From 423d39d8518c1bba12e0889a92beeddbb1502392 Mon Sep 17 00:00:00 2001 From: Liu Yi L Date: Wed, 18 Aug 2021 21:48:52 +0800 Subject: [PATCH] iommu/vt-d: Add present bit check in pasid entry setup helpers The helper functions should not modify the pasid entries which are still in use. Add a check against present bit. Signed-off-by: Liu Yi L Link: https://lore.kernel.org/r/20210817042425.1784279-1-yi.l.liu@intel.com Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20210818134852.1847070-10-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/pasid.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index 02e1049..b1d0c29 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -534,6 +534,10 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev, devtlb_invalidation_with_pasid(iommu, dev, pasid); } +/* + * This function flushes cache for a newly setup pasid table entry. + * Caller of it should not modify the in-use pasid table entries. + */ static void pasid_flush_caches(struct intel_iommu *iommu, struct pasid_entry *pte, u32 pasid, u16 did) @@ -585,6 +589,10 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu, if (WARN_ON(!pte)) return -EINVAL; + /* Caller must ensure PASID entry is not in use. */ + if (pasid_pte_is_present(pte)) + return -EBUSY; + pasid_clear_entry(pte); /* Setup the first level page table pointer: */ @@ -684,6 +692,10 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu, return -ENODEV; } + /* Caller must ensure PASID entry is not in use. */ + if (pasid_pte_is_present(pte)) + return -EBUSY; + pasid_clear_entry(pte); pasid_set_domain_id(pte, did); pasid_set_slptr(pte, pgd_val); @@ -723,6 +735,10 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu, return -ENODEV; } + /* Caller must ensure PASID entry is not in use. */ + if (pasid_pte_is_present(pte)) + return -EBUSY; + pasid_clear_entry(pte); pasid_set_domain_id(pte, did); pasid_set_address_width(pte, iommu->agaw); -- 2.7.4