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

Nicolin Chen
2025-07-01T22:38:00Z

On Tue, Jul 01, 2025 at 08:43:30PM +0000, Pranjal Shrivastava wrote:
> On Tue, Jul 01, 2025 at 01:23:17PM -0700, Nicolin Chen wrote:
> > Or perhaps calling them "non-accelerated commands" would be nicer.
>
> Uhh okay, so there'll be a separate driver in the VM issuing invalidation
> commands directly to the CMDQV thus we don't see any of it's part here?

That's how it works. VM must run a guest-level VCMDQ driver that
separates accelerated and non-accelerated commands as it already
does:

accelerated commands => VCMDQ (HW)
non-accelerated commands => SMMU CMDQ (SW) =iommufd=> SMMU CMDQ (HW)

Nicolin