On Wed, May 22, 2013 at 06:22:12PM -0400, Michael R. Hines wrote:

Hi,

We run nvidia devices inside libvirt-managed LXC containers.

It used to be that simply doing:

$ echo 'c 195:* rwm' > /sys/fs/cgroup/devices/libvirt/lxc

Then, after booting the container, we would do:

$ mknod -m 666 /dev/nvidia0 c 195 0

.... would be good enough to run our CUDA applications.

But, according to:

$ cat src/lxc/lxc_container.c

The CAP_MKNOD capability is being dropped and only a specific set of devices is being created before booting the container.

Is there any reason why this is not per-device configurable?

With recent libvirt you can pass through arbitrary block and character devices explicitly, using the following XML: http://libvirt.org/formatdomain.html#elementsHostDevCaps As such there is never any need to change cgroups or use mknod as you describe. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|