Re: [PATCH] kvm tools: Boot to host /bin/sh via 9p by default

[Pekka Enberg <penberg@kernel.org>]

On Tue, 2011-08-09 at 19:59 +0300, Avi Kivity wrote:
> On 08/09/2011 06:33 PM, Pekka Enberg wrote:
> > This patch updates 'kvm run' to boot to host filesystem via 9p '/bin/sh' by
> > default:
> >
> >    $ ./kvm run
> >      # kvm run -k ../../arch/x86/boot/bzImage -m 320 -c 2 --name guest-3462
> >    [    0.000000] Linux version 3.1.0-rc1+ (penberg@tiger) (gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5) ) #7 SMP PREEMPT Tue Aug 9 16:39:20 EEST 2011
> >    [    0.000000] Command line: notsc noapic noacpi pci=conf1 reboot=k panic=1 console=ttyS0 earlyprintk=serial  init=/bin/sh  root=/dev/vda rw  root=/dev/root rootflags=rw,trans=virtio,version=9p2000.u rootfstype=9p
> >
> >    [snip]
> >
> >    [    1.803261] VFS: Mounted root (9p filesystem) on device 0:13.
> >    [    1.805153] devtmpfs: mounted
> >    [    1.808353] Freeing unused kernel memory: 924k freed
> >    [    1.810592] Write protecting the kernel read-only data: 12288k
> >    [    1.816268] Freeing unused kernel memory: 632k freed
> >    [    1.826030] Freeing unused kernel memory: 1448k freed
> >    sh: cannot set terminal process group (-1): Inappropriate ioctl for device
> >    sh: no job control in this shell
> >    sh-4.1#
> >
> 
> Most kernels won't have 9p built-in, so how about building a tiny initrd 
> to load the needed modules?

Sure. Can we do that in portable way across distributions? We already
support the "-i" command line option, btw, if you already have a working
initrd somewhere.

> btw, I get
> 
> # ./kvm run
>    # kvm run -k ../../arch/x86/boot/bzImage -m 1728 -c 24 --name guest-10193
> <hang>

Is that with or without 9p built into the kernel image? There's a full
list of required options in tools/kvm/README.

			Pekka