From mboxrd@z Thu Jan 1 00:00:00 1970 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 A85CB1EA80; Wed, 2 Oct 2024 14:43:16 +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=1727880196; cv=none; b=Rk1FCSZE2adyjVMYco8fWwBIJ2hWlX0mrCshKeaQd+LT0R4S5VT38jeCyizjWSo7fzf7xtYNRMcDCXb5aDvOF5S4HIQqrrKGNuUPdHyI0q+jvRln0bz72HRBtMh91u2vngkL4CFam1B1/DYxgRlJnyN+kjCvOJ1n1SKzxMsyi7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727880196; c=relaxed/simple; bh=mqWCILg/ruJipzg0dKu38lx3DrhAgJcR9g1r5xc5XSs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Dd3MT++rkyCda8lgbpaj6E0k5zbEPlR0m0rUq0DcXUMwOqZmxTy3qayE3yD25HdWOcR7gpfM9UttEHiXa5fg88AWTCpdH2xRtdazVBM/hGphv5AJYklKIDfEoTo/aDorvsrvc+Si5kVPE1ePqWHHGBICSySM8RVFTTP0GzvYCWw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ebJcnwpQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ebJcnwpQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDD05C4CEC2; Wed, 2 Oct 2024 14:43:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727880196; bh=mqWCILg/ruJipzg0dKu38lx3DrhAgJcR9g1r5xc5XSs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ebJcnwpQ/QvMQwyb7FeJQG3qhKWlVifoxk0XrGH3ip9XFMNsvGyEOumr5BrtayUfa /+Fu8x5+DXuFAIc8ZXu3cocU4lI4lCkE1pBfLEBJYYBDiR8rXVVcyFiMLBaeRR2JHS kXpdwe2mVUsvpbe/DTVNF/awPx/cr0YyaSJMbsdw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Wenbo Li , Jiahui Cen , Ying Fang , Xuan Zhuo , Paolo Abeni , Sasha Levin Subject: [PATCH 6.6 377/538] virtio_net: Fix mismatched buf address when unmapping for small packets Date: Wed, 2 Oct 2024 15:00:16 +0200 Message-ID: <20241002125807.312193216@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241002125751.964700919@linuxfoundation.org> References: <20241002125751.964700919@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wenbo Li [ Upstream commit c11a49d58ad229a1be1ebe08a2b68fedf83db6c8 ] Currently, the virtio-net driver will perform a pre-dma-mapping for small or mergeable RX buffer. But for small packets, a mismatched address without VIRTNET_RX_PAD and xdp_headroom is used for unmapping. That will result in unsynchronized buffers when SWIOTLB is enabled, for example, when running as a TDX guest. This patch unifies the address passed to the virtio core as the address of the virtnet header and fixes the mismatched buffer address. Changes from v2: unify the buf that passed to the virtio core in small and merge mode. Changes from v1: Use ctx to get xdp_headroom. Fixes: 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers") Signed-off-by: Wenbo Li Signed-off-by: Jiahui Cen Signed-off-by: Ying Fang Reviewed-by: Xuan Zhuo Link: https://patch.msgid.link/20240919081351.51772-1-liwenbo.martin@bytedance.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/virtio_net.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index bc01f2dafa948..2da3be3fb9423 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1269,6 +1269,11 @@ static struct sk_buff *receive_small(struct net_device *dev, struct page *page = virt_to_head_page(buf); struct sk_buff *skb; + /* We passed the address of virtnet header to virtio-core, + * so truncate the padding. + */ + buf -= VIRTNET_RX_PAD + xdp_headroom; + len -= vi->hdr_len; u64_stats_add(&stats->bytes, len); @@ -1859,8 +1864,9 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, if (unlikely(!buf)) return -ENOMEM; - virtnet_rq_init_one_sg(rq, buf + VIRTNET_RX_PAD + xdp_headroom, - vi->hdr_len + GOOD_PACKET_LEN); + buf += VIRTNET_RX_PAD + xdp_headroom; + + virtnet_rq_init_one_sg(rq, buf, vi->hdr_len + GOOD_PACKET_LEN); err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); if (err < 0) { -- 2.43.0