On Tue, Mar 14, 2017 at 05:35:54PM -0400, Daniel J Walsh wrote: > > > On 03/14/2017 05:18 PM, Dusty Mabe wrote: > > > > On 03/14/2017 05:15 PM, Daniel J Walsh wrote: > >> > >> On 03/14/2017 05:02 PM, Dusty Mabe wrote: > >>> On 03/14/2017 04:56 PM, Daniel J Walsh wrote: > >>>> On 03/14/2017 04:29 PM, Daniel P. Berrange wrote: > >>>> I guess if you volume/bind mount the device into the container you could > >>>> see an issue, > >>>> but most containers that deal with /dev/kvm are going to be run as root, > >>>> anyways. > >>> I was running with --privileged, still got permission denied until I > >>> changed permissions of /dev/kvm to 666. > >>> _______________________________________________ > >>> devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx > >>> To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx > >> # docker run -ti --device /dev/kvm fedora ls -lZ /dev/kvm > >> crw-rw-rw-. 1 root 36 system_u:object_r:container_file_t:s0:c303,c737 10, 232 Mar 14 21:12 /dev/kvm > >> # chmod 600 /dev/kvm > >> # docker run -ti --device /dev/kvm fedora ls -lZ /dev/kvm > >> crw-------. 1 root 36 system_u:object_r:container_file_t:s0:c281,c442 10, 232 Mar 14 21:13 /dev/kvm > >> > >> So using --device to add the device to the container just maintains the permission of the host > >> for the device you added. Whether it is volume mounted in or specified via --device, at least > >> from dockers point of view. > > I'm not sure of your point. I was just trying to say that whether i > > was root or not did not seem to matter. I still got permission denied > > if perms were 600 and not 666. I'm working off of memory here, so it's > > possible somebody will prove me wrong. > > Most likely libvirt or whoever is launching the containers is not running > as root, so it is being blocked access. It is simpler than that. When you ask libvirt to assign a device to a container it will simply mknod() in the container's private /dev, with permissions 0700. If the container needs to make that available to mon-privileged users inside the container, its "init" has to arrange to set permissions further. For Docker, I'm unclear whether it is also just doing a mknod in the container's /dev, or whether it is bind mounting the host device node. Either way, udev isn't involved inside the container. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :| _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx
