Re: [PATCH v12 3/5] iommu/vt-d: Add support for IOMMU default DMA mode build options

From: John Garry
Date: Mon Jun 14 2021 - 10:26:05 EST


On 14/06/2021 15:11, Robin Murphy wrote:
On 2021-06-14 08:53, John Garry wrote:
On 12/06/2021 03:22, Lu Baolu wrote:
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.
ok, but then I should probably make the AMD driver also officially
support this.
Oops, I should have documented that "iommu.strict" already applies to
x86 as well. The interaction with the driver-specific parameters is a
bit weird and unintuitive, but it was done knowingly. Let me quickly
spin a kernel-parameters.txt fix for that...

So I already had a pending patch here for the same to be included in this series:
https://github.com/hisilicon/kernel-dev/commit/2375a2d888d78de9eb7d91d6f2c5891395300a96

If you want to do it, then ok. I might have to reorder the series though...

Thanks,
John