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Commit 6d568ef9 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/amd: Allow downgrading page-sizes in alloc_pte() 



Before this patch it was not possible the downgrade a
mapping established with page-mode 7 to a mapping using
smaller page-sizes, because the pte_level != level check
prevented that.

Treat page-mode 7 like a non-present mapping and allow to
overwrite it in alloc_pte().

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 69be8852

drivers/iommu/amd_iommu.c

+9 −3
Original line number Diff line number Diff line
@@ -1460,10 +1460,13 @@ static u64 *alloc_pte(struct protection_domain *domain, 


	while (level > end_lvl) {

		u64 __pte, __npte;

		int pte_level;



		__pte     = *pte;

		pte_level = PM_PTE_LEVEL(__pte);



		if (!IOMMU_PTE_PRESENT(__pte)) {

		if (!IOMMU_PTE_PRESENT(__pte) ||

		    pte_level == PAGE_MODE_7_LEVEL) {

			page = (u64 *)get_zeroed_page(gfp);

			if (!page)

				return NULL;
@@ -1475,10 +1478,13 @@ static u64 *alloc_pte(struct protection_domain *domain, 
				free_page((unsigned long)page);

				continue;

			}



			if (pte_level == PAGE_MODE_7_LEVEL)

				domain->updated = true;

		}



		/* No level skipping support yet */

		if (PM_PTE_LEVEL(*pte) != level)

		if (pte_level != level)

			return NULL;



		level -= 1;