Commit c1f46999ef506 ("amd_iommu: Add support for pass though mode")
introduces the support for "pt" flag by enabling nodma memory when
"pt=off". This allowed VFIO devices to successfully register notifiers
by using nodma region.
But, This also broke things when guest is booted with the iommu=nopt
because, devices bypass the IOMMU and use untranslated addresses (IOVA) to
perform DMA reads/writes to the nodma memory region, ultimately resulting in
a failure to setup the devices in the guest.
Fix the above issue by always enabling the amdvi_dev_as->iommu memory region.
But this will once again cause VFIO devices to fail while registering the
notifiers with AMD IOMMU memory region.
Fixes: c1f46999ef506 ("amd_iommu: Add support for pass though mode")
Signed-off-by: Sairaj Kodilkar <sarun...@amd.com>
Reviewed-by: Vasant Hegde <vasant.he...@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
