Re: [PATCH v2 06/19] iommufd/viommu: Add IOMMU_VIOMMU_SET/UNSET_VDEV_ID ioctl

Jason Gunthorpe
2024-09-05T17:44:47Z

On Thu, Sep 05, 2024 at 10:37:45AM -0700, Nicolin Chen wrote:

> we only have virtual device ID in its data structure. Also, the
> virtual device sounds a bit confusing, given we already have idev.

idev is "iommufd device" which is the physical device

The virtual device is the host side handle of a device in a VM.

> That being said, if we have a clear picture that in the long term
> we would extend it to hold more information, I think it could be
> a smart move.
>
> Perhaps virtual device can have its own "attach" to vIOMMU? Or
> would you still prefer attaching via proxy hwpt_nested?

I was thinking just creating it against a vIOMMU is an effective
"attach" and the virtual device is permanently tied to the vIOMMU at
creation time.

Is there more to attach?

I think some CC stuff had a few more verbs in the lifecycle though

Jason