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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 <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2012-09-24 13:17:13 +02:00
parent 22cc84db6e
commit 63c5872873
1 changed files with 14 additions and 11 deletions

25
hw/virtio-net.c
View File

@ -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);