Re: [PATCH v7 27/28] iommu/tegra241-cmdqv: Add user-space use support

Pranjal Shrivastava
2025-07-10T10:54:22Z

On Fri, Jul 04, 2025 at 09:50:12AM -0300, Jason Gunthorpe wrote:
> On Thu, Jul 03, 2025 at 06:48:42PM +0000, Pranjal Shrivastava wrote:
>
> > Ahh, thanks for this, that saved a lot of my time! And yes, I see some
> > functions in eventq.c calling the iopf_group_response which settles the
> > CMD_RESUME. So.. I assume these resume commands would be trapped and
> > *actually* executed through this or a similar path for vPRI.
>
> Yes, that is what Intel did. PRI has to be tracked in the kernel
> because we have to ack requests eventually. If the VMM crashes the
> kernel has to ack everything and try to clean up.
>

I see.. thanks for clarifying!

> Also SMMUv3 does not support PRI today, just stall.
>

Ack. Thanks!

> Jason
Praan