[PATCH 1/2] hw/i386/amd_iommu: Fix device setup failure when PT is on.

[Sairaj Kodilkar]

Current amd_iommu enables the iommu_nodma address space when pt_supported
flag is on. This causes device to bypass the IOMMU and use untranslated
address to perform DMA when guest kernel uses DMA mode, resulting in
failure to setup the devices in the guest.

Fix the issue by removing pt_supported check and disabling nodma memory
region. Adding pt_supported requires additional changes and we will look
into it later.

Fixes: c1f46999ef506 ("amd_iommu: Add support for pass though mode")
Signed-off-by: Sairaj Kodilkar <sarun...@amd.com>
---
 hw/i386/amd_iommu.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index 5f9b95279997..df8ba5d39ada 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -1426,7 +1426,6 @@ static AddressSpace *amdvi_host_dma_iommu(PCIBus *bus, 
void *opaque, int devfn)
     AMDVIState *s = opaque;
     AMDVIAddressSpace **iommu_as, *amdvi_dev_as;
     int bus_num = pci_bus_num(bus);
-    X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
 
     iommu_as = s->address_spaces[bus_num];
 
@@ -1486,15 +1485,8 @@ static AddressSpace *amdvi_host_dma_iommu(PCIBus *bus, 
void *opaque, int devfn)
                                             AMDVI_INT_ADDR_FIRST,
                                             &amdvi_dev_as->iommu_ir, 1);
 
-        if (!x86_iommu->pt_supported) {
-            memory_region_set_enabled(&amdvi_dev_as->iommu_nodma, false);
-            memory_region_set_enabled(MEMORY_REGION(&amdvi_dev_as->iommu),
-                                      true);
-        } else {
-            memory_region_set_enabled(MEMORY_REGION(&amdvi_dev_as->iommu),
-                                      false);
-            memory_region_set_enabled(&amdvi_dev_as->iommu_nodma, true);
-        }
+        memory_region_set_enabled(&amdvi_dev_as->iommu_nodma, false);
+        memory_region_set_enabled(MEMORY_REGION(&amdvi_dev_as->iommu), true);
     }
     return &iommu_as[devfn]->as;
 }
-- 
2.34.1