Re: [PATCH v2 1/4] xl: Add support for ignore_msrs option

[Julien Grall <julien@xxxxxxx>]

On 22/01/2021 18:39, Boris Ostrovsky wrote:
> On 1/22/21 1:33 PM, Julien Grall wrote:
>
> > Thanks. In which case, I would suggest to move the definition of ignore_msrs in the idle 
> > to an x86 specific structure. Maybe "arch_x86"?
>
> I did consider this but left it in common area since there are already a bunch 
> of fields there that are x86-specific.
Most of them were introduced before Arm existed :).

> If there is desire to create an x86 sub-struct then we should move all of them 
> there.
The libxl interface is meant to be stable at the source level but not 
ABI stable. So we wouldn't be able to move the existing field in a new 
x86 without adding a compat layer (see for instance hvm.altp2m vs 
altp2m). I don't think this is worth it for them.
That said, we should try to treat each architecture equally. So I think 
it is not a good idea to continue to pursue adding an field in common 
area if the field is only meant to be used for a single arch.
If Ian or Wei thinks it is fine to define in common code, then so it be.

Cheers,

--
Julien Grall