[RESEND v5 2/2] tracing: Include Microcode Revision in mce_record tracepoint

From: Avadhut Naik
Date: Thu Mar 28 2024 - 20:22:19 EST


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 2e339ac9d706..c7d0edc778c3 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: %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