Hi Eric,
On Fri, Feb 07, 2020 at 10:32:00AM +0100, Eric Auger wrote:
> At the moment, the kernel only supports device tree
> integration of the virtio-iommu. DT bindings between the
> PCI root complex and the IOMMU must be created by the machine
> in conformance to:
>
> Documentation/devicetree/bindings/virtio/iommu.txt.
>
> To make sure the end-user is aware of this, force him to use the
> temporary device option "x-dt-binding" and also double check the
> machine has a hotplug handler for the virtio-iommu-pci device.
> This hotplug handler is in charge of creating those DT bindings.
>
> Signed-off-by: Eric Auger <eric.au...@redhat.com>
> Suggested-by: Michael S. Tsirkin <m...@redhat.com>
[...]
> @@ -39,6 +42,21 @@ static void virtio_iommu_pci_realize(VirtIOPCIProxy
> *vpci_dev, Error **errp)
> VirtIOIOMMUPCI *dev = VIRTIO_IOMMU_PCI(vpci_dev);
> DeviceState *vdev = DEVICE(&dev->vdev);
>
> + if (!dev->dt_binding) {
> + error_setg(errp,
> + "Instantiation currently only is possible if the machine "
> + "creates device tree iommu-map bindings, ie. ACPI is not "
> + "yet supported");
> + error_append_hint(errp, "use -virtio-iommu-pci,x-dt-binding\n");
"use -device virtio-iommu-pci,x-dt-binding"?
Can the option be safely removed as soon as we implement a topology
description for the remaining platforms? Or will we need to carry it
forever for backward-compatibility (ie. ensure that an old command-line
invocation that contains this option still works)?
Thanks,
Jean
