Re: [Qemu-devel] [PATCH] proto: add 'shift' extension.

[Denis V. Lunev]

On 09/27/2016 03:07 PM, Paolo Bonzini wrote:
>
> ----- Original Message -----
>> From: "Denis V. Lunev" <address@hidden>
>> To: "Paolo Bonzini" <address@hidden>
>> Cc: "Vladimir Sementsov-Ogievskiy" <address@hidden>, address@hidden, 
>> address@hidden,
>> address@hidden, address@hidden, address@hidden, address@hidden, 
>> address@hidden,
>> address@hidden
>> Sent: Tuesday, September 27, 2016 12:25:54 PM
>> Subject: Re: [PATCH] proto: add 'shift' extension.
>>
>> On 09/27/2016 01:15 PM, Paolo Bonzini wrote:
>>>> We could go in a different direction and export flag
>>>> 'has_zero_init' which will report that the storage is
>>>> initialized with all zeroes at the moment. In this
>>>> case mirroring code will not fall into this
>>>> branch.
>>> Why don't you add the zero_init flag to QEMU's NBD driver instead?
>> for all cases without knowing real backend on the server side?
>> I think this would be wrong.
> Add it to the command line, and leave it to libvirt or the user to
> pass "-drive file.driver=nbd,...,file.zero-init=on".
>
> Paolo
this specifically means that all QMP commands like 'drive-backup' and
'drive-mirror' will have to be modified to pass this attribute. If this is
OK, we can proceed with that.

Den