Re: [PATCH] iommu/vt-d: Check for non-NULL domain on device release

[Baolu Lu]

On 2024/2/21 23:40, Jason Gunthorpe wrote:
> On Wed, Jan 31, 2024 at 03:10:53PM +0800, Baolu Lu wrote:
> > I like this suggestion.
> >
> > Currently, the device_release callback for an iommu driver does the
> > following:
> >
> > a) Silent IOMMU DMA translation. This is done by detaching the existing
> >     domain from the IOMMU and bringing the IOMMU into a blocking state
> >     (some drivers might be in identity state);
> > b) Releases the resources allocated in the probe callback and restores
> >     the device to its previous state before the probe.
> >
> >  From my understanding of your suggestion, we should move a) out of the
> > release callback and make it a special domain, which could be a blocking
> > domain or identity domain, depending on the iommu hardware.
> >
> > In the end, the release_device callback of an iommu driver should focus
> > on the opposite operation of device_probe. This makes the concept
> > clearer.
> Right
>
> Can someone make some patches to fix Eric's bug? We don't really need
> to do the release_domain stuff if the driver just self-attaches one of
> its known static domain types (blocking/identity)

I will follow up with a formal patch series.

Best regards,
baolu