Re: [PATCH v2 4/6] iommu/vt-d: Add set_dev_pasid callback for nested domain

[Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>]

On 9/12/24 9:04 PM, Yi Liu wrote:
> @@ -4299,7 +4304,12 @@ domain_prepare_dev_pasid(struct iommu_domain *domain,
>   	unsigned long flags;
>   	int ret;
>   
> -	ret = prepare_domain_attach_device(domain, dev);
> +	/* Nested type domain should prepare its parent domain */
> +	if (domain_type_is_nested(dmar_domain))
> +		ret = prepare_domain_attach_device(
> +				&dmar_domain->s2_domain->domain, dev);
> +	else
> +		ret = prepare_domain_attach_device(domain, dev);
>   	if (ret)
>   		return ERR_PTR(ret);
>   

'prepare' is a bit confusing in this context. It actually means checking
whether a domain is compatible with the hardware capabilities of RID or
PASID. Or not?

I know this confusion comes from the naming of
prepare_domain_attach_device(). Hence, do you mind renaming this helper
in a small patch?

Thanks,
baolu