From 63c5872873de8d7d994a589eed7bfe6a70cc8e06 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 24 Sep 2012 13:17:13 +0200 Subject: [PATCH] virtio-net: use safe iov operations for rx Avoid magling iov manually: use safe iov operations for processing packets incoming to guest. This also removes the requirement for virtio header to fit the first s/g entry exactly. Signed-off-by: Michael S. Tsirkin --- hw/virtio-net.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/hw/virtio-net.c b/hw/virtio-net.c index 84615869cb..d315fdf0a4 100644 --- a/hw/virtio-net.c +++ b/hw/virtio-net.c @@ -594,8 +594,9 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size) static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t size) { VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque; - struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL; - const struct iovec *sg = elem.in_sg; + struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE]; + struct virtio_net_hdr_mrg_rxbuf mhdr; + unsigned mhdr_cnt = 0; size_t offset, i, guest_offset; if (!virtio_net_can_receive(&n->nic->nc)) @@ -633,14 +634,13 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t exit(1); } - if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != n->guest_hdr_len) { - error_report("virtio-net header not in first element"); - exit(1); - } - if (i == 0) { - if (n->mergeable_rx_bufs) - mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base; + if (n->mergeable_rx_bufs) { + mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg), + sg, elem.in_num, + offsetof(typeof(mhdr), num_buffers), + sizeof(mhdr.num_buffers)); + } offset += receive_header(n, sg, elem.in_num, buf + offset, size - offset); @@ -673,8 +673,11 @@ static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t virtqueue_fill(n->rx_vq, &elem, total, i++); } - if (mhdr) { - stw_p(&mhdr->num_buffers, i); + if (mhdr_cnt) { + stw_p(&mhdr.num_buffers, i); + iov_from_buf(mhdr_sg, mhdr_cnt, + 0, + &mhdr.num_buffers, sizeof mhdr.num_buffers); } virtqueue_flush(n->rx_vq, i);