linux-kernel - Re: x86/microcode update on systems without INITRD

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Message-ID: <alpine.LSU.2.11.1601071308020.23854@er-systems.de>
Date:	Thu, 7 Jan 2016 13:12:16 +0100 (CET)
From:	Thomas Voegtle <tv@...96.de>
To:	Borislav Petkov <bp@...e.de>
cc:	Markus Trippelsdorf <markus@...ppelsdorf.de>,
	linux-kernel@...r.kernel.org
Subject: Re: x86/microcode update on systems without INITRD

On Fri, 20 Nov 2015, Borislav Petkov wrote:

> On Fri, Nov 20, 2015 at 08:19:20AM +0100, Markus Trippelsdorf wrote:
>> On 2015.11.19 at 23:58 +0100, Borislav Petkov wrote:
>>> On Thu, Nov 19, 2015 at 10:55:43PM +0100, Borislav Petkov wrote:
>>>> On Thu, Nov 19, 2015 at 10:43:01PM +0100, Markus Trippelsdorf wrote:
>>>>> It looks like the ability to update x86/microcode without using an
>>>>> initrd was removed this merge window.
>>>>
>>>> Whoops, that shouldnt've happened. Will debug it tomorrow and provide a
>>>> fix.
>>>
>>> Anyway, the hunk below seems to work in my guest here, I'll run it
>>> on the rest of the boxes tomorrow. In case you want to give it a try
>>> before:
>>
>> Your patch works fine. Thanks.
>
> Thanks for testing.
>
>> But of course it needs this additional patch, otherwise the microcode
>> loader wouldn't build at all:
>>
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index db3622f22b61..52c6964e24bd 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -1126,7 +1126,6 @@ config MICROCODE
>>  	bool "CPU microcode loading support"
>>  	default y
>>  	depends on CPU_SUP_AMD || CPU_SUP_INTEL
>> -	depends on BLK_DEV_INITRD
>>  	select FW_LOADER
>>  	---help---
>
> That dependency is a must as the early loader needs the initrd support.


I just diffed my 4.3 config with the 4.4 config and saw that the whole 
Microcode stuff was silently dropped by a normal "make oldconfig".

Wouldn't be something like this much nicer to give a hint?

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index db3622f..75523a0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1126,7 +1126,7 @@ config MICROCODE
         bool "CPU microcode loading support"
         default y
         depends on CPU_SUP_AMD || CPU_SUP_INTEL
-       depends on BLK_DEV_INITRD
+       select BLK_DEV_INITRD
         select FW_LOADER
         ---help---


At least I would have noticed it?


    Thomas





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