Re: [PATCH v3 8/8] perf vendor events riscv:: Add support for spacemit,riscv-iommu HPM aliasing

Lv Zheng
2026-02-05T03:23:39Z

On 2/5/2026 1:38 AM, Conor Dooley wrote:
> On Wed, Feb 04, 2026 at 05:09:52PM +0800, Lv Zheng wrote:
>> Add JSON HPM event aliases for SpacemiT distributed IOMMU (T100) which is
>> general and compatible for all SpacemiT RISC-V SoCs.
>>
>> Signed-off-by: Lv Zheng <lv.zheng@linux.spacemit.com>
>> Signed-off-by: Jingyu Li <joey.li@spacemit.com>
>> ---
>> MAINTAINERS | 3 +
>> .../arch/riscv/spacemit/iommu/sys/ioatc.json | 30 ++++
>> .../arch/riscv/spacemit/iommu/sys/ioats.json | 163 ++++++++++++++++++
>> 3 files changed, 196 insertions(+)
>> create mode 100644 tools/perf/pmu-events/arch/riscv/spacemit/iommu/sys/ioatc.json
>> create mode 100644 tools/perf/pmu-events/arch/riscv/spacemit/iommu/sys/ioats.json
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 7c50701b6001..4d91f99aa742 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -22459,12 +22459,15 @@ K: riscv
>>
>> RISC-V IOMMU
>> M: Tomasz Jeznach <tjeznach@rivosinc.com>
>> +M: Lv Zheng <lv.zheng@linux.spacemit.com>
>> +M: Jingyu Li <joey.li@spacemit.com>
>
> To be frank, this looks misguided, or at least premature, to me, given the
> state of the patchset.

Should this be a big deal?
I've been working as kernel maintainers for 5 years (you can find me in
git log using Lv Zheng <lv.zheng@intel.com>) and given the fact that I'm
also the silicon designer of SpacemiT T100, played an active role in
IOMMU spec community, I'm ready to help the community by reviewing
RISC-V IOMMU related changes.
Joey is responsible for SpacemiT RISC-V linux kernel support. We have
chances to test RISC-V linux kernel supports very early using
pre-silicon real hardware here in a silicon team to help the community.
Any suggestions?

>
>> L: iommu@lists.linux.dev
>> L: linux-riscv@lists.infradead.org
>> S: Maintained
>> T: git git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux.git
>> F: Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
>> F: drivers/iommu/riscv/
>> +F: tools/perf/pmu-events/arch/riscv/spacemit/iommu/

checkpatch.pl complains missing files and given the reason above, I
didn't create a "Supported" part of RISC-V IOMMU HPM.

Best regards,
Lv