Re: [PATCH] x86/efi: Always map boot service regions into new EFI page tables

[Matt Fleming]

On Mon, 14 Mar, at 11:30:19AM, Ingo Molnar wrote:
> 
> * Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> wrote:
> 
> > diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
> > index 8fee5b6f8f66..af74849e8c0f 100644
> > --- a/arch/x86/mm/pageattr.c
> > +++ b/arch/x86/mm/pageattr.c
> > @@ -1055,7 +1055,7 @@ static int populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd,
> >  	/*
> >  	 * Map everything starting from the Gb boundary, possibly with 1G pages
> >  	 */
> > -	while (end - start >= PUD_SIZE) {
> > +	while (cpu_has_gbpages && end - start >= PUD_SIZE) {
> >  		set_pud(pud, __pud(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
> >  				   massage_pgprot(pud_pgprot)));
> 
> Btw., can 'cpa->pfn << PAGE_SHIFT' possibly work on 32-bit systems?
> 
> cpa->pfn is unsigned long, so the result gets truncated to 32 bits ...
> 
> cpa->pfn should be u64.

That is a nice catch.

Note that we never run this code on 32-bit right now. Moving 32-bit to
this code and away from the old_map scheme is on my TODO list.