Re: [libvirt] [PATCH v2 00/21] Run qemu under its own namespace

On Mon, Dec 12, 2016 at 11:48:50AM +0000, Daniel P. Berrange wrote: > On Wed, Dec 07, 2016 at 09:36:07AM +0100, Michal Privoznik wrote: >> v1 posted here: >> https://www.redhat.com/archives/libvir-list/2016-November/msg01208.html >> >> diff to v1: >> - I've dropped the patches for hugepages which are posted separately [1] >> - I've reworked some parts according to Dan's suggestions >> - Filled missing impl for virSCSIVHostDevice which was merged meanwhile >> >> Please note that patches 1-5, 7 were ACKed already. >> >> You can also find the patches on my github: >> >> https://github.com/zippy2/libvirt/tree/qemu_container_v3 > > I pulled this branch and aside from the compile error i mention I can't > start guests > > error: internal error: process exited while connecting to monitor: 2016-12-12T11:47:53.740784Z qemu-system-x86_64: -chardev pty,id=charserial0: Failed to create PTY: No such file or directory > > > Without having investigated, I wonder if it is trying to access the > /dev/ptmx file and failing ? The /dev/ptmx file needs to be a symlink > to /dev/pts/ptmx and I'm not seeing code which creates that yet. Ok, in fact it is exactly the opposite problem :-) You have done a bind mount of /dev/pts/ptmx -> /dev/ptmx, which ought to be fine, except on Fedora 25 for some reason the /dev/pts/ptmx file is created c-------- so nothing has privileges to access it. Instead Fedora uses a real /dev/ptmx device node. I guess this way Fedora works is ok, because you only need the /dev/ptmx symlink / bind mount, if we created a *new* devpts mount instance - but we're just reusing the host instance. IOW, just modify qemuDomainBuildNamespace to remove the bind mount of /dev/ptmx entirely, and QEMU starts.

After that, my next problem is lack of /dev/shm break SPICE graphics. We should treat /dev/shm the same way we treat /dev/pts - just preserve the existing host /dev/shm mount point (if it exists)