Linux-RISC-V Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Drew Fustini <fustini@kernel.org>
To: Zhanpeng Zhang <zhangzhanpeng.jasper@bytedance.com>
Cc: ben.horgan@arm.com, xiaqinxin@huawei.com, zengheng4@huawei.com,
	palmer@dabbelt.com, tony.luck@intel.com,
	reinette.chatre@intel.com, tomasz.jeznach@linux.dev,
	will@kernel.org, robin.murphy@arm.com, pjw@kernel.org,
	aou@eecs.berkeley.edu, alex@ghiti.fr, Dave.Martin@arm.com,
	james.morse@arm.com, babu.moger@amd.com, corbet@lwn.net,
	shuah@kernel.org, jgg@ziepe.ca, kevin.tian@intel.com,
	cuiyunhui@bytedance.com, yuanzhu@bytedance.com,
	iommu@lists.linux.dev, linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kselftest@vger.kernel.org, x86@kernel.org
Subject: Re: [RFC PATCH 0/7] riscv: iommu: Add QoS ID support for resctrl device assignment
Date: Wed, 5 Aug 2026 22:23:53 -0700	[thread overview]
Message-ID: <anQaaQvpEXFTRYvS@x1> (raw)
In-Reply-To: <20260714130657.46963-1-zhangzhanpeng.jasper@bytedance.com>

On Tue, Jul 14, 2026 at 09:06:50PM +0800, Zhanpeng Zhang wrote:
> This RFC extends RISC-V CBQRI/resctrl support to external requesters
> behind a RISC-V IOMMU.
[..]
> Open questions for this RFC:
> 
>   * whether a common resctrl "devices" file is the right ABI for
>     associating external requesters with a resource group;

I think a separate file is the right approach to avoid confusing iommu
groups with pids. 

I should note that James Morse had an ARM MPAM "extras" tree [1] which
carried an iommu_group assignment interface, using the same
iommu_group:<id> format, but writing it to the tasks file. However, Ben
Horgan clarified back in March [2] in a reply to Qinxin Xia that it is
no longer maintained. Ben also wrote that the interface would likely
change upstream. I've added Ben Horgan and Qinxin Xia to the CC list so
hopefully they can chime in.

I plan to review the patches in this series further but I didn't want to
delay any further in pointing out the above.

Thanks,
Drew

[1] https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/snapshot%2Bextras/v6.18-rc1
[2] https://lore.kernel.org/lkml/d13fdc75-b647-44f3-9657-d592353e8a1a@huawei.com/

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  parent reply	other threads:[~2026-08-06  5:24 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-14 13:06 [RFC PATCH 0/7] riscv: iommu: Add QoS ID support for resctrl device assignment Zhanpeng Zhang
2026-07-14 13:06 ` [RFC PATCH 1/7] iommu: Add group lookup by ID Zhanpeng Zhang
2026-07-14 14:03   ` Jason Gunthorpe
2026-07-15  2:54     ` Zhanpeng Zhang
2026-07-15  2:55     ` Zhanpeng Zhang
2026-07-14 13:06 ` [RFC PATCH 2/7] iommu: Add checked group device update helper Zhanpeng Zhang
2026-07-14 13:06 ` [RFC PATCH 3/7] resctrl: Add a devices file for external requester assignment Zhanpeng Zhang
2026-07-14 13:06 ` [RFC PATCH 4/7] iommu/riscv: Program QoS IDs for assigned groups Zhanpeng Zhang
2026-07-14 13:06 ` [RFC PATCH 5/7] iommu/riscv: Expose global QoS IDs in sysfs Zhanpeng Zhang
2026-07-14 13:06 ` [RFC PATCH 6/7] riscv_cbqri: Assign IOMMU groups to resource groups Zhanpeng Zhang
2026-07-14 13:06 ` [RFC PATCH 7/7] selftests/iommu: Add RISC-V IOMMU QoS smoke test Zhanpeng Zhang
2026-08-06  5:23 ` Drew Fustini [this message]
2026-08-06  8:42   ` [RFC PATCH 0/7] riscv: iommu: Add QoS ID support for resctrl device assignment Ben Horgan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=anQaaQvpEXFTRYvS@x1 \
    --to=fustini@kernel.org \
    --cc=Dave.Martin@arm.com \
    --cc=alex@ghiti.fr \
    --cc=aou@eecs.berkeley.edu \
    --cc=babu.moger@amd.com \
    --cc=ben.horgan@arm.com \
    --cc=corbet@lwn.net \
    --cc=cuiyunhui@bytedance.com \
    --cc=iommu@lists.linux.dev \
    --cc=james.morse@arm.com \
    --cc=jgg@ziepe.ca \
    --cc=kevin.tian@intel.com \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=palmer@dabbelt.com \
    --cc=pjw@kernel.org \
    --cc=reinette.chatre@intel.com \
    --cc=robin.murphy@arm.com \
    --cc=shuah@kernel.org \
    --cc=tomasz.jeznach@linux.dev \
    --cc=tony.luck@intel.com \
    --cc=will@kernel.org \
    --cc=x86@kernel.org \
    --cc=xiaqinxin@huawei.com \
    --cc=yuanzhu@bytedance.com \
    --cc=zengheng4@huawei.com \
    --cc=zhangzhanpeng.jasper@bytedance.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox