Re: [PATCH -v2] EFI: Runtime services virtual mapping

Dave Young
2013-09-23T07:09:06Z

On 09/23/13 at 08:29am, Borislav Petkov wrote:
> On Mon, Sep 23, 2013 at 01:47:41PM +0800, Dave Young wrote:
> > > + unsigned long size = md->num_pages << PAGE_SHIFT;
> > > +
> > > + efi_va -= size;
> > > + if (efi_va < EFI_VA_END) {
> > > + pr_warning(FW_WARN "VA address range overflow!\n");
> > > + return;
> > > + }
> > > +
> > > + /* Do the 1:1 map */
> > > + __map_region(md, md->phys_addr);
> > > +
> > > + /* Do the VA map */
> > > + __map_region(md, efi_va);
> >
> >
> > Could you add comment for above code? It's hard to understand the
> > twice mapping if one did not follow the old thread.
>
> Does that suffice:
>
> /*
> * Make sure the 1:1 mappings are present as a catch-all for b0rked firmware
> * which doesn't update all internal pointers after switching to virtual mode
> * and would otherwise crap on us.
> */
>
> ?

Yes, looks good. Thanks

>
> Btw, when you reply to a mail, please remove that quoted portion of it
> which you're not replying to - I had to scroll a bunch of screens down
> and I almost missed your reply. :)

Will do. I did notice the problem after I enter 'y' in mutt, sorry about it.

>
> Thanks.
>
> --
> Regards/Gruss,
> Boris.
>
> Sent from a fat crate under my desk. Formatting is fine.
> --