From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=51041 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OLYcW-0006BF-Jf for qemu-devel@nongnu.org; Mon, 07 Jun 2010 05:28:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OLYc1-0001s0-53 for qemu-devel@nongnu.org; Mon, 07 Jun 2010 05:27:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29696) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OLYc0-0001rm-QS for qemu-devel@nongnu.org; Mon, 07 Jun 2010 05:27:17 -0400 Received: from int-mx08.intmail.prod.int.phx2.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o579RFX2014372 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 7 Jun 2010 05:27:15 -0400 Received: from redhat.com (vpn-6-161.tlv.redhat.com [10.35.6.161]) by int-mx08.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with SMTP id o579RDkL021266 for ; Mon, 7 Jun 2010 05:27:14 -0400 Date: Mon, 7 Jun 2010 12:22:41 +0300 From: "Michael S. Tsirkin" Message-ID: <20100607092241.GA5799@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [Qemu-devel] [PATCHv2] virtio-net: truncating packet List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org virtio net attempts to peek into virtio queue to determine that we have enough space for the complete packet to fit. However, it fails to account for space consumed by virtio net header when it does this, under stress this results in a failure with the message 'truncating packet'. redhat bz 591494. Signed-off-by: Michael S. Tsirkin --- Changes from v1: whitespace fixed. hw/virtio-net.c | 15 +++++++++------ 1 files changed, 9 insertions(+), 6 deletions(-) diff --git a/hw/virtio-net.c b/hw/virtio-net.c index 67eebcf..ede71e3 100644 --- a/hw/virtio-net.c +++ b/hw/virtio-net.c @@ -532,16 +532,17 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_ if (!virtio_net_can_receive(&n->nic->nc)) return -1; - if (!virtio_net_has_buffers(n, size)) + /* hdr_len refers to the header we supply to the guest */ + hdr_len = n->mergeable_rx_bufs ? + sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr); + + + if (!virtio_net_has_buffers(n, size + hdr_len)) return 0; if (!receive_filter(n, buf, size)) return size; - /* hdr_len refers to the header we supply to the guest */ - hdr_len = n->mergeable_rx_bufs ? - sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr); - offset = i = 0; while (offset < size) { @@ -555,7 +556,9 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_ virtqueue_pop(n->rx_vq, &elem) == 0) { if (i == 0) return -1; - fprintf(stderr, "virtio-net truncating packet\n"); + fprintf(stderr, "virtio-net truncating packet: " + "offset %zd, size %zd, hdr %zd\n", + offset, size, hdr_len); exit(1); } -- 1.7.1.12.g42b7f