Re: [PATCH 4/6] iommu: Combine device strictness requests with the global default

[Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>]

On 6/22/21 7:52 AM, Douglas Anderson wrote:
> @@ -1519,7 +1542,8 @@ static int iommu_get_def_domain_type(struct device *dev)
>   
>   static int iommu_group_alloc_default_domain(struct bus_type *bus,
>   					    struct iommu_group *group,
> -					    unsigned int type)
> +					    unsigned int type,
> +					    struct device *dev)
>   {
>   	struct iommu_domain *dom;
>   
> @@ -1534,6 +1558,12 @@ static int iommu_group_alloc_default_domain(struct bus_type *bus,
>   	if (!dom)
>   		return -ENOMEM;
>   
> +	/* Save the strictness requests from the device */
> +	if (dev && type == IOMMU_DOMAIN_DMA) {
> +		dom->request_non_strict = dev->request_non_strict_iommu;
> +		dom->force_strict = dev->force_strict_iommu;
> +	}
> +

An iommu default domain might be used by multiple devices which might
have different "strict" attributions. Then who could override who?

Best regards,
baolu