Re: [PATCH RFCv1 00/14] Add Tegra241 (Grace) CMDQV Support (part 2/2)

Jason Gunthorpe
2024-05-22T16:48:25Z

On Wed, May 22, 2024 at 08:40:00AM +0000, Tian, Kevin wrote:
> > From: Nicolin Chen <nicolinc@nvidia.com>
> > Sent: Saturday, April 13, 2024 11:47 AM
> >
> > This is an experimental RFC series for VIOMMU infrastructure, using NVIDIA
> > Tegra241 (Grace) CMDQV as a test instance.
> >
> > VIOMMU obj is used to represent a virtual interface (iommu) backed by an
> > underlying IOMMU's HW-accelerated feature for virtualizaion: for example,
> > NVIDIA's VINTF (v-interface for CMDQV) and AMD"s vIOMMU.
> >
> > VQUEUE obj is used to represent a virtual command queue (buffer) backed
> > by
> > an underlying IOMMU command queue to passthrough for VMs to use
> > directly:
> > for example, NVIDIA's Virtual Command Queue and AMD's Command Buffer.
> >
>
> is VCMDQ more accurate? AMD also supports fault queue passthrough
> then VQUEUE sounds broader than a cmd queue...

Is there a reason VQUEUE couldn't handle the fault/etc queues too? The
only difference is direction, there is still a doorbell/etc.

Jason