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Date: Thu, 2 Aug 2012 11:53:19 -0300
From: Luiz Capitulino <lcapitulino@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 13/34] hmp: hmp_change(): don't rely on
 QERR_DEVICE_ENCRYPTED
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kwolf@redhat.com, aliguori@us.ibm.com, mdroth@linux.vnet.ibm.com, qemu-devel@nongnu.org, Markus Armbruster <armbru@redhat.com>, eblake@redhat.com

On Thu, 02 Aug 2012 15:57:24 +0200
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Il 02/08/2012 15:53, Markus Armbruster ha scritto:
> >> > Is this anything that an external application can reproduce?
> >> >
> >> > Perhaps we need to keep QERR_DEVICE_ENCRYPTED even if libvirt does not
> >> > use it, or at least provide an alternative mechanism (e.g. an event) to
> >> > realize its effect.
> > Not sure I get you.
> > 
> > External applications should use QMP.
> 
> Yes.  Is there a conceivable scenario in which a QMP client needs to
> look at QERR_DEVICE_ENCRYPTED?
> 
> > A sane way to change media in QMP needs to provide the key as argument.
> 
> How does the QMP client know that the device is encrypted, and thus they
> have to ask for the key and retry?

It would be interesting to know how libvirt handles this.

> 
> Same for hmp_cont, by the way.
> 
> > If the key is wrong, fail the change cleanly.  In particular, don't
> > eject then.
> 
> Agreed on not ejecting, but this is orthogonal.
> 
> Paolo
>