On Thu, Jun 21, 2018 at 08:06:51PM +0100, Jean-Philippe Brucker wrote: > A virtio-mmio node may represent a virtio-iommu device. This is discovered > by the virtio driver at probe time, but the DMA topology isn't > discoverable and must be described by firmware. For DT the standard IOMMU > description is used, as specified in bindings/iommu/iommu.txt and > bindings/pci/pci-iommu.txt. Like many other IOMMUs, virtio-iommu > distinguishes masters by their endpoint IDs, which requires one IOMMU cell > in the "iommus" property. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.bruc...@arm.com> > --- > Documentation/devicetree/bindings/virtio/mmio.txt | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/Documentation/devicetree/bindings/virtio/mmio.txt > b/Documentation/devicetree/bindings/virtio/mmio.txt > index 5069c1b8e193..337da0e3a87f 100644 > --- a/Documentation/devicetree/bindings/virtio/mmio.txt > +++ b/Documentation/devicetree/bindings/virtio/mmio.txt > @@ -8,6 +8,14 @@ Required properties: > - reg: control registers base address and size including > configuration space > - interrupts: interrupt generated by the device > > +Required properties for virtio-iommu: > + > +- #iommu-cells: When the node describes a virtio-iommu device, it is > + linked to DMA masters using the "iommus" property as > + described in devicetree/bindings/iommu/iommu.txt. For > + virtio-iommu #iommu-cells must be 1, each cell describing > + a single endpoint ID.
The iommus property should also be documented for the client side. Rob _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
