Re: [Qemu-devel] [v1 Patch 1/10]Qemu: Enhance "info block" to display host cache setting

[Kevin Wolf]

Am 15.06.2012 23:07, schrieb Eric Blake:
> On 06/15/2012 02:47 PM, Supriya Kannery wrote:
>> Enhance "info block" to display hostcache setting for each
>> block device.
>>
> 
>>  ##
>>  { 'type': 'BlockInfo',
>>    'data': {'device': 'str', 'type': 'str', 'removable': 'bool',
>> -           'locked': 'bool', '*inserted': 'BlockDeviceInfo',
>> +           'locked': 'bool','hostcache': 'bool', '*inserted': 
>> 'BlockDeviceInfo',
> 
> space after comma
> 
> Since 'hostcache' was not present when talking to older qemu, should we
> mark it optional?

What does "optional" really mean? I always understood that it means that
whether the field exists or not depends on some runtime condition, not
on the qemu version. I would specify something like this, that always
exists in new qemu versions, in the "Since" section. Or maybe a separate
"Since" specification like in SpiceInfo for mouse-mode.

Kevin