diff options
| author | Jason Wang <jasowang@redhat.com> | 2015-07-17 15:19:18 +0800 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2015-07-20 14:19:41 +0300 |
| commit | feb93f361739071778ca2d23df3876db399548f7 (patch) | |
| tree | 4e343f13bc3292507b1e08e6cc5f8c29def4f552 | |
| parent | d345ed2da3279b015605823397235b8c5ca5251f (diff) | |
virtio-net: unbreak any layout
Commit 032a74a1c0fcdd5fd1c69e56126b4c857ee36611
("virtio-net: byteswap virtio-net header") breaks any layout by
requiring out_sg[0].iov_len >= n->guest_hdr_len. Fixing this by
copying header to temporary buffer if swap is needed, and then use
this buffer as part of out_sg.
Fixes 032a74a1c0fcdd5fd1c69e56126b4c857ee36611
("virtio-net: byteswap virtio-net header")
Cc: qemu-stable@nongnu.org
Cc: clg@fr.ibm.com
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
| -rw-r--r-- | hw/net/virtio-net.c | 23 | ||||
| -rw-r--r-- | include/hw/virtio/virtio-access.h | 9 |
2 files changed, 27 insertions, 5 deletions
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index e3c2db3250..9f7e91ddce 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1142,7 +1142,8 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) ssize_t ret, len; unsigned int out_num = elem.out_num; struct iovec *out_sg = &elem.out_sg[0]; - struct iovec sg[VIRTQUEUE_MAX_SIZE]; + struct iovec sg[VIRTQUEUE_MAX_SIZE], sg2[VIRTQUEUE_MAX_SIZE + 1]; + struct virtio_net_hdr_mrg_rxbuf mhdr; if (out_num < 1) { error_report("virtio-net header not in first element"); @@ -1150,13 +1151,25 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) } if (n->has_vnet_hdr) { - if (out_sg[0].iov_len < n->guest_hdr_len) { + if (iov_to_buf(out_sg, out_num, 0, &mhdr, n->guest_hdr_len) < + n->guest_hdr_len) { error_report("virtio-net header incorrect"); exit(1); } - virtio_net_hdr_swap(vdev, (void *) out_sg[0].iov_base); + if (virtio_needs_swap(vdev)) { + virtio_net_hdr_swap(vdev, (void *) &mhdr); + sg2[0].iov_base = &mhdr; + sg2[0].iov_len = n->guest_hdr_len; + out_num = iov_copy(&sg2[1], ARRAY_SIZE(sg2) - 1, + out_sg, out_num, + n->guest_hdr_len, -1); + if (out_num == VIRTQUEUE_MAX_SIZE) { + goto drop; + } + out_num += 1; + out_sg = sg2; + } } - /* * If host wants to see the guest header as is, we can * pass it on unchanged. Otherwise, copy just the parts @@ -1186,7 +1199,7 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) } len += ret; - +drop: virtqueue_push(q->tx_vq, &elem, 0); virtio_notify(vdev, q->tx_vq); diff --git a/include/hw/virtio/virtio-access.h b/include/hw/virtio/virtio-access.h index cee5dd70c9..1ec1dfdb6c 100644 --- a/include/hw/virtio/virtio-access.h +++ b/include/hw/virtio/virtio-access.h @@ -143,6 +143,15 @@ static inline uint64_t virtio_ldq_p(VirtIODevice *vdev, const void *ptr) } } +static inline bool virtio_needs_swap(VirtIODevice *vdev) +{ +#ifdef HOST_WORDS_BIGENDIAN + return virtio_access_is_big_endian(vdev) ? false : true; +#else + return virtio_access_is_big_endian(vdev) ? true : false; +#endif +} + static inline uint16_t virtio_tswap16(VirtIODevice *vdev, uint16_t s) { #ifdef HOST_WORDS_BIGENDIAN |