_net_hdr_v1 hdr; - __le32 hash_value; + __le16 hash_value_lo; + __le16 hash_value_hi; #define VIRTIO_NET_HASH_REPORT_NONE 0 #define VIRTIO_NET_HASH_REPORT_IPv4 1 #define VIRTIO_NET_HASH_REPORT_TCPv4 2 |