linux-kernel - Re: [RFC PATCH v6 27/29] x86/mm/pti: Implement a TLB flush immediately after a switch to kernel CR3

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Message-ID: <xhsmhtszfpf8n.mognet@vschneid-thinkpadt14sgen2i.remote.csb>
Date: Fri, 31 Oct 2025 10:55:36 +0100
From: Valentin Schneider <vschneid@...hat.com>
To: Frederic Weisbecker <frederic@...nel.org>
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Subject: Re: [RFC PATCH v6 27/29] x86/mm/pti: Implement a TLB flush
 immediately after a switch to kernel CR3

On 29/10/25 15:49, Frederic Weisbecker wrote:
> Le Wed, Oct 29, 2025 at 03:13:59PM +0100, Valentin Schneider a écrit :
>> Given we have ALTERNATIVE's in there I assume something like a
>> boot-time-driven static key could do, but I haven't found out yet if and
>> how that can be shoved in an ASM file.
>
> Right, I thought I had seen static keys in ASM already but I can't find it
> anymore. arch/x86/include/asm/jump_label.h is full of reusable magic
> though.
>

I got something ugly that /seems/ to work, now to spend twice the time to
clean it up :-)

> Thanks.
>
> --
> Frederic Weisbecker
> SUSE Labs