To match the dma-ops api path the DMA_PTE_READ should be set if ZLR
isn't supported in the iommu

Signed-off-by: Tom Murphy <tmur...@arista.com>
---
 drivers/iommu/intel-iommu.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 980fc4816d72..e78b0000056d 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4378,6 +4378,17 @@ static void intel_iommu_detach_device(struct 
iommu_domain *domain,
        dmar_remove_one_dev_info(dev);
 }
 
+static bool supports_zlr(struct dmar_domain *domain)
+{
+       int i;
+
+       for_each_domain_iommu(i, domain) {
+               if (cap_zlr(g_iommus[i]->cap))
+                       return true;
+       }
+       return false;
+}
+
 static int intel_iommu_map(struct iommu_domain *domain,
                           unsigned long iova, phys_addr_t hpa,
                           size_t size, int iommu_prot)
@@ -4391,7 +4402,7 @@ static int intel_iommu_map(struct iommu_domain *domain,
        if (dmar_domain == si_domain && hw_pass_through)
                return 0;
 
-       if (iommu_prot & IOMMU_READ)
+       if (iommu_prot & IOMMU_READ || !supports_zlr(dmar_domain))
                prot |= DMA_PTE_READ;
        if (iommu_prot & IOMMU_WRITE)
                prot |= DMA_PTE_WRITE;
-- 
2.17.1

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