From 6e85af9b5b8f05fc18fe9f60326de675065d18df Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sun, 6 Jun 2010 18:53:10 +0300 Subject: virtio-net: truncating packet 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 --- hw/virtio-net.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/hw/virtio-net.c b/hw/virtio-net.c index 6a9d560a9b..06ba48103d 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_len %zd\n", + offset, size, hdr_len); exit(1); } -- cgit v1.2.3