Re: [RFC] Unify KVM kernel-space and user-space code into a single project

Avi Kivity
2010-03-21T21:03:19Z

On 03/21/2010 10:31 PM, Antoine Martin wrote:
> On 03/22/2010 03:24 AM, Avi Kivity wrote:
>> On 03/21/2010 10:18 PM, Antoine Martin wrote:
>>>> That includes the guest kernel. If you can deploy a new kernel in
>>>> the guest, presumably you can deploy a userspace package.
>>>
>>> That's not always true.
>>> The host admin can control the guest kernel via "kvm -kernel" easily
>>> enough, but he may or may not have access to the disk that is used
>>> in the guest. (think encrypted disks, service agreements, etc)
>>
>> There is a matching -initrd argument that you can use to launch a
>> daemon.
> I thought this discussion was about making it easy to deploy... and
> generating a custom initrd isn't easy by any means, and it requires
> access to the guest filesystem (and its mkinitrd tools).

That's true. You need to run mkinitrd anyway, though, unless your guest
is non-modular and non-lvm.

>> I believe that -kernel use will be rare, though. It's a lot easier
>> to keep everything in one filesystem.
> Well, for what it's worth, I rarely ever use anything else. My virtual
> disks are raw so I can loop mount them easily, and I can also switch
> my guest kernels from outside... without ever needing to mount those
> disks.

Curious, what do you use them for?

btw, if you build your kernel outside the guest, then you already have
access to all its symbols, without needing anything further.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.