Re: [PATCH v3 4/4] pdx: Add CONFIG_PDX_COMPRESSION as a common Kconfig option

["Roger Pau Monné" <roger.pau@citrix.com>]

On Mon, Sep 25, 2023 at 08:36:03AM +0200, Jan Beulich wrote:
> On 22.09.2023 22:03, Andrew Cooper wrote:
> > On 08/08/2023 2:02 pm, Alejandro Vallejo wrote:
> >> --- a/xen/common/Kconfig
> >> +++ b/xen/common/Kconfig
> >> @@ -23,6 +23,16 @@ config GRANT_TABLE
> >>  
> >>  	  If unsure, say Y.
> >>  
> >> +config PDX_COMPRESSION
> >> +	bool "PDX (Page inDeX) compression support" if EXPERT
> > 
> > This still needs hiding on x86.  The minimal hack for 4.18 is "if EXPERT
> > && !X86".
> 
> If you insist on complete hiding and I insist on allowing it to be used by
> people who want to play with exotic hardware, then this won't go anywhere.
> I think I've come far enough with accepting a compromise, and so I think
> it's your turn now to also take a step from your original position.

Just because I'm not familiar with this, is there any x86 hardware
that has such sparse memory map that would benefit from PDX?

Wouldn't anyone doing bring up on such exotic hardware also likely need to
perform other adjustments to Xen, and hence commenting out the !X86 in
Kconfig be acceptable? (we would likely make it selectable at that
point if such platforms exist).

Thanks, Roger.