Re: [PATCH v2 3/8] iommu/amd: Add debugfs support to dump IOMMU Capability registers

From: Srivastava, Dheeraj Kumar
Date: Tue Jan 07 2025 - 01:03:44 EST


Hi,

On 11/27/2024 2:29 AM, Bjorn Helgaas wrote:
On Wed, Nov 06, 2024 at 01:16:34PM +0530, Dheeraj Kumar Srivastava wrote:
IOMMU Capability registers defines capabilities of IOMMU and information
needed for initialising MMIO registers and device table. This is useful
to dump these registers for debugging IOMMU related issues.

e.g.To get capability registers value for iommu<x>
# echo "0x10" > /sys/kernel/debug/iommu/amd/iommu00/capability
# cat /sys/kernel/debug/iommu/amd/iommu00/capability_dump

Same comment here. Why does this need to be so complicated to use?
Can't you make a single read-only file that contains all the registers
of interest?


Please do let me know your concerns and views on my comments in the previous patch.

With the implemented approach we do need separate files for mmio registers and capability registers input/output files as to understand if user input is mmio's offset or capability register's offset.

Thanks
Dheeraj

Bjorn