Re: [PATCH v13 4/6] iommu/vt-d: Add support for IOMMU default DMA mode build options

[Lu Baolu]

On 6/16/21 7:03 PM, John Garry wrote:
> @@ -4382,9 +4380,9 @@ int __init intel_iommu_init(void)
>   		 * is likely to be much lower than the overhead of synchronizing
>   		 * the virtual and physical IOMMU page-tables.
>   		 */
> -		if (!intel_iommu_strict && cap_caching_mode(iommu->cap)) {
> -			pr_warn("IOMMU batching is disabled due to virtualization");
> -			intel_iommu_strict = 1;
> +		if (cap_caching_mode(iommu->cap)) {
> +			pr_warn("IOMMU batching disallowed due to virtualization\n");
> +			iommu_set_dma_strict(true);

With this change, VM guest will always show this warning. How about
removing this message? Users could get the same information through the
kernel message added by "[PATCH v13 2/6] iommu: Print strict or lazy
mode at init time".

Best regards,
baolu