On Mon, May 17, 2021 at 03:26:37PM +0200, Greg Kurz wrote: > The device model batching its ioeventfds in a single MR transaction is > an optimization. Clarify this in virtio-scsi, virtio-blk and generic > virtio code. Also clarify that the transaction must commit before > closing ioeventfds so that no one is tempted to merge the loops > in the start functions error path and in the stop functions. > > Signed-off-by: Greg Kurz > --- > > I'm posting this because the wrong version of my "virtio: Improve boot > time of virtio-scsi-pci and virtio-blk-pci" series as explained here: > > https://lists.nongnu.org/archive/html/qemu-devel/2021-05/msg04744.html > > While here, I'm also adding the comments to the core virtio code, which > also does batching since commit 710fccf80d78 ("virtio: improve virtio > devices initialization time"). > --- > hw/block/dataplane/virtio-blk.c | 16 ++++++++++++++++ > hw/scsi/virtio-scsi-dataplane.c | 16 ++++++++++++++++ > hw/virtio/virtio.c | 16 ++++++++++++++++ > 3 files changed, 48 insertions(+) Reviewed-by: Stefan Hajnoczi