Re: [Qemu-devel] Re: RFC: blockdev_add & friends, brief rationale, QMP docs

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 31 May 2010 13:05:37 +0200
Markus Armbruster <armbru@redhat.com> wrote:

> Avi Kivity <avi@redhat.com> writes:
> 
> > On 05/28/2010 10:24 PM, Luiz Capitulino wrote:
> >>
> >>> If a password is needed, we should throw an error and let the QMP client
> >>> set the password and try again.
> >>>      
> >>   It's what we do today, a password should be set with block_passwd before
> >> issuing the change command. Otherwise an error is throw.
> >>    
> >
> > Is the password some kind of global or per-monitor property?  In that
> > case it doesn't work with parallel execution of commands; better to
> > have a password field (or assign IDs to passwords and require a
> > passwordid=... argument).
> 
> It sets the password in the host BlockDriverState.  Which must already
> exist, i.e. you do it after blockdev_add.
> 
> What happens if the guest device accesses the host drive before the key
> is set?

 It's supposed to fail, right Kevin?

> 
> Anything wrong with passing the password as argument?  Did we avoid that
> to protect naive users from exposing their password via argv[]?  That
> "argument" doesn't apply to QMP.
>