Re: [RFC] Unify KVM kernel-space and user-space code into a singleproject

From: Richard W.M. Jones
Date: Mon Mar 22 2010 - 09:24:39 EST


On Mon, Mar 22, 2010 at 01:05:13PM +0000, Daniel P. Berrange wrote:
> This is close to the way libguestfs already works. It boots QEMU/KVM pointing
> to a minimal stripped down appliance linux OS image, containing a small agent
> it talks to over some form of vmchannel/serial/virtio-serial device. Thus the
> kernel in the appliance it runs is the only thing that needs to know about the
> filesystem/lvm/dm on-disk formats - libguestfs definitely does not want to be
> duplicating this detailed knowledge of on disk format itself. It is doing
> full read-write access to the guest filesystem in offline mode - one of the
> major use cases is disaster recovery from a unbootable guest OS image.

As Dan said, the 'daemon' part is separate and could be run as a
standard part of a guest install, talking over vmchannel to the host.
The only real issue I can see is adding access control to the daemon
(currently it doesn't need it and doesn't do any). Doing it this way
you'd be leveraging the ~250,000 lines of existing libguestfs code,
bindings in multiple languages, tools etc.

Rich.

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