This capability detects the availability of the virtio-iommu-pci
device.
Note that, while this device is present even in somewhat old
versions of QEMU, it's only some recent changes that made it
actually usable for our purposes.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
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