Re: [PATCH for-4.19] docs/arm: Document where Xen should be loaded in memory

[Julien Grall <julien@xxxxxxx>]

On 24/10/2023 11:23, Michal Orzel wrote:
> Hi Julien,
Hi,

> On 24/10/2023 12:09, Julien Grall wrote:
> > From: Julien Grall <jgrall@xxxxxxxxxx>
> >
> > In commit 9d267c049d92 ("xen/arm64: Rework the memory layout"),
> > we decided to require Xen to be loaded below 5 TiB to simplify
> s/5/2
Ah yes. I keep having 2 TiB.

> > the logic to enable the MMU. The limit was decided based on
> > how known platform boot plus some slack.
> >
> > We had a recent report that this is not sufficient on the AVA
> > platform with a old firmware [1]. But the restriction is not
> > going to change in Xen 4.18. So document the limit clearly
> > in docs/misc/arm/booting.txt
> >
> > Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
> >
> > ----
> one less '-'
Yes. I forgot to call 'sed -i 's/^----/---/' *.patch' before sending (I 
use ---- to prevent my pacthqueue management tool to strip anything 
after ---).
> > I couldn't find a nice way to document it in SUPPORT.md. So I decided
> > to only document the restrict in docs/misc/arm/booting.txt for now.
> >
> > I also couldn't find any way from GRUB/UEFI (I didn't look much) to
> > specify the loading address.
> > ---
> >   docs/misc/arm/booting.txt | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/docs/misc/arm/booting.txt b/docs/misc/arm/booting.txt
> > index 02f7bb65ec6d..c6bdeafe5e5b 100644
> > --- a/docs/misc/arm/booting.txt
> > +++ b/docs/misc/arm/booting.txt
> > @@ -21,6 +21,10 @@ The exceptions to this on 32-bit ARM are as follows:
> >    zImage protocol should still be used and not the stricter "raw
> >    (non-zImage)" protocol described in arm/Booting.
> >
> > +The exceptions to this on 64-bit ARM are as follows:
> > +
> > + Xen binary should be loaded in memory below 2 TiB.
> > +
> >   There are no exception on 64-bit ARM.
> This sentence needs to be dropped then.
Whoops yes.

> With that:
> Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
Thanks!

Cheers,

--
Julien Grall