Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels

[Sasha Levin]

On Tue, Nov 8, 2011 at 4:52 PM, Christoph Hellwig <address@hidden> wrote:
> On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote:
>> On 11/06/2011 03:35 AM, Alexander Graf wrote:
>> > To quickly get going, just execute the following as user:
>> >
>> >     $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash
>> >
>> > This will drop you into a shell on your rootfs.
>> >
>>
>> Doesn't work on Fedora 15.  F15's qemu-kvm doesn't have -machine or
>> -virtfs.  Even qemu.git on F15 won't build virtfs since xattr.h
>> detection is broken (patch posted).
>
> Nevermind that running virtfs as a rootfs is a really dumb idea.  You
> do now want to run a VM that has a rootfs that gets changed all the
> time behind your back.
>
> Running qemu -snapshot on the actual root block device is the only
> safe way to reuse the host installation, although it gets a bit
> complicated if people have multiple devices mounted into the namespace.

Using block devices also requires root.