From nobody Mon Oct 6 22:49:02 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9978528BA9C; Thu, 17 Jul 2025 09:01:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752742891; cv=none; b=MyGgCvGQU9mhN4pt3VzoHyxT5JZAz5G2DBmkhHk3kUJuDpHwIDsQX+VR86sKQjk26a6tjShQwm/Bhoy0hweOAIctDmweZziIXZJmuiv8VqjBbz2+M/hvbURJarzeJ0SmDiz7OOJ58yaWf+5EmBspyByerGk7DtXeB1omvToc4zQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752742891; c=relaxed/simple; bh=jGY71brbCxVnS7zG6bdYK5nYqAE6JIwRi73eOnclaeI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XxPEvH8376WMF/NZNRoue32DACBs07gHz9dRSLeH0D7PMBu8V+OLnXXvQz34hKNKHLPMm1wnrseOolcf1VBGaC+WrgFdHC7fNZEV3ylMi1UV50dJk9vsD+edhduKfOxol/ry4TRS9nv/IhwboFwAVgzaWMpCEO5gpZIP8U61uO0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lrIib8TX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lrIib8TX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A541C4CEED; Thu, 17 Jul 2025 09:01:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752742891; bh=jGY71brbCxVnS7zG6bdYK5nYqAE6JIwRi73eOnclaeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lrIib8TX64gvSL8fPYeug8DY7bXH1v3evjQ/EEOwOvPPt+D7M0xLW90RwDv/4Tk9k lNi6SbrZg/Ueyib7I5B63HKu11Pz/m24tIzbR3UYhlNfbXszqrYAMuw/OOuQS6EX0r ORCFo0QblHMdLeTumF03r146fH4UKo6C7KxUVwcnvGp80Bk5x1apU/Ne5KXTF71wa3 OBawlnw/sbl72EmvoPvk07ROAThBhuRPmMlckZFuMmza+vSJYaPWcelz9JQsUI3ikD go7JUkxvKtOFCY5xXb/FGrFlqSEJQ7zJy2WMHCB4JoyPkVlX3A/O+IE1C7GgvP2zS6 6eR62UTY2MMjw== From: Will Deacon To: linux-kernel@vger.kernel.org Cc: Will Deacon , Keir Fraser , Steven Moreland , Frederick Mayle , Stefan Hajnoczi , Stefano Garzarella , "Michael S. Tsirkin" , Jason Wang , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , netdev@vger.kernel.org, virtualization@lists.linux.dev Subject: [PATCH v4 3/9] vsock/virtio: Move length check to callers of virtio_vsock_skb_rx_put() Date: Thu, 17 Jul 2025 10:01:10 +0100 Message-Id: <20250717090116.11987-4-will@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250717090116.11987-1-will@kernel.org> References: <20250717090116.11987-1-will@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" virtio_vsock_skb_rx_put() only calls skb_put() if the length in the packet header is not zero even though skb_put() handles this case gracefully. Remove the functionally redundant check from virtio_vsock_skb_rx_put() and, on the assumption that this is a worthwhile optimisation for handling credit messages, augment the existing length checks in virtio_transport_rx_work() to elide the call for zero-length payloads. Since the callers all have the length, extend virtio_vsock_skb_rx_put() to take it as an additional parameter rather than fish it back out of the packet header. Note that the vhost code already has similar logic in vhost_vsock_alloc_skb(). Reviewed-by: Stefano Garzarella Signed-off-by: Will Deacon --- drivers/vhost/vsock.c | 2 +- include/linux/virtio_vsock.h | 9 ++------- net/vmw_vsock/virtio_transport.c | 4 +++- 3 files changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 66a0f060770e..4c4a642945eb 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -375,7 +375,7 @@ vhost_vsock_alloc_skb(struct vhost_virtqueue *vq, return NULL; } =20 - virtio_vsock_skb_rx_put(skb); + virtio_vsock_skb_rx_put(skb, payload_len); =20 nbytes =3D copy_from_iter(skb->data, payload_len, &iov_iter); if (nbytes !=3D payload_len) { diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index 36fb3edfa403..97465f378ade 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -47,14 +47,9 @@ static inline void virtio_vsock_skb_clear_tap_delivered(= struct sk_buff *skb) VIRTIO_VSOCK_SKB_CB(skb)->tap_delivered =3D false; } =20 -static inline void virtio_vsock_skb_rx_put(struct sk_buff *skb) +static inline void virtio_vsock_skb_rx_put(struct sk_buff *skb, u32 len) { - u32 len; - - len =3D le32_to_cpu(virtio_vsock_hdr(skb)->len); - - if (len > 0) - skb_put(skb, len); + skb_put(skb, len); } =20 static inline struct sk_buff *virtio_vsock_alloc_skb(unsigned int size, gf= p_t mask) diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transp= ort.c index eb08a393413d..0166919f8705 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -656,7 +656,9 @@ static void virtio_transport_rx_work(struct work_struct= *work) continue; } =20 - virtio_vsock_skb_rx_put(skb); + if (payload_len) + virtio_vsock_skb_rx_put(skb, payload_len); + virtio_transport_deliver_tap_pkt(skb); virtio_transport_recv_pkt(&virtio_transport, skb); } --=20 2.50.0.727.gbf7dc18ff4-goog