From c31a792a825a68ba59355c5a5af6f5801f716650 Mon Sep 17 00:00:00 2001
From: Tina Zhang <tina.zhang@intel.com>
Date: Wed, 16 Nov 2022 13:15:43 +0800
Subject: [PATCH] iommu/vt-d: Preset Access bit for IOVA in FL non-leaf paging
entries
commit 242b0aaeabbe2efbef1b9d42a8e56627e800964c upstream.
The A/D bits are preseted for IOVA over first level(FL) usage for both
kernel DMA (i.e, domain typs is IOMMU_DOMAIN_DMA) and user space DMA
usage (i.e., domain type is IOMMU_DOMAIN_UNMANAGED).
Presetting A bit in FL requires to preset the bit in every related paging
entries, including the non-leaf ones. Otherwise, hardware may treat this
as an error. For example, in a case of ECAP_REG.SMPWC==0, DMA faults might
occur with below DMAR fault messages (wrapped for line length) dumped.
DMAR: DRHD: handling fault status reg 2
DMAR: [DMA Read NO_PASID] Request device [aa:00.0] fault addr 0x10c3a6000
[fault reason 0x90]
SM: A/D bit update needed in first-level entry when set up in no snoop
Fixes: 289b3b005cb9 ("iommu/vt-d: Preset A/D bits for user space DMA usage")
Cc: stable@vger.kernel.org
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Link: https://lore.kernel.org/r/20221113010324.1094483-1-tina.zhang@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20221116051544.26540-2-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iommu/intel/iommu.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index b0a975e0a8cb0..fa0cf1c3775d9 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1048,11 +1048,9 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE);
pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE;
- if (domain_use_first_level(domain)) {
- pteval |= DMA_FL_PTE_XD | DMA_FL_PTE_US;
- if (iommu_is_dma_domain(&domain->domain))
- pteval |= DMA_FL_PTE_ACCESS;
- }
+ if (domain_use_first_level(domain))
+ pteval |= DMA_FL_PTE_XD | DMA_FL_PTE_US | DMA_FL_PTE_ACCESS;
+
if (cmpxchg64(&pte->val, 0ULL, pteval))
/* Someone else set it while we were thinking; use theirs. */
free_pgtable_page(tmp_page);
--
2.30.2