| Message ID | 20210325150735.1098387-6-groug@kaod.org |
|---|---|
| State | New |
| Headers | show |
| Series | virtio: Improve boot time of virtio-scsi-pci and virtio-blk-pci | expand |
On Thu, Mar 25, 2021 at 04:07:32PM +0100, Greg Kurz wrote: > When dataplane multiqueue support was added in QEMU 2.7, the path > that would rollback guest notifiers assignment in case of error > simply got dropped. > > Later on, when Error was added to blk_set_aio_context() in QEMU 4.1, > another error path was introduced, but it ommits to rollback both > host and guest notifiers. > > It seems cleaner to fix the rollback path in one go. The patch is > simple enough that it can be adjusted if backported to a pre-4.1 > QEMU. > > Fixes: 51b04ac5c6a6 ("virtio-blk: dataplane multiqueue support") > Cc: stefanha@redhat.com > Fixes: 97896a4887a0 ("block: Add Error to blk_set_aio_context()") > Cc: kwolf@redhat.com > Signed-off-by: Greg Kurz <groug@kaod.org> > --- > hw/block/dataplane/virtio-blk.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index e9050c8987e7..d7b5c95d26d9 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -207,7 +207,7 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i); } - goto fail_guest_notifiers; + goto fail_host_notifiers; } } @@ -221,7 +221,7 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) aio_context_release(old_context); if (r < 0) { error_report_err(local_err); - goto fail_guest_notifiers; + goto fail_aio_context; } /* Process queued requests before the ones in vring */ @@ -245,6 +245,13 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) aio_context_release(s->ctx); return 0; + fail_aio_context: + for (i = 0; i < nvqs; i++) { + virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); + virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i); + } + fail_host_notifiers: + k->set_guest_notifiers(qbus->parent, nvqs, false); fail_guest_notifiers: /* * If we failed to set up the guest notifiers queued requests will be
When dataplane multiqueue support was added in QEMU 2.7, the path that would rollback guest notifiers assignment in case of error simply got dropped. Later on, when Error was added to blk_set_aio_context() in QEMU 4.1, another error path was introduced, but it ommits to rollback both host and guest notifiers. It seems cleaner to fix the rollback path in one go. The patch is simple enough that it can be adjusted if backported to a pre-4.1 QEMU. Fixes: 51b04ac5c6a6 ("virtio-blk: dataplane multiqueue support") Cc: stefanha@redhat.com Fixes: 97896a4887a0 ("block: Add Error to blk_set_aio_context()") Cc: kwolf@redhat.com Signed-off-by: Greg Kurz <groug@kaod.org> --- hw/block/dataplane/virtio-blk.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)