This is a note to let you know that I've just added the patch titled
iommu/vt-d: Remove WO permissions on second-level paging entries
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-vt-d-remove-wo-permissions-on-second-level-pag.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1fad6b33a2e1cbbc74e40974d9c9cc6d3e66f4d3
Author: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Date: Sat Mar 20 10:54:12 2021 +0800
iommu/vt-d: Remove WO permissions on second-level paging entries
[ Upstream commit eea53c5816889ee8b64544fa2e9311a81184ff9c ]
When the first level page table is used for IOVA translation, it only
supports Read-Only and Read-Write permissions. The Write-Only permission
is not supported as the PRESENT bit (implying Read permission) should
always set. When using second level, we still give separate permissions
that allows WriteOnly which seems inconsistent and awkward. We want to
have consistent behavior. After moving to 1st level, we don't want things
to work sometimes, and break if we use 2nd level for the same mappings.
Hence remove this configuration.
Suggested-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Fixes: b802d070a52a1 ("iommu/vt-d: Use iova over first level")
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210320025415.641201-3-baolu.lu@xxxxxxxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 8010c3895f8c..30c2b52f7ea2 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2357,8 +2357,9 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
return -EINVAL;
attr = prot & (DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP);
+ attr |= DMA_FL_PTE_PRESENT;
if (domain_use_first_level(domain)) {
- attr |= DMA_FL_PTE_PRESENT | DMA_FL_PTE_XD | DMA_FL_PTE_US;
+ attr |= DMA_FL_PTE_XD | DMA_FL_PTE_US;
if (domain->domain.type == IOMMU_DOMAIN_DMA) {
attr |= DMA_FL_PTE_ACCESS;
