Re: [PATCH] virtio: don't enable notifications during polling

2019-12-13 Thread Stefan Hajnoczi
On Mon, Dec 09, 2019 at 09:09:57PM +, Stefan Hajnoczi wrote: > Virtqueue notifications are not necessary during polling, so we disable > them. This allows the guest driver to avoid MMIO vmexits. > Unfortunately the virtio-blk and virtio-scsi handler functions re-enable > notifications, defeati

Re: [PATCH] virtio: don't enable notifications during polling

2019-12-11 Thread Stefan Hajnoczi
On Wed, Dec 11, 2019 at 10:58:43AM -0500, Michael S. Tsirkin wrote: > On Mon, Dec 09, 2019 at 09:09:57PM +, Stefan Hajnoczi wrote: > > Virtqueue notifications are not necessary during polling, so we disable > > them. This allows the guest driver to avoid MMIO vmexits. > > Unfortunately the vir

Re: [PATCH] virtio: don't enable notifications during polling

2019-12-11 Thread Michael S. Tsirkin
On Mon, Dec 09, 2019 at 09:09:57PM +, Stefan Hajnoczi wrote: > Virtqueue notifications are not necessary during polling, so we disable > them. This allows the guest driver to avoid MMIO vmexits. > Unfortunately the virtio-blk and virtio-scsi handler functions re-enable > notifications, defeati

[PATCH] virtio: don't enable notifications during polling

2019-12-09 Thread Stefan Hajnoczi
Virtqueue notifications are not necessary during polling, so we disable them. This allows the guest driver to avoid MMIO vmexits. Unfortunately the virtio-blk and virtio-scsi handler functions re-enable notifications, defeating this optimization. Fix virtio-blk and virtio-scsi emulation so they l