Re: [PATCH 2/2] kvm tools: Add virtio-9p

Pekka Enberg
2011-05-18T06:38:51Z

On Tue, May 17, 2011 at 9:35 PM, Sasha Levin <levinsasha928@gmail.com> wrote:
> Overview:
> 9p allows for simple RPC based resource sharing over
> different transports (in our case, virtio).
>
> This is the implementation of (most of) the original
> 9p2000 protocol, without the .u or the .l extensions.
>
> How to use:
> 1. Make sure kernel is compiled with:
>    CONFIG_NET_9P=y
>    CONFIG_NET_9P_VIRTIO=y
>    CONFIG_NET_9P_DEBUG=y (At least until code is stable)
>    CONFIG_9P_FS=y
>
> 2. Start KVM with '--virtio-9p <dirname>'. What happens now is that
> a virtio transport with the name 'kvm_9p' is created. The server side
> of the transport maps dirname to the root of the file system.
>
> 3. Within the guest, mount the fs:
> mount -t 9p -otrans=virtio kvm_9p <local_dir> -oversion=9p2000
> This will mount the 9p server to local_dir.

This is really cool, Sasha! I'd like to see host "/" mounted as
"/host" automatically in the guest. If that's too radical, we could go
for mounting $HOME. I guess it's pretty trivial to do on the
hypervisor side but can we do that for unmodified guests (not
necessarily unmodified guest kernels, though)?

Pekka