diff mbox series

[Stable-8.2.3,73/87] hw/net/net_tx_pkt: Fix virtio header without checksum offloading

Message ID 20240410072303.4191455-73-mjt@tls.msk.ru
State New
Headers show
Series Patch Round-up for stable 8.2.3, freeze on 2024-04-20 | expand

Commit Message

Michael Tokarev April 10, 2024, 7:22 a.m. UTC 
From: Akihiko Odaki <akihiko.odaki@daynix.com>

It is incorrect to have the VIRTIO_NET_HDR_F_NEEDS_CSUM set when
checksum offloading is disabled so clear the bit.

TCP/UDP checksum is usually offloaded when the peer requires virtio
headers because they can instruct the peer to compute checksum. However,
igb disables TX checksum offloading when a VF is enabled whether the
peer requires virtio headers because a transmitted packet can be routed
to it and it expects the packet has a proper checksum. Therefore, it
is necessary to have a correct virtio header even when checksum
offloading is disabled.

A real TCP/UDP checksum will be computed and saved in the buffer when
checksum offloading is disabled. The virtio specification requires to
set the packet checksum stored in the buffer to the TCP/UDP pseudo
header when the VIRTIO_NET_HDR_F_NEEDS_CSUM bit is set so the bit must
be cleared in that case.

Fixes: ffbd2dbd8e64 ("e1000e: Perform software segmentation for loopback")
Buglink: https://issues.redhat.com/browse/RHEL-23067
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit 89a8de364b51db8107d2a210314431885ac52238)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff mbox series

Patch

diff --git a/hw/net/net_tx_pkt.c b/hw/net/net_tx_pkt.c
index 2e5f58b3c9..2134a18c4c 100644
--- a/hw/net/net_tx_pkt.c
+++ b/hw/net/net_tx_pkt.c
@@ -833,6 +833,7 @@  bool net_tx_pkt_send_custom(struct NetTxPkt *pkt, bool offload,
 
     if (offload || gso_type == VIRTIO_NET_HDR_GSO_NONE) {
         if (!offload && pkt->virt_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
+            pkt->virt_hdr.flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
             net_tx_pkt_do_sw_csum(pkt, &pkt->vec[NET_TX_PKT_L2HDR_FRAG],
                                   pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1,
                                   pkt->payload_len);