Re: [PATCH v4 2/3] target/i386/cpu: Restrict some of feature-words uses to system-mode

[Philippe Mathieu-Daudé]

On 10/1/20 5:37 PM, Eduardo Habkost wrote:
> On Thu, Oct 01, 2020 at 05:27:32PM +0200, Philippe Mathieu-Daudé wrote:
>> On 10/1/20 5:14 PM, Paolo Bonzini wrote:
>>> On 01/10/20 16:41, Philippe Mathieu-Daudé wrote:
>>>> The feature-words properties are not used in user-mode emulation,
>>>> restrict it to system-mode.
>>>>
>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>>
>>> This seems a bit pointless honestly.  It's going to be a few KBs of code
>>> at most.  I would end the work with the patches that have already been
>>> queued.
>>
>> I'll let Eduardo and you discuss that, as he suggested the #ifdef
>> instead of the stub. The two options are on the list, whichever
>> you guys prefer :)
> 
> Having neither the stub or the #ifdef is even better.  :)
> 
> I assumed the stub was necessary as a means for an end, but now I
> don't understand why the stub was necessary in the first place.

x86_cpu_get_feature_words() calls QAPI-generated
visit_type_X86CPUFeatureWordInfoList().

Since "Only qemu-system-FOO and qemu-storage-daemon provide QMP
monitors", this code is unreachable on user-mode.

I tried to get a "no ifdef/no stub" codebase by not removing the
QAPI uses from user-mode code, and build it without QAPI-generated
files. I could only start the work and realized it is a huge effort.
In particular since nobody sees the point of doing this cleanup...

Regards,

Phil.