1 files changed, 54 insertions, 3 deletions

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index ec43d364d0de..62b2f375a94d 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -192,6 +192,7 @@ struct intel_pt_queue {
 	pid_t next_tid;
 	struct thread *thread;
 	struct machine *guest_machine;
+	struct thread *guest_thread;
 	struct thread *unknown_guest_thread;
 	pid_t guest_machine_pid;
 	bool exclude_kernel;
@@ -530,6 +531,7 @@ struct intel_pt_cache_entry {
 	u64				byte_cnt;
 	enum intel_pt_insn_op		op;
 	enum intel_pt_insn_branch	branch;
+	bool				emulated_ptwrite;
 	int				length;
 	int32_t				rel;
 	char				insn[INTEL_PT_INSN_BUF_SZ];
@@ -616,6 +618,7 @@ static int intel_pt_cache_add(struct dso *dso, struct machine *machine,
 	e->byte_cnt = byte_cnt;
 	e->op = intel_pt_insn->op;
 	e->branch = intel_pt_insn->branch;
+	e->emulated_ptwrite = intel_pt_insn->emulated_ptwrite;
 	e->length = intel_pt_insn->length;
 	e->rel = intel_pt_insn->rel;
 	memcpy(e->insn, intel_pt_insn->buf, INTEL_PT_INSN_BUF_SZ);
@@ -688,6 +691,11 @@ static int intel_pt_get_guest(struct intel_pt_queue *ptq)
 	ptq->guest_machine = NULL;
 	thread__zput(ptq->unknown_guest_thread);
 
+	if (symbol_conf.guest_code) {
+		thread__zput(ptq->guest_thread);
+		ptq->guest_thread = machines__findnew_guest_code(machines, pid);
+	}
+
 	machine = machines__find_guest(machines, pid);
 	if (!machine)
 		return -1;
@@ -702,6 +710,28 @@ static int intel_pt_get_guest(struct intel_pt_queue *ptq)
 	return 0;
 }
 
+static inline bool intel_pt_jmp_16(struct intel_pt_insn *intel_pt_insn)
+{
+	return intel_pt_insn->rel == 16 && intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL;
+}
+
+#define PTWRITE_MAGIC		"\x0f\x0bperf,ptwrite  "
+#define PTWRITE_MAGIC_LEN	16
+
+static bool intel_pt_emulated_ptwrite(struct dso *dso, struct machine *machine, u64 offset)
+{
+	unsigned char buf[PTWRITE_MAGIC_LEN];
+	ssize_t len;
+
+	len = dso__data_read_offset(dso, machine, offset, buf, PTWRITE_MAGIC_LEN);
+	if (len == PTWRITE_MAGIC_LEN && !memcmp(buf, PTWRITE_MAGIC, PTWRITE_MAGIC_LEN)) {
+		intel_pt_log("Emulated ptwrite signature found\n");
+		return true;
+	}
+	intel_pt_log("Emulated ptwrite signature not found\n");
+	return false;
+}
+
 static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
 				   uint64_t *insn_cnt_ptr, uint64_t *ip,
 				   uint64_t to_ip, uint64_t max_insn_cnt,
@@ -729,11 +759,16 @@ 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 (cpumode != PERF_RECORD_MISC_GUEST_KERNEL ||
+		if ((!symbol_conf.guest_code && cpumode != PERF_RECORD_MISC_GUEST_KERNEL) ||
 		    intel_pt_get_guest(ptq))
 			return -EINVAL;
 		machine = ptq->guest_machine;
-		thread = ptq->unknown_guest_thread;
+		thread = ptq->guest_thread;
+		if (!thread) {
+			if (cpumode != PERF_RECORD_MISC_GUEST_KERNEL)
+				return -EINVAL;
+			thread = ptq->unknown_guest_thread;
+		}
 	} else {
 		thread = ptq->thread;
 		if (!thread) {
@@ -764,6 +799,7 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
 				*ip += e->byte_cnt;
 				intel_pt_insn->op = e->op;
 				intel_pt_insn->branch = e->branch;
+				intel_pt_insn->emulated_ptwrite = e->emulated_ptwrite;
 				intel_pt_insn->length = e->length;
 				intel_pt_insn->rel = e->rel;
 				memcpy(intel_pt_insn->buf, e->insn,
@@ -795,8 +831,18 @@ static int intel_pt_walk_next_insn(struct intel_pt_insn *intel_pt_insn,
 
 			insn_cnt += 1;
 
-			if (intel_pt_insn->branch != INTEL_PT_BR_NO_BRANCH)
+			if (intel_pt_insn->branch != INTEL_PT_BR_NO_BRANCH) {
+				bool eptw;
+				u64 offs;
+
+				if (!intel_pt_jmp_16(intel_pt_insn))
+					goto out;
+				/* Check for emulated ptwrite */
+				offs = offset + intel_pt_insn->length;
+				eptw = intel_pt_emulated_ptwrite(al.map->dso, machine, offs);
+				intel_pt_insn->emulated_ptwrite = eptw;
 				goto out;
+			}
 
 			if (max_insn_cnt && insn_cnt >= max_insn_cnt)
 				goto out_no_cache;
@@ -1300,6 +1346,7 @@ static void intel_pt_free_queue(void *priv)
 	if (!ptq)
 		return;
 	thread__zput(ptq->thread);
+	thread__zput(ptq->guest_thread);
 	thread__zput(ptq->unknown_guest_thread);
 	intel_pt_decoder_free(ptq->decoder);
 	zfree(&ptq->event_buf);
@@ -2372,6 +2419,10 @@ static int intel_pt_sample(struct intel_pt_queue *ptq)
 		ptq->sample_ipc = ptq->state->flags & INTEL_PT_SAMPLE_IPC;
 	}
 
+	/* Ensure guest code maps are set up */
+	if (symbol_conf.guest_code && (state->from_nr || state->to_nr))
+		intel_pt_get_guest(ptq);
+
 	/*
 	 * Do PEBS first to allow for the possibility that the PEBS timestamp
 	 * precedes the current timestamp.