| From e40b40b313a1b805635c064812237a4b142f4248 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Sat, 20 Mar 2021 10:54:12 +0800 |
| Subject: iommu/vt-d: Remove WO permissions on second-level paging entries |
| |
| From: Lu Baolu <baolu.lu@linux.intel.com> |
| |
| [ 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@intel.com> |
| Fixes: b802d070a52a1 ("iommu/vt-d: Use iova over first level") |
| Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> |
| Link: https://lore.kernel.org/r/20210320025415.641201-3-baolu.lu@linux.intel.com |
| Signed-off-by: Joerg Roedel <jroedel@suse.de> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/iommu/intel/iommu.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c |
| index 2f5d12cdb298..82300b0d3074 100644 |
| --- a/drivers/iommu/intel/iommu.c |
| +++ b/drivers/iommu/intel/iommu.c |
| @@ -2354,8 +2354,9 @@ __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; |
| -- |
| 2.30.2 |
| |
