vdpa: Skip protected ram IOMMU mappings

vdpa: Skip protected ram IOMMU mappings

Following the logic of commit 56918a126ae ("memory: Add RAM_PROTECTED
flag to skip IOMMU mappings") with VFIO, skip memory sections
inaccessible via normal mechanisms, including DMA.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20211014141236.923287-2-eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>