Re: Making QEMU easier for management tools and applications

[John Snow]

On 1/24/20 1:52 PM, Dr. David Alan Gilbert wrote:
> * John Snow (address@hidden) wrote:
>>
>>
>> On 1/24/20 1:30 PM, Dr. David Alan Gilbert wrote:
>>> However, I caution that too many people think that QMP has all the type
>>> of diagnostic stuff people want - it's just way too hard and beuracratic
>>> to add a simple diagnostic command to QMP, when you just want to add
>>> something to print some diagnostics out for your corner of qemu.
>>
>> I'm not sure I follow, do you mean bureaucratic in contrast to... HMP?
> 
> I mean, someone who adds a QMP command is expected to be a lot more
> careful about the long term stability and proper structures etc etc.
> Where for HMP, if someone wants to add a command that's useful to the
> diagnostics of their part of QEMU and doesn't break anything else, then
> fine.
> 
> Dave

It sounds like we want a formalized notion of "x-debug-" for QMP
commands where we use feature flags to explicitly mark a command
interface as a debugging interface.

(We use such a command for bitmap iotests, to compute checksums of
bitmaps to ensure they migrate correctly. We make no guarantee that this
is stable or useful.)

I'm not sure if it's wise or not, but we could disable these commands
entirely unless you configure with --enable-qmp-debugging.

Might ease that pain of migrating everything onto QMP.

--js