From 4d17ab219cea7c63c844994306b016757334ac44 Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Thu, 13 Jul 2017 07:20:58 +0200 Subject: [PATCH 2/2] virtio-net: fix tx queue size for !vhost-user RH-Author: Xiao Wang Message-id: <1499930458-9904-3-git-send-email-jasowang@redhat.com> Patchwork-id: 75748 O-Subject: [RHEL7.4z qemu-kvm PATCH 2/2] virtio-net: fix tx queue size for !vhost-user Bugzilla: 1471666 RH-Acked-by: Michael S. Tsirkin RH-Acked-by: Maxime Coquelin RH-Acked-by: wexu@redhat.com From: "Michael S. Tsirkin" 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 (cherry picked from commit 2eef278b9e6326707410eed23be40e57f6c331b7) Signed-off-by: Miroslav Rezanina --- 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 b9b8449..8995703 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -497,6 +497,24 @@ 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); @@ -1960,14 +1978,8 @@ 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); -- 1.8.3.1