Re: [RFC PATCH-for-8.0 2/3] hw/ppc/spapr: Replace tswap64(HPTE) by cpu_to_be64(HPTE)

[Cédric Le Goater]

On 12/21/22 13:33, Peter Maydell wrote:
> On Wed, 21 Dec 2022 at 01:35, David Gibson <david@gibson.dropbear.id.au> wrote:
> > On Mon, Dec 19, 2022 at 10:39:40AM +0000, Peter Maydell wrote:
> > > OK. I still think we should consistently change all the places that are
> > > accessing this data structure, though, not just half of them.
> >
> > Yes, that makes sense.  Although what exactly constitutes "this data
> > structure" is a bit complex here.  If we mean just the spapr specific
> > "external HPT", then there are only a few more references to it.  If
> > we mean all instances of a powerpc hashed page table, then there are a
> > bunch more in the cpu target code.
>
> I had in mind "places where we write this specific array of bytes
> spapr->htab".


spapr_store_hpte() seems to be the most annoying part. It is used
by hcalls h_enter, h_remove, h_protect. Reworking the interface
to present pte0/pte1 as BE variables means reworking the whole
hw/ppc/spapr_softmmu.c file. That's feasible but not a small task
since the changes will root down in the target hash mmu code which
is shared by all platforms ... :/

spapr_hpte_set_c() are spapr_hpte_set_r() are of a different kind.

C.