From cffcb61add562dbe023ab6c7ba0acd9519fd2202 Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Mon, 10 Aug 2015 05:09:34 +0200 Subject: [PATCH 13/16] virtio-net: remove virtio queues if the guest doesn't support multiqueue Message-id: <1439183375-4841-14-git-send-email-jasowang@redhat.com> Patchwork-id: 67440 O-Subject: [RHEL7.2 qemu-kvm-rhev PATCH 13/14] virtio-net: remove virtio queues if the guest doesn't support multiqueue Bugzilla: 1248312 RH-Acked-by: Vlad Yasevich RH-Acked-by: Paolo Bonzini RH-Acked-by: Michael S. Tsirkin From: Wen Congyang commit da51a335 adds all queues in .realize(). But if the guest doesn't support multiqueue, we forget to remove them. And we cannot handle the ctrl vq corretly. The guest will hang. Signed-off-by: Wen Congyang Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang (cherry picked from commit f9d6dbf0bf6e91b8ed896369ab1b7e91e5a1a4df) Signed-off-by: Miroslav Rezanina --- hw/net/virtio-net.c | 110 +++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 82 insertions(+), 28 deletions(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index d60ce70..6fdc3d5 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1330,9 +1330,86 @@ static void virtio_net_tx_bh(void *opaque) } } +static void virtio_net_add_queue(VirtIONet *n, int index) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(n); + + n->vqs[index].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx); + if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) { + n->vqs[index].tx_vq = + virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer); + n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, + virtio_net_tx_timer, + &n->vqs[index]); + } else { + n->vqs[index].tx_vq = + virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh); + n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]); + } + + n->vqs[index].tx_waiting = 0; + n->vqs[index].n = n; +} + +static void virtio_net_del_queue(VirtIONet *n, int index) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(n); + VirtIONetQueue *q = &n->vqs[index]; + NetClientState *nc = qemu_get_subqueue(n->nic, index); + + qemu_purge_queued_packets(nc); + + virtio_del_queue(vdev, index * 2); + if (q->tx_timer) { + timer_del(q->tx_timer); + timer_free(q->tx_timer); + } else { + qemu_bh_delete(q->tx_bh); + } + virtio_del_queue(vdev, index * 2 + 1); +} + +static void virtio_net_change_num_queues(VirtIONet *n, int new_max_queues) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(n); + int old_num_queues = virtio_get_num_queues(vdev); + int new_num_queues = new_max_queues * 2 + 1; + int i; + + assert(old_num_queues >= 3); + assert(old_num_queues % 2 == 1); + + if (old_num_queues == new_num_queues) { + return; + } + + /* + * We always need to remove and add ctrl vq if + * old_num_queues != new_num_queues. Remove ctrl_vq first, + * and then we only enter one of the following too loops. + */ + virtio_del_queue(vdev, old_num_queues - 1); + + for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) { + /* new_num_queues < old_num_queues */ + virtio_net_del_queue(n, i / 2); + } + + for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) { + /* new_num_queues > old_num_queues */ + virtio_net_add_queue(n, i / 2); + } + + /* add ctrl_vq last */ + n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl); +} + static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) { + int max = multiqueue ? n->max_queues : 1; + n->multiqueue = multiqueue; + virtio_net_change_num_queues(n, max); virtio_net_set_queues(n); } @@ -1607,21 +1684,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) } for (i = 0; i < n->max_queues; i++) { - n->vqs[i].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx); - if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) { - n->vqs[i].tx_vq = - virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer); - n->vqs[i].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, - virtio_net_tx_timer, - &n->vqs[i]); - } else { - n->vqs[i].tx_vq = - virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh); - n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[i]); - } - - n->vqs[i].tx_waiting = 0; - n->vqs[i].n = n; + virtio_net_add_queue(n, i); } n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl); @@ -1675,7 +1738,7 @@ static void virtio_net_device_unrealize(DeviceState *dev, Error **errp) { VirtIODevice *vdev = VIRTIO_DEVICE(dev); VirtIONet *n = VIRTIO_NET(dev); - int i; + int i, max_queues; /* This will stop vhost backend if appropriate. */ virtio_net_set_status(vdev, 0); @@ -1690,18 +1753,9 @@ static void virtio_net_device_unrealize(DeviceState *dev, Error **errp) g_free(n->mac_table.macs); g_free(n->vlans); - for (i = 0; i < n->max_queues; i++) { - VirtIONetQueue *q = &n->vqs[i]; - NetClientState *nc = qemu_get_subqueue(n->nic, i); - - qemu_purge_queued_packets(nc); - - if (q->tx_timer) { - timer_del(q->tx_timer); - timer_free(q->tx_timer); - } else if (q->tx_bh) { - qemu_bh_delete(q->tx_bh); - } + max_queues = n->multiqueue ? n->max_queues : 1; + for (i = 0; i < max_queues; i++) { + virtio_net_del_queue(n, i); } timer_del(n->announce_timer); -- 1.8.3.1