Re: [GIT PULL] Linux KVM tool for v3.7-rc0

[Ingo Molnar <mingo@kernel.org>]

* Markus Trippelsdorf <markus@trippelsdorf.de> wrote:

> On 2012.10.21 at 19:51 +0200, Ingo Molnar wrote:
> > 
> > * Markus Trippelsdorf <markus@trippelsdorf.de> wrote:
> > 
> > > On 2012.10.21 at 19:15 +0200, Borislav Petkov wrote:
> > > > On Sun, Oct 21, 2012 at 05:03:05PM +0200, Ingo Molnar wrote:
> > > > > The best way to compare them would be a script that gives exactly the
> > > > > same test environment that 'vm run' / 'vm sandbox' does out of box,
> > > > > but using qemu.
> > > > >
> > > > > If such a script is available then that would certainly be a useful
> > > > > testing option to kernel developers.
> > > > 
> > > > Right,
> > > > 
> > > > I gotta say, I've mucked around with qemu/kvm net options as a novice
> > > > user and haven't always been successfu. If you get host networking
> > > > straight away in lkvm then that's another clear point for tools/kvm.
> > > > 
> > > > Same holds true for copying data back and forth between host and guest.
> > > 
> > > I'm agnostic about lkvm, but the following command does all the above:
> > > 
> > > qemu-system-x86_64 -enable-kvm -net nic,vlan=0,model=virtio 
> > > -net user -fsdev 
> > > local,security_model=passthrough,id=root,path=/ -device 
> > > virtio-9p-pci,id=root,fsdev=root,mount_tag=/dev/root -m 512 
> > > -smp 2 -kernel /usr/src/linux/arch/x86/boot/bzImage -nographic 
> > > -append "init=/bin/zsh root=/dev/root console=ttyS0 
> > > kgdboc=ttyS0 rootflags=rw,trans=virtio rootfstype=9p ip=dhcp"
> > > 
> > > If you want your host root-fs to be mounted rw (to copy data
> > > back and forth) you need to run to above as root and add "rw"
> > > to the kernel options.
> > 
> > Why does it have to run as root? I run 'vm' unprivileged (other 
> > than /dev/kvm access).
> 
> From the qemu man page:
> 
>  security_model=security_model
> 
>   Specifies the security model to be used for this export 
> path.  Supported security models are "passthrough", "mapped- 
> xattr", "mapped-file" and "none". In "passthrough" security 
> model, files are stored using the same credentials as they are 
> created on the guest. This requires QEMU to run as root.

So I guess running it with 'none' can be used unprivileged?

Thanks,

	Ingo