Re: [Qemu-devel] [RFC][PATCH 0/6] "bootonceindex" property

[Markus Armbruster <armbru@redhat.com>]

Eric Blake <eblake@redhat.com> writes:

> On 03/16/2017 04:46 AM, Janne Huttunen wrote:
>> On Wed, 2017-03-15 at 08:24 +0100, Gerd Hoffmann wrote:
>>>>
>>>> The short answer: emulating real hardware.
>>>
>>> Ok, that is reason enough.
>>>
>>> Adding bootonceindex everywhere doesn't look like the best plan to me
>>> though.  Possibly we can pimp up bootindex in a backward-compatible
>>> way?
>>> Something like bootindex=<normal>[.<once>] ?
>> 
>> That would (likely) avoid modifying all devices, but wouldn't
>> that make the 'bootindex' property a string (now: 'int32')
>> and thus change the QOM API?
>
> Is there any way to make use of an alternate that supports both int and
> string simultaneously?  But see also Markus' recent addendum on the
> difficulties of supporting multiple types on command-line vs. through QMP:
>
> https://lists.gnu.org/archive/html/qemu-devel/2017-03/msg04125.html

Making it a string that encodes two integers would be inappropriate for
QMP.  If you need two integers, QMP wants you to put two integers in
JSON.  That means either a new member next to bootindex, or turning
bootindex into an alternate of integer and object.

Not passing judgement on whether we actually need "once".