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

commit cbf3ccd09d683abf1cacd36e3640872ee912d99b upstream.

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>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index dfb401cba73364c57121760fd1871570fa3d2da2..6bde2a124c72485e372f16f713ca93a4efb6cd0d 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2106,8 +2106,8 @@ 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 0285a215df162e18552d241ac753e0bd42c74600..7570f45fce8d5983e4c5ac5adf3cf8661bc4cbec 100644 (file)
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -282,6 +282,7 @@
 #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)