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[PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint

Avadhut Naik posted 2 patches 1 year, 10 months ago
There is a newer version of this series
[PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint
Posted by Avadhut Naik 1 year, 10 months ago 
Currently, the microcode field (Microcode Revision) of struct mce is not
exported to userspace through the mce_record tracepoint.

Knowing the microcode version on which the MCE was received is critical
information for debugging. If the version is not recorded, later attempts
to acquire the version might result in discrepancies since it can be
changed at runtime.

Export microcode version through the tracepoint to prevent ambiguity over
the active version on the system when the MCE was received.

Signed-off-by: Avadhut Naik <avadhut.naik@amd.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 include/trace/events/mce.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/mce.h b/include/trace/events/mce.h
index 959ba7b775b1..69438550252c 100644
--- a/include/trace/events/mce.h
+++ b/include/trace/events/mce.h
@@ -42,6 +42,7 @@ TRACE_EVENT(mce_record,
 		__field(	u8,		cs		)
 		__field(	u8,		bank		)
 		__field(	u8,		cpuvendor	)
+		__field(	u32,		microcode	)
 	),
 
 	TP_fast_assign(
@@ -63,9 +64,10 @@ TRACE_EVENT(mce_record,
 		__entry->cs		= m->cs;
 		__entry->bank		= m->bank;
 		__entry->cpuvendor	= m->cpuvendor;
+		__entry->microcode	= m->microcode;
 	),
 
-	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x",
+	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x, MICROCODE REVISION: %x",
 		__entry->cpu,
 		__entry->mcgcap, __entry->mcgstatus,
 		__entry->bank, __entry->status,
@@ -77,7 +79,8 @@ TRACE_EVENT(mce_record,
 		__entry->cpuvendor, __entry->cpuid,
 		__entry->walltime,
 		__entry->socketid,
-		__entry->apicid)
+		__entry->apicid,
+		__entry->microcode)
 );
 
 #endif /* _TRACE_MCE_H */
-- 
2.34.1
Re: [PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint
Posted by Sohil Mehta 1 year, 10 months ago 
On 3/27/2024 1:54 PM, Avadhut Naik wrote:

> -	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x",
> +	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x, MICROCODE REVISION: %x",

Nit: s/MICROCODE REVISION/MICROCODE/g

You could probably get rid of the word REVISION in the interest of
brevity similar to __print_mce().

	pr_emerg(HW_ERR "PROCESSOR %u:%x TIME %llu SOCKET %u APIC %x microcode
%x\n",
		m->cpuvendor, m->cpuid, m->time, m->socketid, m->apicid,
		m->microcode);


-Sohil
Re: [PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint
Posted by Naik, Avadhut 1 year, 10 months ago 

On 3/27/2024 17:31, Sohil Mehta wrote:
> On 3/27/2024 1:54 PM, Avadhut Naik wrote:
> 
>> -	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x",
>> +	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x, MICROCODE REVISION: %x",
> 
> Nit: s/MICROCODE REVISION/MICROCODE/g
> 
> You could probably get rid of the word REVISION in the interest of
> brevity similar to __print_mce().
> 
> 	pr_emerg(HW_ERR "PROCESSOR %u:%x TIME %llu SOCKET %u APIC %x microcode
> %x\n",
> 		m->cpuvendor, m->cpuid, m->time, m->socketid, m->apicid,
> 		m->microcode);
> 
>
Okay. Will remove "REVISION".
> -Sohil

-- 
Thanks,
Avadhut Naik
Re: [PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint
Posted by Borislav Petkov 1 year, 10 months ago 
On Wed, Mar 27, 2024 at 03:31:01PM -0700, Sohil Mehta wrote:
> On 3/27/2024 1:54 PM, Avadhut Naik wrote:
> 
> > -	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x",
> > +	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x, MICROCODE REVISION: %x",
> 
> Nit: s/MICROCODE REVISION/MICROCODE/g
> 
> You could probably get rid of the word REVISION in the interest of
> brevity similar to __print_mce().

You *definitely* want to do that - good catch.

And TBH, all the screaming words aren't helping either... :)

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette
[PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint
Posted by Naik, Avadhut 1 year, 10 months ago 

On 3/27/2024 17:35, Borislav Petkov wrote:
> On Wed, Mar 27, 2024 at 03:31:01PM -0700, Sohil Mehta wrote:
>> On 3/27/2024 1:54 PM, Avadhut Naik wrote:
>>
>>> -	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x",
>>> +	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR/MISC/SYND: %016Lx/%016Lx/%016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, PROCESSOR: %u:%x, TIME: %llu, SOCKET: %u, APIC: %x, MICROCODE REVISION: %x",
>>
>> Nit: s/MICROCODE REVISION/MICROCODE/g
>>
>> You could probably get rid of the word REVISION in the interest of
>> brevity similar to __print_mce().
> 
> You *definitely* want to do that - good catch.
> 
Will do.

> And TBH, all the screaming words aren't helping either... :)
> 
Are you suggesting to change the ALL CAPS format of words which are
not acronyms to normal Capitalization style? Like Sohit suggested
in his other mail on this thread?

Somewhat like below:

SOCKET -> Socket
PROCESSOR -> Processor
MICROCODE -> Microcode

-- 
Thanks,
Avadhut Naik
Re: [PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint
Posted by Borislav Petkov 1 year, 10 months ago 
On Thu, Mar 28, 2024 at 01:17:43AM -0500, Naik, Avadhut wrote:
> SOCKET -> Socket
> PROCESSOR -> Processor
> MICROCODE -> Microcode

SOCKET -> socket
PROCESSOR -> processor
MICROCODE -> microcode

And yeah, the acronyms need to obviously stay in all caps.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette
Re: [PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint
Posted by Sohil Mehta 1 year, 10 months ago 
> 
> You *definitely* want to do that - good catch.
> 
> And TBH, all the screaming words aren't helping either... :)
> 

:) I thought the same as well. But, I felt inconsistently screaming
words might be worse. Maybe just update all the words that are not
acronyms (such as Processor, Time, Socket, etc.)
RE: [PATCH v4 2/2] tracing: Include Microcode Revision in mce_record tracepoint
Posted by Luck, Tony 1 year, 10 months ago 
> Export microcode version through the tracepoint to prevent ambiguity over
> the active version on the system when the MCE was received.
>
> Signed-off-by: Avadhut Naik <avadhut.naik@amd.com>
> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Reviewed-by: Tony Luck <tony.luck@intel.com>

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