iommu/amd: Don't clear DTE flags when modifying it

During device assignment/deassignment the flags in the DTE
get lost, which might cause spurious faults, for example
when the device tries to access the system management range.
Fix this by not clearing the flags with the rest of the DTE.

Reported-by: G. Richard Bellamy <rbellamy@pteradigm.com>
Tested-by: G. Richard Bellamy <rbellamy@pteradigm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 08d2775887f7add00e44858cc6bf4a5eece6e260..532e2a211fe1cf9b3d7ff71d36cbcfde49bd29df 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1974,8 +1974,8 @@ static void set_dte_entry(u16 devid, struct protection_domain *domain, bool ats)
 static void clear_dte_entry(u16 devid)
 {
        /* remove entry from the device table seen by the hardware */
-       amd_iommu_dev_table[devid].data[0] = IOMMU_PTE_P | IOMMU_PTE_TV;
-       amd_iommu_dev_table[devid].data[1] = 0;
+       amd_iommu_dev_table[devid].data[0]  = IOMMU_PTE_P | IOMMU_PTE_TV;
+       amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
 
        amd_iommu_apply_erratum_63(devid);
 }

diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index f65908841be0184db61f049bc8e2b5a622ca2fbe..c9b64722f62309d76e56ad52c5a3691737ffd6ac 100644 (file)
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -295,6 +295,7 @@
 #define IOMMU_PTE_IR (1ULL << 61)
 #define IOMMU_PTE_IW (1ULL << 62)
 
+#define DTE_FLAG_MASK  (0x3ffULL << 32)
 #define DTE_FLAG_IOTLB (0x01UL << 32)
 #define DTE_FLAG_GV    (0x01ULL << 55)
 #define DTE_GLX_SHIFT  (56)