Re: [Qemu-devel] [PATCH-RFC 00/13] vhost-net: preview

[Daniel P. Berrange]

On Mon, Jan 11, 2010 at 07:16:42PM +0200, Michael S. Tsirkin wrote:
> Here's an untested patchset with vhost support for upstream qemu.  Note
> that you should not expect performance gains from vhost unless in-kernel
> irqchip is enabled (which is not in upstream qemu now).  Since adding
> vhost involves quite a bit of infrastructure, I thought it makes sense
> to send an RFC already, so that interested parties can review it.  In
> particular, command line and help text need to be finalized early to so
> that management can start looking on supporting the feature. This patch
> has all bits besides migration filled in. Also missing is packet socket
> backend: another team is now working on this.

Can you clarify a question about migration for me. Is it possible to
live migrate a guest configured with tap + bridge on one machine over
to another where it is launched with vhost + bridge, and vice-versa.
In other words does this vhost support have any guest visible impact
that would cause migraiton compatability problems, or it is purely a
host side optimization like vnet_hdr was ?

Regards,
Daniel
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