Public bug reported: Using virt-manager and libvirtd, I added a VirtFS filesystem passthrough to an existing qemu virtual machine also running Ubuntu.
The XML code generated by libvirt looks like this: <filesystem type='mount' accessmode='mapped'> <source dir='/p9test'/> <target dir='p9_mapped'/> <alias name='fs0'/> <address type='pci' domain='0x0000' bus='0x02' slot='0x06' function='0x0'/> </filesystem> Inside the VM, I am able to mount the filesystem passthrough like this: mount -t 9p -o trans=virtio,version=9p2000.L,rw p9_mapped /mnt After mounting, it is possible to read the contents of the passthrough, but it is not possible to write into the directory. E.g. 'touch /mnt/test' results in the error: touch: cannot touch ‘/mnt/test’: Permission denied Using the other p9 access modes 'passthrough' and 'squash' also does not work. Read is possible, write isn't. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: libvirt-bin 1.3.1-1ubuntu6 ProcVersionSignature: Ubuntu 4.4.0-13.29-generic 4.4.5 Uname: Linux 4.4.0-13-generic x86_64 ApportVersion: 2.20-0ubuntu3 Architecture: amd64 CurrentDesktop: Unity Date: Fri Mar 18 22:12:34 2016 SourcePackage: libvirt UpgradeStatus: Upgraded to xenial on 2016-02-06 (41 days ago) modified.conffile..etc.libvirt.qemu.conf: [inaccessible: [Errno 13] Keine Berechtigung: '/etc/libvirt/qemu.conf'] modified.conffile..etc.libvirt.qemu.networks.default.xml: [inaccessible: [Errno 13] Keine Berechtigung: '/etc/libvirt/qemu/networks/default.xml'] ** Affects: libvirt (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apparmor apport-bug libvirt p9 qemu xenial ** Tags added: libvirt p9 qemu -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1559317 Title: [xenial] No write access to VirtFS (p9) in qemu VM run by libvirt To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1559317/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs