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-paging-entries.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. >From eea53c5816889ee8b64544fa2e9311a81184ff9c Mon Sep 17 00:00:00 2001 From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx> commit eea53c5816889ee8b64544fa2e9311a81184ff9c upstream. 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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iommu/intel/iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2362,8 +2362,9 @@ static int __domain_mapping(struct dmar_ 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; Patches currently in stable-queue which might be from baolu.lu@xxxxxxxxxxxxxxx are queue-5.10/iommu-vt-d-remove-wo-permissions-on-second-level-paging-entries.patch queue-5.10/revert-iommu-vt-d-remove-wo-permissions-on-second-level.patch queue-5.10/revert-iommu-vt-d-preset-access-dirty-bits-for-iova.patch queue-5.10/iommu-vt-d-preset-access-dirty-bits-for-iova-over-fl.patch