Re: [libvirt] [Qemu-devel] [PATCH v2 3/3] raw-posix: Re-open host CD-ROM after media change

On 04/04/2011 05:47 AM, Daniel P. Berrange wrote: >>I'm hoping libvirt's behavior can be made to just work rather than >>adding new features to QEMU. But perhaps passing file descriptors is >>useful for more than just reopening host devices. This would >>basically be a privilege separation model where the QEMU process isn't >>able to open files itself but can request libvirt to open them on its >>behalf. >It is rather frickin' annoying the way udev resets the ownership >when the media merely changes. If it isn't possible to stop udev >doing this, then i think the only practical thing is to use ACLs >instead of user/group ownership. We wanted to switch to ACLs in >libvirt for other reasons already, but it isn't quite as simple >as it sounds[1] so we've not done it just yet. Isn't the root of the problem that you're not running a guest in the expected security context?

How much of a leap would it be to spawn a guest with the credentials of the user that created/defined it? Or better yet, to let the user be specified in the XML.