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GET /api/patches/2194227/?format=api
{ "id": 2194227, "url": "http://patchwork.ozlabs.org/api/patches/2194227/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260207134728.1495932-10-lulu@redhat.com/", "project": { "id": 14, "url": "http://patchwork.ozlabs.org/api/projects/14/?format=api", "name": "QEMU Development", "link_name": "qemu-devel", "list_id": "qemu-devel.nongnu.org", "list_email": "qemu-devel@nongnu.org", "web_url": "", "scm_url": "", "webscm_url": "", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260207134728.1495932-10-lulu@redhat.com>", "list_archive_url": null, "date": "2026-02-07T13:47:26", "name": "[10/12] net/filter-buffer: store raw frames and synthesize vnet_hdr on release", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "3469c4c1a3e873087175801ff814e046ad436c4d", "submitter": { "id": 78960, "url": "http://patchwork.ozlabs.org/api/people/78960/?format=api", "name": "Cindy Lu", "email": "lulu@redhat.com" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260207134728.1495932-10-lulu@redhat.com/mbox/", "series": [ { "id": 491379, "url": "http://patchwork.ozlabs.org/api/series/491379/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=491379", "date": "2026-02-07T13:47:17", "name": "[01/12] net: introduce read_poll/write_poll", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/491379/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2194227/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2194227/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>", "X-Original-To": "incoming@patchwork.ozlabs.org", "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=Qr9pN24i;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)" ], "Received": [ "from lists.gnu.org (lists.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4f7XPr31Hlz1xvp\n\tfor <incoming@patchwork.ozlabs.org>; Sun, 08 Feb 2026 00:49:36 +1100 (AEDT)", "from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from <qemu-devel-bounces@nongnu.org>)\n\tid 1voigm-0004Ex-0i; Sat, 07 Feb 2026 08:49:32 -0500", "from eggs.gnu.org ([2001:470:142:3::10])\n by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <lulu@redhat.com>) id 1voigV-0003qB-MM\n for qemu-devel@nongnu.org; Sat, 07 Feb 2026 08:49:21 -0500", "from us-smtp-delivery-124.mimecast.com ([170.10.129.124])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <lulu@redhat.com>) id 1voigS-0003I7-CM\n for qemu-devel@nongnu.org; Sat, 07 Feb 2026 08:49:14 -0500", "from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com\n (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by\n relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n cipher=TLS_AES_256_GCM_SHA384) id us-mta-133-It29qq1DN86JT-m3fqzkkw-1; Sat,\n 07 Feb 2026 08:49:08 -0500", "from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com\n (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest\n SHA256)\n (No client certificate requested)\n by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS\n id 9B19F180047F; Sat, 7 Feb 2026 13:49:07 +0000 (UTC)", "from S2.redhat.com (unknown [10.72.112.15])\n by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP\n id 5C50518004BB; Sat, 7 Feb 2026 13:49:03 +0000 (UTC)" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n s=mimecast20190719; t=1770472151;\n h=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n to:to:cc:mime-version:mime-version:\n content-transfer-encoding:content-transfer-encoding:\n in-reply-to:in-reply-to:references:references;\n bh=C93QEt4+9NSIa7tGhk2Jhi8x7JbqFTf/e7c2vwZ6I7o=;\n b=Qr9pN24iI9YbdpsMyG1YmgsUG1jj7P/Yt2oFueiIGoMzwcT+BWDK3eUaJ7JmZ5GPs8N1+Y\n I1Z/x+Igv4uK8qtiW2KTJA+kPWcQ6GA0Mjt8+5LHM3b9er4rVeqlTn7lTJrxLTSXIS2hLe\n tmefiPJ0EN+4qjCQ5UTcwVRWpyhQwpc=", "X-MC-Unique": "It29qq1DN86JT-m3fqzkkw-1", "X-Mimecast-MFC-AGG-ID": "It29qq1DN86JT-m3fqzkkw_1770472147", "From": "Cindy Lu <lulu@redhat.com>", "To": "lulu@redhat.com, mst@redhat.com, jasowang@redhat.com, zhangckid@gmail.com,\n lizhijian@fujitsu.com, qemu-devel@nongnu.org", "Subject": "[PATCH 10/12] net/filter-buffer: store raw frames and synthesize\n vnet_hdr on release", "Date": "Sat, 7 Feb 2026 21:47:26 +0800", "Message-ID": "<20260207134728.1495932-10-lulu@redhat.com>", "In-Reply-To": "<20260207134728.1495932-1-lulu@redhat.com>", "References": "<20260207134728.1495932-1-lulu@redhat.com>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-Scanned-By": "MIMEDefang 3.4.1 on 10.30.177.93", "Received-SPF": "pass client-ip=170.10.129.124; envelope-from=lulu@redhat.com;\n helo=us-smtp-delivery-124.mimecast.com", "X-Spam_score_int": "-20", "X-Spam_score": "-2.1", "X-Spam_bar": "--", "X-Spam_report": "(-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001,\n RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001,\n SPF_PASS=-0.001 autolearn=ham autolearn_force=no", "X-Spam_action": "no action", "X-BeenThere": "qemu-devel@nongnu.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "qemu development <qemu-devel.nongnu.org>", "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>", "List-Archive": "<https://lists.nongnu.org/archive/html/qemu-devel>", "List-Post": "<mailto:qemu-devel@nongnu.org>", "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>", "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=subscribe>", "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org", "Sender": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org" }, "content": "Buffer only the Ethernet frame so packets can be re-framed using the current\nnetdev vnet_hdr_len at release time (important across migration). Add a custom\nqueue deliver callback to prepend a zeroed vnet_hdr when needed, and fix iov\ntrimming to avoid freeing adjusted pointers or enqueueing empty packets.\n\nSigned-off-by: Cindy Lu <lulu@redhat.com>\n---\n net/filter-buffer.c | 82 ++++++++++++++++++++++++++++++++++++++++++---\n 1 file changed, 78 insertions(+), 4 deletions(-)", "diff": "diff --git a/net/filter-buffer.c b/net/filter-buffer.c\nindex 427da24097..f26b212b06 100644\n--- a/net/filter-buffer.c\n+++ b/net/filter-buffer.c\n@@ -8,6 +8,7 @@\n \n #include \"qemu/osdep.h\"\n #include \"net/filter.h\"\n+#include \"net/net.h\"\n #include \"net/queue.h\"\n #include \"qapi/error.h\"\n #include \"qemu/timer.h\"\n@@ -28,6 +29,43 @@ struct FilterBufferState {\n QEMUTimer release_timer;\n };\n \n+static ssize_t filter_buffer_pass_to_next(NetClientState *sender,\n+ unsigned flags,\n+ const struct iovec *iov,\n+ int iovcnt,\n+ void *opaque)\n+{\n+ NetFilterState *nf = opaque;\n+ int vnet_hdr_len = 0;\n+\n+ /*\n+ * filter-buffer stores Ethernet frames without the vnet_hdr prefix.\n+ * When releasing packets, synthesize a zeroed vnet_hdr of the current\n+ * netdev vnet_hdr_len (if any) so the downstream NIC/backend sees the\n+ * expected framing even across migration where vnet_hdr_len can change.\n+ */\n+ if (nf && nf->netdev) {\n+ vnet_hdr_len = qemu_get_vnet_hdr_len(nf->netdev);\n+ }\n+\n+ if (vnet_hdr_len > 0) {\n+ uint8_t vnet_hdr[128] = { 0 };\n+ g_autofree struct iovec *iov2 = g_new(struct iovec, iovcnt + 1);\n+\n+ g_assert((size_t)vnet_hdr_len <= sizeof(vnet_hdr));\n+ iov2[0].iov_base = vnet_hdr;\n+ iov2[0].iov_len = vnet_hdr_len;\n+ memcpy(&iov2[1], iov, iovcnt * sizeof(*iov));\n+\n+ return qemu_netfilter_pass_to_next(sender,\n+ QEMU_NET_PACKET_FLAG_NONE,\n+ iov2, iovcnt + 1, opaque);\n+ }\n+\n+ return qemu_netfilter_pass_to_next(sender, QEMU_NET_PACKET_FLAG_RAW,\n+ iov, iovcnt, opaque);\n+}\n+\n static void filter_buffer_flush(NetFilterState *nf)\n {\n FilterBufferState *s = FILTER_BUFFER(nf);\n@@ -64,6 +102,11 @@ static ssize_t filter_buffer_receive_iov(NetFilterState *nf,\n NetPacketSent *sent_cb)\n {\n FilterBufferState *s = FILTER_BUFFER(nf);\n+ size_t skip = 0;\n+ size_t total;\n+ struct iovec *iov_copy;\n+ struct iovec *iov_copy_base;\n+ unsigned int iovcnt_copy;\n \n /*\n * We return size when buffer a packet, the sender will take it as\n@@ -79,9 +122,40 @@ static ssize_t filter_buffer_receive_iov(NetFilterState *nf,\n * the packets without caring about the receiver. This is suboptimal.\n * May need more thoughts (e.g keeping sent_cb).\n */\n- qemu_net_queue_append_iov(s->incoming_queue, sender, flags,\n- iov, iovcnt, NULL);\n- return iov_size(iov, iovcnt);\n+ total = iov_size(iov, iovcnt);\n+\n+ /*\n+ * The backend (e.g. tap) may prepend a vnet_hdr. Buffer only the Ethernet\n+ * frame so we can re-synthesize the right vnet_hdr_len at release time.\n+ */\n+ if (!(flags & QEMU_NET_PACKET_FLAG_RAW) && nf->netdev) {\n+ skip = qemu_get_vnet_hdr_len(nf->netdev);\n+ if (skip > total) {\n+ skip = total;\n+ }\n+ }\n+\n+ iov_copy = g_new(struct iovec, iovcnt);\n+ iov_copy_base = iov_copy;\n+ memcpy(iov_copy, iov, iovcnt * sizeof(*iov_copy));\n+ iovcnt_copy = iovcnt;\n+ if (skip) {\n+ iov_discard_front(&iov_copy, &iovcnt_copy, skip);\n+ }\n+ if (iovcnt_copy == 0) {\n+ g_free(iov_copy_base);\n+ return total;\n+ }\n+\n+ /*\n+ * Stored packets are raw Ethernet frames (no vnet_hdr prefix).\n+ */\n+ qemu_net_queue_append_iov(s->incoming_queue, sender,\n+ QEMU_NET_PACKET_FLAG_RAW,\n+ iov_copy, iovcnt_copy, NULL);\n+ g_free(iov_copy_base);\n+\n+ return total;\n }\n \n static void filter_buffer_cleanup(NetFilterState *nf)\n@@ -126,7 +200,7 @@ static void filter_buffer_setup(NetFilterState *nf, Error **errp)\n return;\n }\n \n- s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);\n+ s->incoming_queue = qemu_new_net_queue(filter_buffer_pass_to_next, nf);\n filter_buffer_setup_timer(nf);\n }\n \n", "prefixes": [ "10/12" ] }