Re: [Qemu-devel] [PATCH V8 08/14] Introduce file lock for the block layer

[Michael S. Tsirkin]

On Wed, Sep 07, 2011 at 09:06:05AM -0400, Stefan Berger wrote:
> >>First: There are two ways to encrypt the data.
> >>
> >>One comes with the QCoW2 type of image and it comes for free. Set
> >>the encryption flag when creating the QCoW2 file and one has to
> >>provide a key to access the QCoW2. I found this mode problematic for
> >>users since it required me to go through the monitor every time I
> >>started the VM. Besides that the key is provided so late that all
> >>devices are already initialized and if the wrong key was provided
> >>the only thing the TPM can do is to go into shutdown mode since
> >>there is state on the QCoW2 but it cannot be decrypted. This also
> >>became problematic when doing migrations with libvirt for example
> >>and one was to have a wrong key/password installed on the target
> >>side -- graceful termination of the migration is impossible.

OK let's go back to this for a moment. Add a load
callback, access file there. On failure, return
an error. migration fails gracefully, and
management can retry, or migrate to another node,
or whatever.

What's the problem exactly?


-- 
MST