Please also refer to the wiki page for general scenarios of VT-d
emulation in QEMU: https://wiki.qemu.org/Features/VT-d.
+``-device virtio-iommu-pci[,option=...]``
+ This is only supported by ``-machine q35`` (x86_64) and ``-machine virt`` (ARM).
+ It supports below options:
+
+ ``granule=val`` (possible values are 4k, 8k, 16k, 64k and host; default: host)
+ This decides the default granule to be be exposed by the
+ virtio-iommu. If host, the granule matches the host page size.
+
ERST
DEF("name", HAS_ARG, QEMU_OPTION_name,