Re: [PATCH v3 4/5] iommu: Introduce iommu_dev_reset_prepare() and iommu_dev_reset_done()

Nicolin Chen
2025-08-15T20:11:12Z

On Fri, Aug 15, 2025 at 01:49:55PM +0800, Baolu Lu wrote:
> On 8/12/25 06:59, Nicolin Chen wrote:
> > Provide a callback from the PCI subsystem that will enclose the reset and
> > have the iommu core temporarily change all the attached domain to BLOCKED.
> > After attaching a BLOCKED domain, IOMMU drivers should fence any incoming
>
> Nit, my understanding is that it's not the "IOMMU drivers" but the
> "IOMMU hardware" that fences any further incoming translation requests,
> right?

Yes. I will change this to:

Provide a callback from the PCI subsystem that will enclose the reset and
have the iommu core temporarily change all the attached domain to BLOCKED.
After attaching a BLOCKED domain, IOMMU hardware would fence any incoming
ATS queries. And IOMMU drivers should also synchronously stop issuing new
ATS invalidations and wait for all ATS invalidations to complete. This can
avoid any ATS invaliation timeouts.

Thanks
Nicolin