Re: [PATCH 4/4] x86, efi: Map runtime services 1:1

From: Borislav Petkov
Date: Mon Jun 10 2013 - 08:55:40 EST

On Thu, Jun 06, 2013 at 12:38:10PM -0700, H. Peter Anvin wrote:
> On 06/06/2013 12:36 PM, Borislav Petkov wrote:
> > On Thu, Jun 06, 2013 at 12:28:20PM -0700, H. Peter Anvin wrote:
> >> Or we could materialize mappings for this specific PGD. However,
> >> adding a read of %cr3 in __do_page_fault sounds expensive.
> >
> > Yes, I think we want to make sure all mappings are there when we do an
> > EFI runtime call so that we never #PF while it executes.
> >
> > Matt mentioned on IRC that the it could be that his EFI runtime is
> > referencing EFI_RESERVED area which we don't map. However, we need to
> > confirm/disprove that first, as it is currently only a hunch.


booting the patchset on my Dell looks good here. Booting at least, I
don't know about other stuff. If you have an EFI test suite or want me
to try stuff out, let me know. efibootmgr output looks sane too.

Btw, I've added a printk to the code so that we know that we've managed
switching to the 1:1 thing:

[ 0.073119] efi: Using 1:1 map.



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