Re: [PATCH v8 06/13] iommu/amd: copy old trans table from old kernel

[Joerg Roedel]

On Fri, Jul 21, 2017 at 04:59:04PM +0800, Baoquan He wrote:
> @@ -2128,9 +2131,43 @@ static void early_enable_iommu(struct amd_iommu *iommu)
>  static void early_enable_iommus(void)
>  {
>  	struct amd_iommu *iommu;
> +	bool is_pre_enabled = false;
>  
> -	for_each_iommu(iommu)
> -		early_enable_iommu(iommu);
> +	for_each_iommu(iommu) {
> +		if (translation_pre_enabled(iommu)) {
> +			is_pre_enabled = true;
> +			break;
> +		}
> +	}

is_pre_enabled should only be true when _all_ iommus are pre-enabled. If
only one is found disabled just disable the others and continue without
copying the device table.