arm64: Add support for protected VMs

Introduce a new '--protected' parameter which requests the creation of
a protected VM type from the kernel. In addition, a reserved DMA region
is advertised in the device-tree and VIRTIO_F_ACCESS_PLATFORM is
advertised so that virtio transfers can be bounced through a shared
memory window.

Signed-off-by: Will Deacon <will@kernel.org>
6 files changed