Messages in this thread | | | Date | Tue, 21 Dec 2010 14:29:31 -0800 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 04/10] xen/mmu: For 1-1 mapping, automatically set _PAGE_IOMAP. |
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On 12/21/2010 01:37 PM, Konrad Rzeszutek Wilk wrote: > This means that for PFNs (specifically: those in any E820 gaps > or non-RAM E820 regions) that have 1-1 mapping we set the > _PAGE_IOMAP flag. > > Later on we could remove the _PAGE_IOMAP code handling, but > for right now lets keep this in to not introduce any bisection > failures across this patchset. > > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > arch/x86/xen/mmu.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c > index 4ba7e4e..bd02e7d 100644 > --- a/arch/x86/xen/mmu.c > +++ b/arch/x86/xen/mmu.c > @@ -832,6 +832,9 @@ static pteval_t pte_pfn_to_mfn(pteval_t val) > pteval_t flags = val & PTE_FLAGS_MASK; > unsigned long mfn = pfn_to_mfn(pfn); > > + if (mfn == pfn) > + flags |= _PAGE_IOMAP;
Why? Does it really make sense to set _PAGE_IOMAP if they just happen to be the same value?
J
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