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>
This commit is contained in:
Joerg Roedel 2015-10-20 14:59:36 +02:00
parent d14f6fced5
commit cbf3ccd09d
2 changed files with 3 additions and 2 deletions

View file

@ -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);
}

View file

@ -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)