linux-kernel - Re: AMD EPYC microcode update bug?

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Message-ID: <59bfc45e-0741-2a45-fa5c-9b148b22e4ca@gmail.com>
Date:   Wed, 10 Jan 2018 00:37:48 +0100
From:   Gabriel C <nix.or.die@...il.com>
To:     Tom Lendacky <thomas.lendacky@....com>
Cc:     LKML <linux-kernel@...r.kernel.org>, Borislav Petkov <bp@...en8.de>
Subject: Re: AMD EPYC microcode update bug?

On 10.01.2018 00:06, Gabriel C wrote:
> 2018-01-09 23:47 GMT+01:00 Tom Lendacky <thomas.lendacky@....com>:
>> On 1/9/2018 4:28 PM, Gabriel C wrote:
>>> Hello ,
>>>
>>> I'm testing an EPYC system right now with 2 EPYC 7281 16-Core Processors.
>>>
>>> I'm on 4.15.0-rc7 and tested an update to microcode_amd_fam17h.bin.
>>>
>>> First run was made by using the early microcode option with dracut[1]
>>> so loading from a initrd. the driver reported 63 updated CPUs while CPU0
>>> got still old microcode.
>>
>> I'm guessing that memory encryption is enabled, correct?  I've submitted a
>> patch series to perform early initrd decryption for just this problem. I'm
>> incorporating some minor feedback and getting ready to submit the next
>> version.
> 
> Yes is correct I use mem_encrypt=on and SMT on in BIOS.
> 
> Can you give me an link to the patch series ?
> 
>>
>> In the meantime, if you specify mem_encrypt=off on the kernel command line
>> it should show CPU0 updated properly (with mem_encrypt=on and SMT enabled,
>> I believe it really does get updated when the sibling hread is updated -
>> do a rdmsr of 0x0000008b to verify).
>>
> 
> I give that an test in a bit , the box is running now some test for a
> different EPYC issue :)
> 
> ( https://community.amd.com/thread/224000 )
> 


With mem_encrypt=off all is working fine from a initrd with SMT ON

Reagrds,

Gabriel C