[Skiboot] [RFC PATCH v3 2/6] Add ultravisor support in OPAL

[Oliver O'Halloran]

On Thu, Feb 27, 2020 at 11:19 PM Ryan Grimm <grimm at linux.vnet.ibm.com> wrote:
>
> > >             /*
> > >              * Workaround broken HDAT reserve regions which are
> > > -            * bigger than 512MB
> > > +            * bigger than 512MB and not secure memory
> > >              */
> > > -           if ((end_addr - start_addr) > 0x20000000) {
> > > +           if (((end_addr - start_addr) > 0x20000000) &&
> > > +                   !(start_addr & UV_SECURE_MEM_BIT)) {
> > >                     prlog(PR_ERR, "MEM: Ignoring Bad HDAT reserve:
> > > too big\n");
> > >                     continue;
> > >             }
> >
> > I think you can drop this hunk since secure memory isn't in the
> > reserved memory ranges any more. The definition of UV_SECURE_MEM_BIT
> > in
> > hdata/memory.c can go too since it's only used here.
> >
>
> I talk about this in the doc:
>
> Regions of secure memory will be reserved by hostboot such as OCC,
> HOMER, and SBE. Skiboot will use the existing reserve infrastructure to
> reserve them. For example:
>
> ibm,HCODE at 100fffcaf0000
> ibm,OCC at 100fffcdd0000
> ibm,RINGOVD at 100fffcae0000
>
> So we need to not ignore those reserves.  If the code is awkard, I can
> fix but we need it.

We get passed the same set of reservations today and they're
definitely not bigger than 512MB. Are they really that large when
placed in secure memory?