diff options
author | Stefan Hajnoczi <stefanha@redhat.com> | 2023-05-16 15:02:35 -0400 |
---|---|---|
committer | Kevin Wolf <kwolf@redhat.com> | 2023-05-30 17:32:02 +0200 |
commit | 1665d9326fd2dd97f1f4061decd67702956ec53c (patch) | |
tree | afd5f39ade36feebdc930fc30d6a84dc126e9290 /hw/block | |
parent | bd58ab40c3fcfdd94f5524626ae13c43818bd23a (diff) | |
download | qemu-1665d9326fd2dd97f1f4061decd67702956ec53c.zip qemu-1665d9326fd2dd97f1f4061decd67702956ec53c.tar.gz qemu-1665d9326fd2dd97f1f4061decd67702956ec53c.tar.bz2 |
virtio-blk: implement BlockDevOps->drained_begin()
Detach ioeventfds during drained sections to stop I/O submission from
the guest. virtio-blk is no longer reliant on aio_disable_external()
after this patch. This will allow us to remove the
aio_disable_external() API once all other code that relies on it is
converted.
Take extra care to avoid attaching/detaching ioeventfds if the data
plane is started/stopped during a drained section. This should be rare,
but maybe the mirror block job can trigger it.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230516190238.8401-18-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'hw/block')
-rw-r--r-- | hw/block/dataplane/virtio-blk.c | 16 | ||||
-rw-r--r-- | hw/block/virtio-blk.c | 38 |
2 files changed, 47 insertions, 7 deletions
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index 4f5c7cd..b90456c 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -246,13 +246,15 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) } /* Get this show started by hooking up our callbacks */ - aio_context_acquire(s->ctx); - for (i = 0; i < nvqs; i++) { - VirtQueue *vq = virtio_get_queue(s->vdev, i); + if (!blk_in_drain(s->conf->conf.blk)) { + aio_context_acquire(s->ctx); + for (i = 0; i < nvqs; i++) { + VirtQueue *vq = virtio_get_queue(s->vdev, i); - virtio_queue_aio_attach_host_notifier(vq, s->ctx); + virtio_queue_aio_attach_host_notifier(vq, s->ctx); + } + aio_context_release(s->ctx); } - aio_context_release(s->ctx); return 0; fail_aio_context: @@ -322,7 +324,9 @@ void virtio_blk_data_plane_stop(VirtIODevice *vdev) s->stopping = true; trace_virtio_blk_data_plane_stop(s); - aio_wait_bh_oneshot(s->ctx, virtio_blk_data_plane_stop_bh, s); + if (!blk_in_drain(s->conf->conf.blk)) { + aio_wait_bh_oneshot(s->ctx, virtio_blk_data_plane_stop_bh, s); + } aio_context_acquire(s->ctx); diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 8f65ea4..4ca66b5 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1506,8 +1506,44 @@ static void virtio_blk_resize(void *opaque) aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); } +/* Suspend virtqueue ioeventfd processing during drain */ +static void virtio_blk_drained_begin(void *opaque) +{ + VirtIOBlock *s = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); + AioContext *ctx = blk_get_aio_context(s->conf.conf.blk); + + if (!s->dataplane || !s->dataplane_started) { + return; + } + + for (uint16_t i = 0; i < s->conf.num_queues; i++) { + VirtQueue *vq = virtio_get_queue(vdev, i); + virtio_queue_aio_detach_host_notifier(vq, ctx); + } +} + +/* Resume virtqueue ioeventfd processing after drain */ +static void virtio_blk_drained_end(void *opaque) +{ + VirtIOBlock *s = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); + AioContext *ctx = blk_get_aio_context(s->conf.conf.blk); + + if (!s->dataplane || !s->dataplane_started) { + return; + } + + for (uint16_t i = 0; i < s->conf.num_queues; i++) { + VirtQueue *vq = virtio_get_queue(vdev, i); + virtio_queue_aio_attach_host_notifier(vq, ctx); + } +} + static const BlockDevOps virtio_block_ops = { - .resize_cb = virtio_blk_resize, + .resize_cb = virtio_blk_resize, + .drained_begin = virtio_blk_drained_begin, + .drained_end = virtio_blk_drained_end, }; static void virtio_blk_device_realize(DeviceState *dev, Error **errp) |