From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=MK/29ETM; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by passt.top (Postfix) with ESMTPS id 567BD5A0262 for ; Wed, 01 Apr 2026 21:18:41 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1775071120; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WWs7eReD6wKuqNCZfib4B0lw1rELyB6FQ6JjRZ5H9JQ=; b=MK/29ETM7WVJZsKbC5chlR5YVpkxW5okT0C30xmFJBDtfY2sQ4nHUOleUXNcZEpDAKCDZ4 /ae159QshCTSLENpOiVsUV4L4F2qIPMh41zjTI01IGGXt0IDVbhRUHiap+3ut6BJXnItAn ze+eowfk12swmISBmAJ4ObbSQsCKF6M= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-249-K4GBlscJPYSVDa-3r-Vh0g-1; Wed, 01 Apr 2026 15:18:38 -0400 X-MC-Unique: K4GBlscJPYSVDa-3r-Vh0g-1 X-Mimecast-MFC-AGG-ID: K4GBlscJPYSVDa-3r-Vh0g_1775071118 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2E61D180034F for ; Wed, 1 Apr 2026 19:18:38 +0000 (UTC) Received: from lenovo-t14s.redhat.corp (headnet01.pony-001.prod.iad2.dc.redhat.com [10.2.32.101]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 4DF4F19560AB; Wed, 1 Apr 2026 19:18:37 +0000 (UTC) From: Laurent Vivier To: passt-dev@passt.top Subject: [PATCH 08/10] vu_common: Pass explicit frame length to vu_flush() Date: Wed, 1 Apr 2026 21:18:24 +0200 Message-ID: <20260401191826.1782394-9-lvivier@redhat.com> In-Reply-To: <20260401191826.1782394-1-lvivier@redhat.com> References: <20260401191826.1782394-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: YZbqJm7NVpxhIUdnLZgTRE6AARbJOgbxX0E-WreG3jw_1775071118 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: 5LBUUTCI3KCHTHNYUXVBWUWWN7NL5A3R X-Message-ID-Hash: 5LBUUTCI3KCHTHNYUXVBWUWWN7NL5A3R X-MailFrom: lvivier@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Laurent Vivier X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Currently vu_flush() derives the frame size from the iov, but in preparation for iov arrays that may be larger than the actual frame, pass the total length (including vnet header) explicitly so that only the relevant portion is reported to the virtqueue. Ensure a minimum frame size of ETH_ZLEN + VNET_HLEN to handle short frames. All elements are still flushed to avoid descriptor leaks, but trailing elements beyond frame_len will report a zero length. Signed-off-by: Laurent Vivier --- tcp_vu.c | 6 +++--- udp_vu.c | 2 +- vu_common.c | 15 ++++++++++++--- vu_common.h | 2 +- 4 files changed, 17 insertions(+), 8 deletions(-) diff --git a/tcp_vu.c b/tcp_vu.c index 329fa969fca1..105bca41c6de 100644 --- a/tcp_vu.c +++ b/tcp_vu.c @@ -140,7 +140,7 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) l2len = optlen + hdrlen - VNET_HLEN; vu_pad(&flags_elem[0].in_sg[0], l2len); - vu_flush(vdev, vq, flags_elem, 1); + vu_flush(vdev, vq, flags_elem, 1, hdrlen + optlen); if (*c->pcap) pcap_iov(&flags_elem[0].in_sg[0], 1, VNET_HLEN, @@ -157,7 +157,7 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) flags_elem[0].in_sg[0].iov_base, flags_elem[0].in_sg[0].iov_len); - vu_flush(vdev, vq, &flags_elem[1], 1); + vu_flush(vdev, vq, &flags_elem[1], 1, hdrlen + optlen); if (*c->pcap) pcap_iov(&flags_elem[1].in_sg[0], 1, VNET_HLEN, @@ -463,7 +463,7 @@ int tcp_vu_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn) l2len = dlen + hdrlen - VNET_HLEN; vu_pad(iov, l2len); - vu_flush(vdev, vq, &elem[head[i]], buf_cnt); + vu_flush(vdev, vq, &elem[head[i]], buf_cnt, dlen + hdrlen); if (*c->pcap) pcap_iov(iov, buf_cnt, VNET_HLEN, diff --git a/udp_vu.c b/udp_vu.c index 81491afa7e6a..4641f42eb5c4 100644 --- a/udp_vu.c +++ b/udp_vu.c @@ -234,7 +234,7 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx) pcap_iov(iov_vu, iov_cnt, VNET_HLEN, hdrlen + dlen - VNET_HLEN); } - vu_flush(vdev, vq, elem, elem_used); + vu_flush(vdev, vq, elem, elem_used, hdrlen + dlen); vu_queue_notify(vdev, vq); } } diff --git a/vu_common.c b/vu_common.c index f254cb67ec78..d371a59a1813 100644 --- a/vu_common.c +++ b/vu_common.c @@ -134,18 +134,27 @@ static void vu_set_vnethdr(struct virtio_net_hdr_mrg_rxbuf *vnethdr, * @vq: vhost-user virtqueue * @elem: virtqueue elements array to send back to the virtqueue * @elem_cnt: Length of the array + * @frame_len: Total frame length including vnet header */ void vu_flush(const struct vu_dev *vdev, struct vu_virtq *vq, - struct vu_virtq_element *elem, int elem_cnt) + struct vu_virtq_element *elem, int elem_cnt, size_t frame_len) { + size_t len; int i; vu_set_vnethdr(elem[0].in_sg[0].iov_base, elem_cnt); + len = MAX(ETH_ZLEN + VNET_HLEN, frame_len); for (i = 0; i < elem_cnt; i++) { - size_t elem_size = iov_size(elem[i].in_sg, elem[i].in_num); + size_t elem_size; + + elem_size = iov_size(elem[i].in_sg, elem[i].in_num); + if (elem_size > len) + elem_size = len; vu_queue_fill(vdev, vq, &elem[i], elem_size, i); + + len -= elem_size; } vu_queue_flush(vdev, vq, elem_cnt); @@ -270,7 +279,7 @@ int vu_send_single(const struct ctx *c, const void *buf, size_t size) if (*c->pcap) pcap_iov(in_sg, in_total, VNET_HLEN, size); - vu_flush(vdev, vq, elem, elem_cnt); + vu_flush(vdev, vq, elem, elem_cnt, VNET_HLEN + size); vu_queue_notify(vdev, vq); trace("vhost-user sent %zu", total); diff --git a/vu_common.h b/vu_common.h index 4037ab765b7d..77d1849e6115 100644 --- a/vu_common.h +++ b/vu_common.h @@ -40,7 +40,7 @@ int vu_collect(const struct vu_dev *vdev, struct vu_virtq *vq, struct iovec *in_sg, size_t max_in_sg, size_t *in_total, size_t size, size_t *collected); void vu_flush(const struct vu_dev *vdev, struct vu_virtq *vq, - struct vu_virtq_element *elem, int elem_cnt); + struct vu_virtq_element *elem, int elem_cnt, size_t frame_len); void vu_kick_cb(struct vu_dev *vdev, union epoll_ref ref, const struct timespec *now); int vu_send_single(const struct ctx *c, const void *buf, size_t size); -- 2.53.0