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From:   Ricardo =?utf-8?Q?Ca=C3=B1uelo?= <ricardo.canuelo@collabora.com>
To:     Borislav Petkov <bp@alien8.de>
Cc:     linux-kernel@vger.kernel.org,
        Thadeu Lima de Souza Cascardo <cascardo@canonical.com>,
        Mark Gross <mgross@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        John Johansen <john.johansen@canonical.com>,
        Steve Beattie <sbeattie@ubuntu.com>, kernel@collabora.com,
        Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Subject: Re: [PATCH v2] x86/speculation/srbds: do not try to turn mitigation off when not supported
References: <20220330082026.1549073-1-ricardo.canuelo@collabora.com> <YkS3OKLS1Cixs9up@zn.tnic>
In-reply-to: <YkS3OKLS1Cixs9up@zn.tnic>
Date:   Thu, 31 Mar 2022 09:48:14 +0200
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Borislav Petkov <bp@alien8.de> writes:
> So we could also do the below to denote what the situation is and
> therefore clear the bug flag for such CPUs.
>
> The thing is: I want this to be as clear as possible because bugs.c is
> already a nightmare and just slapping more logic to it without properly
> thinking it through is going to be a serious pain to deal with later...

Thanks Boris,

I agree that the more explicit the better, I'll give this a try. I saw
Pawan's suggestion as well but that one is similar to the originally
proposed patch in that the logic/checks are split between two functions,
this solution based on clearing the bug flag seems clearer considering
the comment just before the code block:

	/*
	 * Check to see if this is one of the MDS_NO systems supporting
	 * TSX that are only exposed to SRBDS when TSX is enabled.
	 */

Cheers,
Ricardo