Re: [PATCH] iommu/vt-d: Allocate reserved region for ISA with correct permission

From: Lu Baolu
Date: Sun Dec 15 2019 - 00:40:28 EST


Hi,

On 12/13/19 1:36 PM, Jerry Snitselaar wrote:
Currently the reserved region for ISA is allocated with no
permissions. If a dma domain is being used, mapping this region will
fail. Set the permissions to DMA_PTE_READ|DMA_PTE_WRITE.

Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx # v5.3+
Fixes: d850c2ee5fe2 ("iommu/vt-d: Expose ISA direct mapping region via iommu_get_resv_regions")
Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>

This fix looks reasonable to me.

Acked-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

Best regards,
baolu

---
drivers/iommu/intel-iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0c8d81f56a30..998529cebcf2 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5736,7 +5736,7 @@ static void intel_iommu_get_resv_regions(struct device *device,
struct pci_dev *pdev = to_pci_dev(device);
if ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA) {
- reg = iommu_alloc_resv_region(0, 1UL << 24, 0,
+ reg = iommu_alloc_resv_region(0, 1UL << 24, prot,
IOMMU_RESV_DIRECT);
if (reg)
list_add_tail(&reg->list, head);