> Subject: Re: UEFI support in ARM DomUs
>
>
> On 6/19/20 3:59 PM, Julien Grall wrote:
> > Hi,
> >
> > On 19/06/2020 13:51, Oleksandr Andrushchenko wrote:
> >> On 6/19/20 3:47 PM, Julien Grall wrote:
> >>> They will not be available from the fdt, but you can retrieve them with an
> hypervisor call (see HVM_PARAM_STORE_PFN,
> HVM_PARAM_CONSOLE_PFN).
> >> Yes, and it used in the relevant pieces of code (hyp calls)
> >>> One question though, why do you need to map them in advance?
> Couldn't you map them on demand?
> >>
> >> Well, we need to at least estimate the pg_table size so we can reserve and
> allocate memory later,
> >
> > Oh, so U-boot doesn't support runtime page-table table allocation. Is that
> right?
> As per my understanding no, we provide a memory map and the tables are
> allocated beforehand
You are right.
Regards,
Peng.
> >
> >>
> >> so I have to provide memory range from either by coding a constant or
> looking into the devtree at
> >>
> >> hypervisor { reg = <>; }. It is a bit tricky though
> >
> > Looking for a node in the device-tree shouldn't be too difficult given that
> > you
> have fdt_* available.
> >
> > However, please not that <reg> doesn't refer to the guest magic pages.
> Instead, it provides a region you can use for mapping the grant-table frames
>
> Indeed, this is in my case 0x38000000, but the magic is at 0x39000000
>
> So, I need the memory range set up beforehand, but I can't as there is no cute
> way to get that.
>
> Of course, I can issue a hyp call to get HVM_PARAM_CONSOLE_PFN and use it
> as the base address,
>
> but this smells like a hack. I can call other HVM_PARAM_ to get their pfns and
> set up the memory regions,
>
> but this looks a bit weird. I need that constant badly ;)
>
> >
> > Cheers,
> >
