perf intel-pt: Determine guest thread from guest sideband

Prior to decoding, determine what guest thread, if any, is running.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-33-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index dc2af64..a08c2f0 100644 (file)
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -196,6 +196,10 @@ struct intel_pt_queue {
        struct machine *guest_machine;
        struct thread *guest_thread;
        struct thread *unknown_guest_thread;
+       pid_t guest_machine_pid;
+       pid_t guest_pid;
+       pid_t guest_tid;
+       int vcpu;
        bool exclude_kernel;
        bool have_sample;
        u64 time;
@@ -759,8 +763,13 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
        cpumode = intel_pt_nr_cpumode(ptq, *ip, nr);
 
        if (nr) {
-               if ((!symbol_conf.guest_code && cpumode != PERF_RECORD_MISC_GUEST_KERNEL) ||
-                   intel_pt_get_guest(ptq)) {
+               if (ptq->pt->have_guest_sideband) {
+                       if (!ptq->guest_machine || ptq->guest_machine_pid != ptq->pid) {
+                               intel_pt_log("ERROR: guest sideband but no guest machine\n");
+                               return -EINVAL;
+                       }
+               } else if ((!symbol_conf.guest_code && cpumode != PERF_RECORD_MISC_GUEST_KERNEL) ||
+                          intel_pt_get_guest(ptq)) {
                        intel_pt_log("ERROR: no guest machine\n");
                        return -EINVAL;
                }
@@ -1385,6 +1394,55 @@ static void intel_pt_first_timestamp(struct intel_pt *pt, u64 timestamp)
        }
 }
 
+static int intel_pt_get_guest_from_sideband(struct intel_pt_queue *ptq)
+{
+       struct machines *machines = &ptq->pt->session->machines;
+       struct machine *machine;
+       pid_t machine_pid = ptq->pid;
+       pid_t tid;
+       int vcpu;
+
+       if (machine_pid <= 0)
+               return 0; /* Not a guest machine */
+
+       machine = machines__find(machines, machine_pid);
+       if (!machine)
+               return 0; /* Not a guest machine */
+
+       if (ptq->guest_machine != machine) {
+               ptq->guest_machine = NULL;
+               thread__zput(ptq->guest_thread);
+               thread__zput(ptq->unknown_guest_thread);
+
+               ptq->unknown_guest_thread = machine__find_thread(machine, 0, 0);
+               if (!ptq->unknown_guest_thread)
+                       return -1;
+               ptq->guest_machine = machine;
+       }
+
+       vcpu = ptq->thread ? ptq->thread->guest_cpu : -1;
+       if (vcpu < 0)
+               return -1;
+
+       tid = machine__get_current_tid(machine, vcpu);
+
+       if (ptq->guest_thread && ptq->guest_thread->tid != tid)
+               thread__zput(ptq->guest_thread);
+
+       if (!ptq->guest_thread) {
+               ptq->guest_thread = machine__find_thread(machine, -1, tid);
+               if (!ptq->guest_thread)
+                       return -1;
+       }
+
+       ptq->guest_machine_pid = machine_pid;
+       ptq->guest_pid = ptq->guest_thread->pid_;
+       ptq->guest_tid = tid;
+       ptq->vcpu = vcpu;
+
+       return 0;
+}
+
 static void intel_pt_set_pid_tid_cpu(struct intel_pt *pt,
                                     struct auxtrace_queue *queue)
 {
@@ -1405,6 +1463,13 @@ static void intel_pt_set_pid_tid_cpu(struct intel_pt *pt,
                if (queue->cpu == -1)
                        ptq->cpu = ptq->thread->cpu;
        }
+
+       if (pt->have_guest_sideband && intel_pt_get_guest_from_sideband(ptq)) {
+               ptq->guest_machine_pid = 0;
+               ptq->guest_pid = -1;
+               ptq->guest_tid = -1;
+               ptq->vcpu = -1;
+       }
 }
 
 static void intel_pt_sample_flags(struct intel_pt_queue *ptq)