Re: [v2 1/4] xen/arm64: head: Don't map too much in boot_third

[Julien Grall <julien@xxxxxxx>]

Hi Michal,

On 30/06/2023 07:50, Michal Orzel wrote:
> On 29/06/2023 22:11, Julien Grall wrote:
> > From: Julien Grall <jgrall@xxxxxxxxxx>
> >
> > At the moment, we are mapping the size of the reserved area for Xen
> > (i.e. 2MB) even if the binary is smaller. We don't exactly know what's
> > after Xen, so it is not a good idea to map more than necessary for a
> > couple of reasons:
> >      * We would need to use break-before-make if the extra PTE needs to
> >        be updated to point to another region
> >      * The extra area mapped may be mapped again by Xen with different
> >        memory attribute. This would result to attribute mismatch.
> >
> > Therefore, rework the logic in create_page_tables() to map only what's
> > necessary. To simplify the logic, we also want to make sure _end
> > is page-aligned. So align the symbol in the linker and add an assert
> > to catch any change.
> >
> > Lastly, take the opportunity to confirm that _start is equal to
> > XEN_VIRT_START as the assembly is using both interchangeably.
> >
> > Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
> NIT: it looks like other maintainers are not CCed on this series.
Whoops. I forgot to call scripts/add_maintainers.pl. I see that Bertrand 
reviewed it. So I will not resend it.
> Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
Thanks!

Cheers,

--
Julien Grall