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To:     John Garry <john.garry@huawei.com>, joro@8bytes.org,
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References: <1623414043-40745-1-git-send-email-john.garry@huawei.com>
 <1623414043-40745-4-git-send-email-john.garry@huawei.com>
From:   Lu Baolu <baolu.lu@linux.intel.com>
Subject: Re: [PATCH v12 3/5] iommu/vt-d: Add support for IOMMU default DMA
 mode build options
Message-ID: <4f2cec34-bad9-e1bf-85c1-04d1a0c1aecf@linux.intel.com>
Date:   Sat, 12 Jun 2021 10:22:05 +0800
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On 2021/6/11 20:20, John Garry wrote:
> @@ -453,8 +452,7 @@ static int __init intel_iommu_setup(char *str)
>   			pr_warn("intel_iommu=forcedac deprecated; use iommu.forcedac instead\n");
>   			iommu_dma_forcedac = true;
>   		} else if (!strncmp(str, "strict", 6)) {
> -			pr_info("Disable batched IOTLB flush\n");
> -			intel_iommu_strict = 1;
> +			iommu_set_dma_strict(true);

I would like to deprecate this command line and ask users to use
iommu.strict instead.

--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -436,7 +436,7 @@ static int __init intel_iommu_setup(char *str)
                         pr_warn("intel_iommu=forcedac deprecated; use 
iommu.forcedac instead\n");
                         iommu_dma_forcedac = true;
                 } else if (!strncmp(str, "strict", 6)) {
-                       pr_info("Disable batched IOTLB flush\n");
+                       pr_warn("intel_iommu=strict deprecated; use 
iommu.strict instead\n");
                         intel_iommu_strict = 1;

Also update Documentation/admin-guide/kernel-parameters.txt accordingly.

Best regards,
baolu