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

[Paolo Bonzini]

----- 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