iommu/amd: Put IOMMUv2 capable devices in pt_domain

If the device starts to use IOMMUv2 features the dma handles
need to stay valid. The only sane way to do this is to use a
identity mapping for the device and not translate it by the
iommu. This is implemented with this patch. Since this lifts
the device-isolation there is also a new kernel parameter
which allows to disable that feature.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index d1e5067852d..7c3fd572a23 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -146,6 +146,8 @@ u32 amd_iommu_max_pasids __read_mostly = ~0;
 
 bool amd_iommu_v2_present __read_mostly;
 
+bool amd_iommu_force_isolation __read_mostly;
+
 /*
  * The ACPI table parsing functions set this variable on an error
  */
@@ -1642,6 +1644,8 @@ static int __init parse_amd_iommu_options(char *str)
                         amd_iommu_unmap_flush = true;
                 if (strncmp(str, "off", 3) == 0)
                         amd_iommu_disabled = true;
+                if (strncmp(str, "force_isolation", 15) == 0)
+                        amd_iommu_force_isolation = true;
         }
 
         return 1;