On 01/24/2011 10:15 AM, Aneesh Kumar K. V wrote: > On Sun, 23 Jan 2011 13:33:14 -0600, Rob Landley <r...@landley.net> wrote: >> 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: > > With top of the kernel tree 52cfd503ad7176d23a5dd7af3981744feb60622f > I am able to build the kernel without CONFIG_VIRTIO_PCI. What is the > exact error you are finding ?
It wasn't a runtime error, it's that some of the config symbols the instructions told me to switch on were hidden. CONFIG_NET_9P_VIRTIO depends on CONFIG_VIRTIO which is selected by CONFIG_VIRTIO_PCI. If CONFIG_VIRTIO isn't forced on by something, you can't select CONFIG_NET_9P_VIRTIO. >> >> -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?) >> > > Are you running qemu as root ? Nope, I try to avoid doing that where possible. > Using passthrough security model require > the ability to change the ownership of the file. Otherwise you can use > security=none, but the credentials with which files are created will > not be correct. Yup, that was it. I note that security=mapped behaves like security=passthrough. (Which is a pity, because it would have been the first legitimate use for extended attributes I've seen since I stopped using OS/2.) > -aneesh It works! Thanks. Rob