From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 2/3] virtio-pci: Use ioeventfd for virtqueue notify
Date: Thu, 11 Nov 2010 11:45:18 -0500
Message-ID: <20101111164518.GA28773@infradead.org>
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Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org,
	"Michael S. Tsirkin" <mst@redhat.com>
To: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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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.