linux-kernel - Re: [PATCH v2 19/29] arm_mpam: Use a static key to indicate when mpam is enabled

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: <0d84faef-5a14-4f16-8612-d0e5dfc15985@arm.com>
Date: Fri, 3 Oct 2025 19:03:25 +0100
From: James Morse <james.morse@....com>
To: Jonathan Cameron <jonathan.cameron@...wei.com>
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
 linux-acpi@...r.kernel.org,
 D Scott Phillips OS <scott@...amperecomputing.com>,
 carl@...amperecomputing.com, lcherian@...vell.com,
 bobo.shaobowang@...wei.com, tan.shaopeng@...itsu.com,
 baolin.wang@...ux.alibaba.com, Jamie Iles <quic_jiles@...cinc.com>,
 Xin Hao <xhao@...ux.alibaba.com>, peternewman@...gle.com,
 dfustini@...libre.com, amitsinght@...vell.com,
 David Hildenbrand <david@...hat.com>, Dave Martin <dave.martin@....com>,
 Koba Ko <kobak@...dia.com>, Shanker Donthineni <sdonthineni@...dia.com>,
 fenghuay@...dia.com, baisheng.gao@...soc.com, Rob Herring <robh@...nel.org>,
 Rohit Mathew <rohit.mathew@....com>, Rafael Wysocki <rafael@...nel.org>,
 Len Brown <lenb@...nel.org>, Lorenzo Pieralisi <lpieralisi@...nel.org>,
 Hanjun Guo <guohanjun@...wei.com>, Sudeep Holla <sudeep.holla@....com>,
 Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 Danilo Krummrich <dakr@...nel.org>
Subject: Re: [PATCH v2 19/29] arm_mpam: Use a static key to indicate when mpam
 is enabled

Hi Jonathan,

On 12/09/2025 13:13, Jonathan Cameron wrote:
> On Wed, 10 Sep 2025 20:42:59 +0000
> James Morse <james.morse@....com> wrote:
> 
>> Once all the MSC have been probed, the system wide usable number of
>> PARTID is known and the configuration arrays can be allocated.
>>
>> After this point, checking all the MSC have been probed is pointless,
>> and the cpuhp callbacks should restore the configuration, instead of
>> just resetting the MSC.
>>
>> Add a static key to enable this behaviour. This will also allow MPAM
>> to be disabled in repsonse to an error, and the architecture code to
>> enable/disable the context switch of the MPAM system registers.
>>
>> Signed-off-by: James Morse <james.morse@....com>
> 
> Seems fine to me (other than the TODO move to arch code
> that should probably be resolved.

That is just to make it clear this isn't where it should live, its a quirk of moving
the arch code alter to reduce the number of trees this interacts with.
I've dropped the word 'TODO'...


> Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>


Thanks!

James