[PATCH v6 2/2] tracing: Include Microcode Revision in mce_record tracepoint

[Avadhut Naik]

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@xxxxxxx>
Reviewed-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>
Reviewed-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
 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 294fccc329c1..f0f7b3cb2041 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: %016Lx, MISC: %016Lx, SYND: %016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, vendor: %u, CPUID: %x, time: %llu, socket: %u, APIC: %x",
+	TP_printk("CPU: %d, MCGc/s: %llx/%llx, MC%d: %016Lx, IPID: %016Lx, ADDR: %016Lx, MISC: %016Lx, SYND: %016Lx, RIP: %02x:<%016Lx>, TSC: %llx, PPIN: %llx, vendor: %u, CPUID: %x, time: %llu, socket: %u, APIC: %x, microcode: %x",
 		__entry->cpu,
 		__entry->mcgcap, __entry->mcgstatus,
 		__entry->bank, __entry->status,
@@ -80,7 +82,8 @@ TRACE_EVENT(mce_record,
 		__entry->cpuid,
 		__entry->walltime,
 		__entry->socketid,
-		__entry->apicid)
+		__entry->apicid,
+		__entry->microcode)
 );
 
 #endif /* _TRACE_MCE_H */
-- 
2.34.1