RE: [PATCH 1/1] iommu/vt-d: Add set_dev_pasid callbacks for default domain

From: Tian, Kevin
Date: Tue Jun 14 2022 - 01:37:10 EST


> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Tuesday, June 14, 2022 12:48 PM
>
> On 2022/6/14 12:02, Tian, Kevin wrote:
> >> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> >> Sent: Tuesday, June 14, 2022 11:44 AM
> >>
> >> This allows the upper layers to set a domain to a PASID of a device
> >> if the PASID feature is supported by the IOMMU hardware. The typical
> >> use cases are, for example, kernel DMA with PASID and hardware
> >> assisted mediated device drivers.
> >>
> >
> > why is it not part of the series for those use cases? There is no consumer
> > of added callbacks in this patch...
>
> It could be. I just wanted to maintain the integrity of Intel IOMMU
> driver implementation.

but let's not add dead code. and this patch is actually a right step
simply from set_dev_pasid() p.o.v hence you should include in any
series which first tries to use that interface.

>
> >
> >> +/* PCI domain-subdevice relationship */
> >> +struct subdev_domain_info {
> >> + struct list_head link_domain; /* link to domain siblings */
> >> + struct device *dev; /* physical device derived from */
> >> + ioasid_t pasid; /* PASID on physical device */
> >> +};
> >> +
> >
> > It's not subdev. Just dev+pasid in iommu's context.
>
> How about struct device_pasid_info?
>

this is better.