From: patchwork-bot+netdevbpf@kernel.org
To: Michael S. Tsirkin <mst@redhat.com>
Cc: linux-kernel@vger.kernel.org, oelghoul@linux.ibm.com,
sraithal@amd.com, jasowang@redhat.com,
xuanzhuo@linux.alibaba.com, eperezma@redhat.com,
andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, ast@kernel.org,
daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com,
sdf@fomichev.me, vishs@meta.com, netdev@vger.kernel.org,
virtualization@lists.linux.dev, bpf@vger.kernel.org
Subject: Re: [PATCH net-next] virtio_net: sync RX buffer before reading the header
Date: Fri, 27 Mar 2026 03:20:14 +0000 [thread overview]
Message-ID: <177458161428.3283168.99448398733931105.git-patchwork-notify@kernel.org> (raw)
In-Reply-To: <f4caa9be9e5addae7851c012cab0a733be7f0974.1774365273.git.mst@redhat.com>
Hello:
This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:
On Tue, 24 Mar 2026 11:15:54 -0400 you wrote:
> receive_buf() reads the virtio header through buf before
> page_pool_dma_sync_for_cpu() runs in receive_small() or
> receive_mergeable(). The header buffer is thus unsynchronized at the
> point where flags and, for mergeable buffers, num_buffers are consumed.
>
> Omar Elghoul reported that on s390x Secure Execution this showed up as
> greatly reduced virtio-net performance together with "bad gso" and
> "bad csum" messages in dmesg. This is because with SE sync actually
> copies data, so the header is uninitialized.
>
> [...]
Here is the summary with links:
- [net-next] virtio_net: sync RX buffer before reading the header
https://git.kernel.org/netdev/net-next/c/fe3e54253f0b
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
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prev parent reply other threads:[~2026-03-27 3:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-24 15:15 [PATCH net-next] virtio_net: sync RX buffer before reading the header Michael S. Tsirkin
2026-03-25 13:20 ` Vishwanath Seshagiri
2026-03-26 2:09 ` Jason Wang
2026-03-26 18:17 ` Simon Horman
2026-03-26 22:03 ` Michael S. Tsirkin
2026-03-27 3:07 ` Jakub Kicinski
2026-03-27 3:20 ` patchwork-bot+netdevbpf [this message]
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