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xen/mmu: Set _PAGE_IOMAP if PFN is an identity PFN.

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If we find that the PFN is within the P2M as an identity
PFN make sure to tack on the _PAGE_IOMAP flag.

Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Konrad Rzeszutek Wilk 2011-01-05 15:46:31 -05:00
parent f4cec35b0d
commit fb38923ead
1 changed files with 16 additions and 2 deletions
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18
arch/x86/xen/mmu.c
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@ -416,8 +416,12 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
if (val & _PAGE_PRESENT) {
unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
pteval_t flags = val & PTE_FLAGS_MASK;
unsigned long mfn = pfn_to_mfn(pfn);
unsigned long mfn;
if (!xen_feature(XENFEAT_auto_translated_physmap))
mfn = get_phys_to_machine(pfn);
else
mfn = pfn;
/*
* If there's no mfn for the pfn, then just create an
* empty non-present pte. Unfortunately this loses
@ -427,8 +431,18 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
if (unlikely(mfn == INVALID_P2M_ENTRY)) {
mfn = 0;
flags = 0;
} else {
/*
* Paramount to do this test _after_ the
* INVALID_P2M_ENTRY as INVALID_P2M_ENTRY &
* IDENTITY_FRAME_BIT resolves to true.
*/
mfn &= ~FOREIGN_FRAME_BIT;
if (mfn & IDENTITY_FRAME_BIT) {
mfn &= ~IDENTITY_FRAME_BIT;
flags |= _PAGE_IOMAP;
}
}
val = ((pteval_t)mfn << PAGE_SHIFT) | flags;
}