Re: [libvirt] need custom /dev entries in LXC
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 :| -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] need custom /dev entries in LXC
On 06/03/2013 06:03 AM, Daniel P. Berrange wrote: 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 Thanks for the response, Daniel. That's good news. -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
[libvirt] need custom /dev entries in LXC
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? Thanks, - Michael R. Hines -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
