linux-kernel - Re: [PATCH RFC 09/20] RISC-V: Add Smcntrpmf extension parsing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240218-contort-profile-53593ed8d391@spud>
Date: Sun, 18 Feb 2024 12:50:06 +0000
From: Conor Dooley <conor@...nel.org>
To: Atish Patra <atishp@...osinc.com>
Cc: linux-kernel@...r.kernel.org, Adrian Hunter <adrian.hunter@...el.com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Alexandre Ghiti <alexghiti@...osinc.com>,
	Andrew Jones <ajones@...tanamicro.com>,
	Anup Patel <anup@...infault.org>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Atish Patra <atishp@...shpatra.org>,
	Christian Brauner <brauner@...nel.org>,
	Clément Léger <cleger@...osinc.com>,
	devicetree@...r.kernel.org, Evan Green <evan@...osinc.com>,
	Guo Ren <guoren@...nel.org>, Heiko Stuebner <heiko@...ech.de>,
	Ian Rogers <irogers@...gle.com>, Ingo Molnar <mingo@...hat.com>,
	James Clark <james.clark@....com>,
	Jing Zhang <renyu.zj@...ux.alibaba.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Ji Sheng Teoh <jisheng.teoh@...rfivetech.com>,
	John Garry <john.g.garry@...cle.com>,
	Jonathan Corbet <corbet@....net>,
	Kan Liang <kan.liang@...ux.intel.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	kvm-riscv@...ts.infradead.org, kvm@...r.kernel.org,
	Ley Foon Tan <leyfoon.tan@...rfivetech.com>,
	linux-doc@...r.kernel.org, linux-perf-users@...r.kernel.org,
	linux-riscv@...ts.infradead.org,
	Mark Rutland <mark.rutland@....com>,
	Namhyung Kim <namhyung@...nel.org>,
	Palmer Dabbelt <palmer@...belt.com>,
	Paul Walmsley <paul.walmsley@...ive.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Rob Herring <robh+dt@...nel.org>,
	Samuel Holland <samuel.holland@...ive.com>,
	Weilin Wang <weilin.wang@...el.com>, Will Deacon <will@...nel.org>,
	kaiwenxue1@...il.com, Yang Jihong <yangjihong1@...wei.com>
Subject: Re: [PATCH RFC 09/20] RISC-V: Add Smcntrpmf extension parsing

On Fri, Feb 16, 2024 at 04:57:27PM -0800, Atish Patra wrote:
> Smcntrpmf extension allows M-mode to enable privilege mode filtering
> for cycle/instret counters. However, the cyclecfg/instretcfg CSRs are
> only available only in Ssccfg only Smcntrpmf is present.

There's some typos in this opening paragraph that makes it hard to
follow.

> 
> That's why, kernel needs to detect presence of Smcntrpmf extension and
> enable privilege mode filtering for cycle/instret counters.
> 
> Signed-off-by: Atish Patra <atishp@...osinc.com>
> ---
>  arch/riscv/include/asm/hwcap.h | 1 +
>  arch/riscv/kernel/cpufeature.c | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index 5f4401e221ee..b82a8d7a9b3b 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -84,6 +84,7 @@
>  #define RISCV_ISA_EXT_SMCSRIND		75
>  #define RISCV_ISA_EXT_SSCCFG            76
>  #define RISCV_ISA_EXT_SMCDELEG          77
> +#define RISCV_ISA_EXT_SMCNTRPMF         78
>  
>  #define RISCV_ISA_EXT_MAX		128
>  #define RISCV_ISA_EXT_INVALID		U32_MAX
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 77cc5dbd73bf..c30be2c924e7 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -302,6 +302,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
>  	__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
>  	__RISCV_ISA_EXT_DATA(smcdeleg, RISCV_ISA_EXT_SMCDELEG),
>  	__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
> +	__RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF),
>  	__RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND),
>  	__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
>  	__RISCV_ISA_EXT_DATA(sscsrind, RISCV_ISA_EXT_SSCSRIND),
> -- 
> 2.34.1
> 

Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)