On Wed, 2 Feb 2022 20:54:38 +0100
Halil Pasic <pa...@linux.ibm.com> wrote:
> }
> @@ -82,9 +78,14 @@ void virtio_bus_device_plugged(VirtIODevice *vdev, Error
> **errp)
> return;
> }
>
> + vdev_has_iommu = virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
> if (klass->get_dma_as != NULL && has_iommu) {
> virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
> vdev->dma_as = klass->get_dma_as(qbus->parent);
> + if (!vdev_has_iommu && vdev->dma_as != &address_space_memory) {
> + error_setg(errp,
> + "iommu_platform=true is not supported by the device");
> + }
I'm wondering, would it be wise to change the message? Since this is now
dependent on the VM/bus the device is plugged into the message might be a
little misleading: i.e. the very same device could work perfectly fine
with iommu_platform=true if the "surroundings" are different.
Maybe "the device has no IOMMU support (iommu_platform=true)" would be a
better option. On the other hand changing the message has its downsides
as well.
Also I realized that keeping the return after error_setg() might have
been a good idea for the case more logic is added at the end of the
function.
In any case I would like to address these, if necessary with a separate
patch. I don't want the fix to experience any further delays.
Regards,
Halil
