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Date: Sat, 07 Nov 2009 13:23:18 +0200
From: Avi Kivity <avi@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 0/4] net-bridge: rootless bridge support
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To: Jamie Lokier <jamie@shareable.org>
Cc: Mark McLoughlin <markmc@redhat.com>, Anthony Liguori <aliguori@us.ibm.com>, Arnd Bergmann <arndbergmann@googlemail.com>, agl@linux.vnet.ibm.com, Arnd Bergmann <arnd@arndb.de>, Juan Quintela <quintela@redhat.com>, Dustin Kirkland <kirkland@canonical.com>, qemu-devel@nongnu.org, Michael Tsirkin <mst@redhat.com>

On 11/07/2009 12:44 PM, Jamie Lokier wrote:
> Aiee - what's the plan?  Can a running KVM be forked, as in into two
> separate processes to run the forked guests in parallel, or not?
>    

kvm fds do not support fork().  Nothing prevents you from stopping the 
guest, reading guest state, fork()ing, and creating a new VM in the 
child with the same state, then restarting both instances.

qemu in general cannot be forked; the two instances would trample on 
each others disk images, host network connections (i.e. vnc, X, the 
monitor), guest network connections, etc.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.