[Qemu-devel] Playing with virtfs.

[Rob Landley <rob@landley.net>]

Using yesterday's -git, following the instructions in
http://wiki.qemu.org/Documentation/9psetup (which is missing a kernel
symbol, you need to add CONFIG_VIRTIO_PCI to your kernel too), I managed
to mount a read-only virtfs filesystem, adding this to the
qemu-system-x86_64 command line:

-virtfs
local,security_model=passthrough,mount_tag=kvm,path=/home/landley/9ptest

And then in the emulated Linux:

  root@kvm:~# mount -t 9p -o trans=virtio,version=9p2000.L kvm woot
  root@kvm:~# ls -l woot
  total 80
  -rw-r--r-- 1 1000 1000 77874 Jan 22 23:33 config-linux
  root@kvm:~# cd woot
  root@kvm:~/woot# touch fred
  touch: setting times of `fred': No such file or directory
  root@kvm:~/woot#

I.E. It seems to work fine read only, but changes are discarded.

Am I doing something wrong, or is this expected?  (If so, when is write
support likely to go in?)

Rob