[External] [PATCH v4 0/3] RISC-V: Detect Ssqosid extension and handle srmcfg CSR

yunhui cui cuiyunhui at bytedance.com
Wed Dec 24 00:40:26 PST 2025


Hi Drew,

[3] https://lore.kernel.org/all/20250910204309.20751-1-james.morse@arm.com/
seems to have been merged into the mainline. Do you plan to submit a
series of ssqosid + cbqri patches with ACPI support?

Thanks,
Yunhui

On Sat, Oct 11, 2025 at 5:56 AM Drew Fustini <fustini at kernel.org> wrote:
>
> On Fri, Oct 10, 2025 at 08:23:50PM +0800, yunhui cui wrote:
> > Hi Drew,
> [snip]
> > > I think it makes sense to first focus on the detection of Ssqosid and
> > > handling of srmcfg when switching tasks. It has been tested against a
> > > QEMU branch that implements Ssqosid and CBQRI [6]. A test driver [7]
> > > was used to set srmcfg for the current process. This allows switch_to
> > > to be tested without resctrl.
> >
> > Could we consider submitting the entire QoS functionality as a single
> > integrated patchset (indicating the upstream branch that the patchset
> > is based on)? This should include the content from
> > https://lore.kernel.org/linux-riscv/20230419111111.477118-1-dfustini@baylibre.com/
>
> Thanks for the feedback. I had thought that submitting Ssqosid
> separately would streamline the review of the parts that most affects
> existing arch/riscv code (like switch_to.h) before adding code for CBQRI
> and resctrl integration.
>
> But I have gotten similar feedback from another person too. I can post a
> complete series that adds Ssqosid and CBQRI support including the
> resctrl interface. I have a cbqri branch [1] on top of riscv/for-next.
> I need to clean up some of the code, and then I can send a series with
> ssqosid+cbqri.
>
> That cbqri branch just has device tree support in order to demonstrate
> the resctrl functionality. However, I did also work on support for the
> ACPI RQSC table earlier this year for a proof of concept [2]. I have
> been thinking that I will hold back the ACPI support until after Ssqosid
> and CBQRI support is reviewed. It also depends on some improvements
> regarding the ACPI PPTT table that James Morse is currently working on for
> ARM MPAM support [3].
>
> Thanks,
> Drew
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/fustini/linux.git/log/?h=b4/cbqri
> [2] https://lf-rise.atlassian.net/wiki/spaces/HOME/pages/433291272/ACPI+RQSC+Proof+of+Concept
> [3] https://lore.kernel.org/all/20250910204309.20751-1-james.morse@arm.com/



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