From 2eef278b9e6326707410eed23be40e57f6c331b7 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 3 Jul 2017 22:25:24 +0300 Subject: [PATCH] virtio-net: fix tx queue size for !vhost-user Current code segfaults when no nic peer is specified. Fix it up - fall back to default queue size. Fixes: 9b02e1618cf26a ("virtio-net: enable configurable tx queue size") Cc: Wei Wang Signed-off-by: Michael S. Tsirkin --- hw/net/virtio-net.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index a1fc0dbb6d..5630a9ec44 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -498,6 +498,24 @@ static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, } } +static int virtio_net_max_tx_queue_size(VirtIONet *n) +{ + NetClientState *peer = n->nic_conf.peers.ncs[0]; + + /* + * Backends other than vhost-user don't support max queue size. + */ + if (!peer) { + return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE; + } + + if (peer->info->type != NET_CLIENT_DRIVER_VHOST_USER) { + return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE; + } + + return VIRTQUEUE_MAX_SIZE; +} + static int peer_attach(VirtIONet *n, int index) { NetClientState *nc = qemu_get_subqueue(n->nic, index); @@ -1964,14 +1982,8 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) error_report("Defaulting to \"bh\""); } - /* - * Currently, backends other than vhost-user don't support 1024 queue - * size. - */ - if (n->net_conf.tx_queue_size == VIRTQUEUE_MAX_SIZE && - n->nic_conf.peers.ncs[0]->info->type != NET_CLIENT_DRIVER_VHOST_USER) { - n->net_conf.tx_queue_size = VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE; - } + n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n), + n->net_conf.tx_queue_size); for (i = 0; i < n->max_queues; i++) { virtio_net_add_queue(n, i);