Re: [PATCH] Support Intel USER_MSR

[Jan Beulich <jbeulich@suse.com>]

On 24.10.2023 12:01, Hu, Lin1 wrote:
>> -----Original Message-----
>> From: Jan Beulich <jbeulich@suse.com>
>> Sent: Tuesday, October 24, 2023 4:56 PM
>>
>> On 24.10.2023 10:38, Hu, Lin1 wrote:
>>> I've thought of it so far is I can use a Fixup function like
>>>
>>> static bool
>>> uwrmsr_Fixup (instr_info *ins, int bytemode, int sizeflag) {
>>>     if (bytemode == d_mode)
>>>       {
>>>         if (OP_Skip_MODRM (ins, 0, sizeflag))
>>>           {
>>>             if (OP_I (ins, bytemode, sizeflag))
>>>               {
>>>                 ins->codep--;
>>>               }
>>>               return true;
>>>           }
>>>       }
>>>     return false;
>>> }
>>>
>>> Then the uwrmsr's unit will be { "uwrmsr",       {	{ uwrmsr_Fixup, d_mode },
>> Rq }, 0 }.
>>> What‘s your opinion?
>>
>> Hmm, not very nice, but I can't exclude it simply won't get any better.
>> My desire was for there to not be any new fixup function, and for
>> OP_Skip_MODRM to be used directly in the table entry. (In any event, if you
>> really need to keep this new function, please combine the three if()-s into a
>> single one, helping readability quite a bit.
>>
> 
> I have another idea, can I have a new function like
> 
> OP_back_codep(...)
> {
> 	Ins->codep--;
> 	Return true;
> }
> 
> So the uwrmsr's unit will be { "uwrmsr", { Skip_MODRM, Id, Back_Codep, Rq }, 0 }.

Well, the main thing I dislike is the decrementing of codep, no matter where
it's put. In case you don't think you can get away without, I guess I'll try
afterwards, aiming at an incremental change then.

Jan