From ad57f700f469ba1b621274053973f76f8f97cf83 Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Sun, 28 Apr 2024 16:00:52 +0900 Subject: virtio-net: Copy header only when necessary The copied header is only used for byte swapping. Signed-off-by: Akihiko Odaki Signed-off-by: Jason Wang --- hw/net/virtio-net.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) (limited to 'hw/net') diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index a8db8bf..13a17a1 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -360,7 +360,8 @@ static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status) * can't do it, we fallback onto fixing the headers in the core * virtio-net code. */ - n->needs_vnet_hdr_swap = virtio_net_set_vnet_endian(vdev, n->nic->ncs, + n->needs_vnet_hdr_swap = n->has_vnet_hdr && + virtio_net_set_vnet_endian(vdev, n->nic->ncs, queue_pairs, true); } else if (virtio_net_started(n, vdev->status)) { /* After using the device, we need to reset the network backend to @@ -2751,7 +2752,7 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) return -EINVAL; } - if (n->has_vnet_hdr) { + if (n->needs_vnet_hdr_swap) { if (iov_to_buf(out_sg, out_num, 0, &vhdr, n->guest_hdr_len) < n->guest_hdr_len) { virtio_error(vdev, "virtio-net header incorrect"); @@ -2759,19 +2760,16 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) g_free(elem); return -EINVAL; } - if (n->needs_vnet_hdr_swap) { - virtio_net_hdr_swap(vdev, (void *) &vhdr); - sg2[0].iov_base = &vhdr; - 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; + virtio_net_hdr_swap(vdev, (void *) &vhdr); + sg2[0].iov_base = &vhdr; + 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 -- cgit v1.1