RE: [PATCH v4 04/12] iommu/vt-d: Add helper to setup pasid nested translation

[Tian, Kevin]

> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Thursday, August 3, 2023 11:13 AM
> 
> On 2023/8/2 15:10, Tian, Kevin wrote:
> >> From: Liu, Yi L<yi.l.liu@xxxxxxxxx>
> >> Sent: Monday, July 24, 2023 7:13 PM
> >> +
> >> +	if (!ecap_nest(iommu->ecap)) {
> >> +		pr_err_ratelimited("%s: No nested translation support\n",
> >> +				   iommu->name);
> >> +		return -ENODEV;
> >> +	}
> > -EINVAL
> 
> This is in the attach domain path. -EINVAL has the special meaning of
> "this domain is not compatible with iommu for the device".
> 
> So here, I still think we should return -ENODEV and the caller doesn't
> need to retry anymore.
> 

You are right. I overlooked that this validation is for a device cap.