Re: [RFC] Design considerations for XSAVE Extended Area getters/setters

[Michał Górny <mgorny%NetBSD.org@localhost>]

On Tue, 2019-05-28 at 19:26 +0200, Kamil Rytarowski wrote:
> On 28.05.2019 18:34, Michał Górny wrote:
> > There is no difference in internal layout or logic between b. and c.
> > In either case, we need to perform XSAVE, process it and copy the data
> > into internal structure.  The only difference is that in b. we handle it
> > all in one request, and in c. we do three requests copying different
> > parts of XSAVE to three different buffers.
> > 
> 
> I see. So (b) and (c) are the same except that XSAVE is a struct of a
> dynamic size with normalized registers instead of explicit AVX, AVX512
> calls.
> 

The only real difference is the amount of work when adding new register
types.

With b., you just add a new field to the struct and some code to x86
that copies data to that field.

With c., you need to add the new PT_* request with all associated
functions.


-- 
Best regards,
Michał Górny