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([2a0d:3344:2712:7e10:4d59:d956:544f:d65c]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-429952df62dsm27290030f8f.45.2025.10.29.01.18.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 29 Oct 2025 01:18:47 -0700 (PDT) Message-ID: <96f6d774-457e-4bdf-a0b1-eb6f64b99a46@redhat.com> Date: Wed, 29 Oct 2025 09:18:46 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net] virtio-net: calculate header alignment mask based on features To: "Michael S. Tsirkin" , Jason Wang Cc: xuanzhuo@linux.alibaba.com, eperezma@redhat.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, virtualization@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20251028030341.46023-1-jasowang@redhat.com> <20251028101144-mutt-send-email-mst@kernel.org> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20251028101144-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/28/25 3:38 PM, Michael S. Tsirkin wrote: > So how about just fixing the root cause then? > Like this (untested, if you agree pls take over this): > > --- > > 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. > > Signed-off-by: Michael S. Tsirkin FWIW, I like this solution. With the u16/u32 change, feel free to add: Acked-by: Paolo Abeni