Re: [libvirt] [PATCH] qemu: domain I/O asynchronous handling

On Tue, Jun 14, 2011 at 06:18:17PM +0200, Michal Privoznik wrote: > For virtio disks and interfaces, qemu allows users to enable or disable > ioeventfd feature. This means, qemu can execute domain code, while > another thread waits for I/O event. Basically, in some cases it is win, > in some loss. This feature is available via 'asyncio' attribute in disk > and interface <driver> element. It accepts 'on' and 'off'. Leaving this > attribute out defaults to hypervisor decision. I think this is rather misleading. AFAIK, ioeventfd has absolutely nothing todo with async I/O. There is already a completely different QEMU command line flag which toggles between the two QEMU async I/O implementations, which is set via the 'io=' attribute. So I don't think we can seriously use 'asyncio' for this new feature.