Date:   Wed, 1 Mar 2023 00:45:08 +0300 (MSK)
From:   Alexander Monakov <amonakov@ispras.ru>
To:     Andrew Cooper <andrew.cooper3@citrix.com>
cc:     Borislav Petkov <bp@alien8.de>, Tavis Ormandy <taviso@gmail.com>,
        linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: x86: AMD Zen2 ymm registers rolling back
In-Reply-To: <8eff0a18-7faa-1135-a558-40150f4443e5@citrix.com>
Message-ID: <a9ffb1f6-96ba-dab4-5f54-344e0abef4cd@ispras.ru>
References: <Y/W4x7/KFqmDmmR7@thinkstation.cmpxchg8b.net> <Y/XTT59OrLw2as4R@zn.tnic> <Y/Xc+yMzI83WZ4V1@zn.tnic> <0371ec3d-0899-f94a-7f21-21d805df2927@citrix.com> <Y/Xp73KJe3c/1jrn@zn.tnic> <4737f149-c5b7-8a51-7cc5-8bda6e98308b@ispras.ru> <Y/5T4ScbM/99DhgT@zn.tnic>
 <3d007f98-a42a-3c0e-8d6a-c86c5d0e25be@ispras.ru> <Y/5VIECduoyCJKP5@zn.tnic> <4d21fe93-7b77-bf5a-9ba8-645256ab0983@ispras.ru> <8eff0a18-7faa-1135-a558-40150f4443e5@citrix.com>
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On Tue, 28 Feb 2023, Andrew Cooper wrote:

> On 28/02/2023 7:29 pm, Alexander Monakov wrote:
> > On Tue, 28 Feb 2023, Borislav Petkov wrote:
> >
> > That I can reproduce the bug even with the latest BIOS, i.e. the microcode
> > in the latest BIOS update does not have the fix, and the linux-firmware.git
> > microcode does not have a patch for this CPU family at all.
> >
> > Hence the question how to get fixed microcode for this CPU family.
> 
> I shouldn't be recommending this, but I've begged AMD many times to be
> better at publishing microcode...
> 
> https://github.com/platomav/CPUMicrocodes
> 
> and you'll need
[snip script]

Thank you, this is good to have. Unfortunately, even with microcode 0x08600109
taken from that repo the issue is reproducible (it is dated 2022-03-28, so
perhaps not really surprising).

Alexander