diff options
Diffstat (limited to 'hw/block/dataplane/virtio-blk.c')
| -rw-r--r-- | hw/block/dataplane/virtio-blk.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index cd81893d1d..252c3a7a23 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -198,6 +198,10 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) goto fail_guest_notifiers; } + /* + * Batch all the host notifiers in a single transaction to avoid + * quadratic time complexity in address_space_update_ioeventfds(). + */ memory_region_transaction_begin(); /* Set up virtqueue notify */ @@ -211,6 +215,10 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); } + /* + * The transaction expects the ioeventfds to be open when it + * commits. Do it now, before the cleanup loop. + */ memory_region_transaction_commit(); while (j--) { @@ -330,12 +338,20 @@ void virtio_blk_data_plane_stop(VirtIODevice *vdev) aio_context_release(s->ctx); + /* + * Batch all the host notifiers in a single transaction to avoid + * quadratic time complexity in address_space_update_ioeventfds(). + */ memory_region_transaction_begin(); for (i = 0; i < nvqs; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); } + /* + * The transaction expects the ioeventfds to be open when it + * commits. Do it now, before the cleanup loop. + */ memory_region_transaction_commit(); for (i = 0; i < nvqs; i++) { |