[Qemu-devel] Re: [PATCH 2/3] virtio-pci: Use ioeventfd for virtqueue notify

[Christoph Hellwig]

On Thu, Nov 11, 2010 at 01:47:21PM +0000, Stefan Hajnoczi wrote:
> Some virtio devices are known to have guest drivers which expect a notify to 
> be
> processed synchronously and spin waiting for completion.  Only enable 
> ioeventfd
> for virtio-blk and virtio-net for now.

Who guarantees that less common virtio-blk and virtio-net guest drivers
for non-Linux OSes are fine with it?  Maybe you should add a feature flag
that the guest has to ACK to enable it.