linux-kernel - Re: [ RFC, PATCH - 1/2, v2 ] x86-microcode: refactor microcode output messages

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Date:	Wed, 11 Nov 2009 17:07:22 +0100
From:	Dmitry Adamushko <dmitry.adamushko@...il.com>
To:	Andreas Herrmann <herrmann.der.user@...glemail.com>
Cc:	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>,
	"H. Peter Anvin" <hpa@...or.com>, Mike Travis <travis@....com>,
	Tigran Aivazian <tigran@...azian.fsnet.co.uk>,
	Thomas Gleixner <tglx@...utronix.de>,
	Borislav Petkov <borislav.petkov@....com>,
	Andreas Mohr <andi@...as.de>, Jack Steiner <steiner@....com>
Subject: Re: [ RFC, PATCH - 1/2, v2 ] x86-microcode: refactor microcode output 
	messages

2009/11/7 Dmitry Adamushko <dmitry.adamushko@...il.com>:
> 2009/11/6 Andreas Herrmann <herrmann.der.user@...glemail.com>:
>> On Fri, Nov 06, 2009 at 01:56:31PM +0100, Dmitry Adamushko wrote:
>>> 2009/11/6 Andreas Herrmann <herrmann.der.user@...glemail.com>:
>>
>>   <snip>
>>
>>> >> (CPU3 belongs to both sets) unless summarize_cpu_info() is utterly
>>> >> broken.
>>> >
>>> > I didn't check that yet.
>>>
>>> Yeah, this behavior is likely due to a missing cpumask_clear() in
>>> summarize_cpu_info().
>>
>> Yeah, that fixes the wrong messages.
>> The other problem of not-updated CPU microcode after suspend/resume persists.
>>
>>> should be as follows:
>>>
>>>       if (!alloc_cpumask_var(&cpulist, GFP_KERNEL))
>>>               return;
>>>
>>> +    cpumask_clear(cpulist);
>>
>> Better use zalloc_cpumask instead of alloc/clear.
>
> ok.
>
>>
>>> >> sure, my test is somewhat limited... anyway, first of all I'd like to
>>> >> get a clear understanding of your logs. Thanks for yout test btw. :-))
>>> >
>>> > I'll send you full logs asap.
>>>
>>> Thanks. Maybe it's something about a particular sequence of actions
>>> that triggers this behavior. Or was it reproducible with the very
>>> first pm-suspend invocation after "modprobe microcode.ko"?
>>
>> The sequence is:
>>
>> 1. loading microcode.ko
>> 2. setting cpu2 offline
>> 3. setting cpu2 online
>> 4. suspend (pm-suspend)
>> 5. resume
>>
>> microcode of CPU2 is not updated:
>>
>>  # for i in `seq 0 3`; do lsmsr -c $i PATCH_LEVEL; done
>>  PATCH_LEVEL          = 0x0000000001000083
>>  PATCH_LEVEL          = 0x0000000001000083
>>  PATCH_LEVEL          = 0x0000000001000065
>>  PATCH_LEVEL          = 0x0000000001000083
>>
>> dmesg attached.
>
> It looks like the microcode of CPU2 was not updated at step (3) [ and
> not cached in uci->mc so that there was nothing to be loaded at resume
> time later on ].
>
> ...
> platform microcode: firmware: requesting amd-ucode/microcode_amd.bin
> microcode: size 1936, total_size 960
> microcode: CPU2: patch mismatch (processor_rev_id: 1020, equiv_cpu_id: 1022)
> microcode: size 968, total_size 960
> PM: Syncing filesystems ... done.
> ...
>
> These messages are from ->request_microcode_fw() but then there is
> nothing from ->apply_microcode(). I'd expect to see "microcode: CPU%d:
> updated (new patch_level=0x%x)".
>
> So either request_fw() -> generic_load_microcode() somehow fails to
> find/cache a ucode (while it could do this at microcode-load time) or
> apply_microcode_on_target() -> smp_call_function_single() fails in
> this context. I made a test (some changes to load a cached ->mc at
> cpu-online time) to verify the latter hypothesis and it didn't reveal
> any problems or it requires some special conditions (also my kernel is
> -rc5+).

Andreas,


any progress with this issue? You mentioned that the problem is also
reproducible without my patches, right?


--Dmitry
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