On 25.09.2023 11:46, Roger Pau Monné wrote: > 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).
As mentioned before, the reason PDX was introduced was to actually make Xen work on such exotic x86 hardware. While I can't tell for sure, that hardware probably has never made it into production. Yet still things were known to work there after the original adjustments, so no, I would not expect other adjustments to be necessary (provided there was no bitrot). Jan
