summaryrefslogtreecommitdiffstats
path: root/drivers/iommu
diff options
context:
space:
mode:
authorAndrei Dulea <adulea@amazon.de>2019-09-13 16:42:29 +0200
committerJoerg Roedel <jroedel@suse.de>2019-09-24 11:15:37 +0200
commit6ccb72f8374e17d60b58a7bfd5570496332c54e2 (patch)
tree58153196ad6c1423e86fa4388cd402bb13fe384f /drivers/iommu
parent34c0989c05314b0288b058a4d1f6e58e2d320929 (diff)
downloadblackbird-op-linux-6ccb72f8374e17d60b58a7bfd5570496332c54e2.tar.gz
blackbird-op-linux-6ccb72f8374e17d60b58a7bfd5570496332c54e2.zip
iommu/amd: Fix downgrading default page-sizes in alloc_pte()
Downgrading an existing large mapping to a mapping using smaller page-sizes works only for the mappings created with page-mode 7 (i.e. non-default page size). Treat large mappings created with page-mode 0 (i.e. default page size) like a non-present mapping and allow to overwrite it in alloc_pte(). While around, make sure that we flush the TLB only if we change an existing mapping, otherwise we might end up acting on garbage PTEs. Fixes: 6d568ef9a622 ("iommu/amd: Allow downgrading page-sizes in alloc_pte()") Signed-off-by: Andrei Dulea <adulea@amazon.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/amd_iommu.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 138547446345..c7e28a8d25d1 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1490,6 +1490,7 @@ static u64 *alloc_pte(struct protection_domain *domain,
pte_level = PM_PTE_LEVEL(__pte);
if (!IOMMU_PTE_PRESENT(__pte) ||
+ pte_level == PAGE_MODE_NONE ||
pte_level == PAGE_MODE_7_LEVEL) {
page = (u64 *)get_zeroed_page(gfp);
if (!page)
@@ -1500,7 +1501,7 @@ static u64 *alloc_pte(struct protection_domain *domain,
/* pte could have been changed somewhere. */
if (cmpxchg64(pte, __pte, __npte) != __pte)
free_page((unsigned long)page);
- else if (pte_level == PAGE_MODE_7_LEVEL)
+ else if (IOMMU_PTE_PRESENT(__pte))
domain->updated = true;
continue;
OpenPOWER on IntegriCloud