Commit fb38923e authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk
Browse files

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



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: default avatarIan Campbell <ian.campbell@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent f4cec35b

arch/x86/xen/mmu.c

+16 −2
Original line number Diff line number Diff line
@@ -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;

	}