From: Borislav Petkov <bp@alien8.de>
To: Ashok Raj <ashok.raj@intel.com>
Cc: "Ashok Raj" <ashok_raj@linux.intel.com>,
"X86 ML" <x86@kernel.org>, "Andrew Cooper" <amc96@srcf.net>,
LKML <linux-kernel@vger.kernel.org>,
"Ștefan Talpalaru" <stefantalpalaru@yahoo.com>
Subject: Re: [PATCH] x86/microcode/AMD: Attempt applying on every logical thread
Date: Wed, 17 Aug 2022 23:56:02 +0200 [thread overview]
Message-ID: <Yv1j8v7o3lOniUoH@zn.tnic> (raw)
In-Reply-To: <Yv1WXxcIXSQ7nMji@araj-dh-work>
On Wed, Aug 17, 2022 at 08:58:07PM +0000, Ashok Raj wrote:
> For this specific patch in question, its not for testing though.. Its
> required for functional purposes?
From its commit message:
"However, there are microcode patches which do per-thread modification,
see Link tag below.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216211"
TL;DR - the application needs to happen on *every* logical CPU.
> In effect you can test applying the same microcode over and over again
> without having any special patches.
Right now, you cannot downgrade on Zen but apparently applying the same
patch over and over again works.
The patch cache still has a version check and that prevents it but
that's ugly.
I need to test how it behaves on older families first and then think
about how to do this right. Maybe use cpuinfo_x86.microcode to record
what has been applied until now...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2022-08-17 21:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-14 12:00 [PATCH] x86/microcode/AMD: Attempt applying on every logical thread Borislav Petkov
2022-08-16 9:00 ` Ashok Raj
2022-08-16 12:41 ` Borislav Petkov
2022-08-16 16:51 ` Ashok Raj
2022-08-17 12:12 ` Ashok Raj
2022-08-17 14:23 ` Borislav Petkov
2022-08-17 15:29 ` Ashok Raj
2022-08-17 18:13 ` Borislav Petkov
2022-08-17 20:58 ` Ashok Raj
2022-08-17 21:56 ` Borislav Petkov [this message]
2022-08-18 9:58 ` Ashok Raj
2022-11-05 3:45 ` Ashok Raj
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