perf tools: Add machine_pid and vcpu to id_index

When injecting events from a guest perf.data file, the events will have
separate sample ID numbers. These ID numbers can then be used to determine
which machine an event belongs to. To facilitate that, add machine_pid and
vcpu to id_index records. For backward compatibility, these are added at
the end of the record, and the length of the record is used to determine
if they are present or not.

Note, this is needed because the events from a guest perf.data file contain
the pid/tid of the process running at that time inside the VM not the
pid/tid of the (QEMU) hypervisor thread. So a way is needed to relate
guest events back to the guest machine and VCPU, and using sample ID
numbers for that is relatively simple and convenient.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-11-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index 9f7ca070da87..c2dbd3e88885 100644
--- a/tools/lib/perf/include/perf/event.h
+++ b/tools/lib/perf/include/perf/event.h
@@ -237,6 +237,11 @@ struct id_index_entry {
 	__u64			 tid;
 };
 
+struct id_index_entry_2 {
+	__u64			 machine_pid;
+	__u64			 vcpu;
+};
+
 struct perf_record_id_index {
 	struct perf_event_header header;
 	__u64			 nr;