In nested mode, the stage 1 translation tables are owned by the guest and there is no caching on host side. So there is no need to replay the mappings.
As of today, the SMMUv3 nested mode is not yet implemented and there is no functional VFIO integration without. But keeping the replay call would execute the default implementation of memory_region_iommu_replay and attempt to translate the whole address range, completely stalling qemu. Keeping the MAP/UNMAP notifier registration allows to hit a warning message in the SMMUv3 device that tells the user which VFIO device will not function properly: "qemu-system-aarch64: -device vfio-pci,host=0000:89:00.0: warning: SMMUv3 does not support notification on MAP: device vfio-pci will not function properly" Besides, removing the replay call now allows the guest to boot. Signed-off-by: Eric Auger <eric.au...@redhat.com> --- hw/vfio/common.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index a859298fda..9ea58df67a 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -604,6 +604,7 @@ static void vfio_listener_region_add(MemoryListener *listener, if (memory_region_is_iommu(section->mr)) { VFIOGuestIOMMU *giommu; IOMMUMemoryRegion *iommu_mr = IOMMU_MEMORY_REGION(section->mr); + bool nested = false; int iommu_idx; trace_vfio_listener_region_add_iommu(iova, end); @@ -631,8 +632,12 @@ static void vfio_listener_region_add(MemoryListener *listener, QLIST_INSERT_HEAD(&container->giommu_list, giommu, giommu_next); memory_region_register_iommu_notifier(section->mr, &giommu->n); - memory_region_iommu_replay(giommu->iommu, &giommu->n); + memory_region_iommu_get_attr(iommu_mr, IOMMU_ATTR_VFIO_NESTED, + (void *)&nested); + if (!nested) { + memory_region_iommu_replay(iommu_mr, &giommu->n); + } return; } -- 2.20.1