On Tue, Jul 16, 2019 at 03:38:09AM +0000, Oleinik, Alexander wrote:
> virtio-net checks that the "out" sg is longer than the guest header, but
> this check can be skipped if has_net_hdr is 0. Also perform this check
> if host_hdr_len != guest_hdr_len
This explanation is way less clear than what you have in 0/1.
I suggest you just move the log here.
>
> Signed-off-by: Alexander Oleinik <alx...@bu.edu>
> ---
> hw/net/virtio-net.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index b9e1cd71cf..46d715b4f5 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -2064,7 +2064,18 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
> */
> assert(n->host_hdr_len <= n->guest_hdr_len);
> if (n->host_hdr_len != n->guest_hdr_len) {
> - unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
> + unsigned sg_num;
> +
> + if (!n->has_vnet_hdr) {
> + if (iov_to_buf(out_sg, out_num, 0, &mhdr, n->guest_hdr_len) <
> + n->guest_hdr_len) {
> + virtio_error(vdev, "virtio-net header incorrect");
> + virtqueue_detach_element(q->tx_vq, elem, 0);
> + g_free(elem);
> + return -EINVAL;
> + }
> + }
This code is duplicated from above. I also suspect some parts are missing
here (such as header endian-ness swap).
Pls find a way not to duplicate the code.
> + sg_num = iov_copy(sg, ARRAY_SIZE(sg),
> out_sg, out_num,
> 0, n->host_hdr_len);
> sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
> --
> 2.20.1
