From: Joerg Roedel <jroedel@xxxxxxx>
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: Joerg Roedel <jroedel@xxxxxxx>
---
drivers/iommu/amd_iommu.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 49b5d3115e56..6a88ba9321d1 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -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 = *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;
--
2.17.1
