guest-diag: stream uvbp pushbuffer kptrs for immediate pinning

The first CE channel's push-buffer was only pinned ~1 minute after the
client's failure: uvbp fired at t+4s but semfix's trace read (guest agent,
every 5 loops) picked it up at t+70s, so the tracker wait for value 3 spun
for 16 s. The guest scanner now emits '#pb 0x<kptr>' from the uvbp trace
lines as soon as they appear; the host mirrors them into the sem stream and
semfix resolves/pins the push-buffer through the UVM chain on the next loop
(sub-second).

1 files changed, 13 insertions, 0 deletions

diff --git a/tools/guest-diag/semfix_uvmt.py b/tools/guest-diag/semfix_uvmt.py
index fd58299..09cc5f8 100755
--- a/tools/guest-diag/semfix_uvmt.py
+++ b/tools/guest-diag/semfix_uvmt.py
@@ -63,6 +63,8 @@ class Stream:
         self.off = 0
         self.sems = []
         self.pids = []
+        self.pbs = []
+        self.new_pbs = []
 
     def poll(self):
         try:
@@ -77,6 +79,7 @@ class Stream:
         except OSError:
             return [], []
         new_sems, new_pids = [], []
+        self.new_pbs = []
         for line in data.splitlines():
             if line.startswith("#sem"):
                 m = re.search(r"0x([0-9a-fA-F]+)", line)
@@ -85,6 +88,13 @@ class Stream:
                     if v not in self.sems:
                         self.sems.append(v)
                         new_sems.append(v)
+            elif line.startswith("#pb"):
+                m = re.search(r"0x([0-9a-fA-F]+)", line)
+                if m:
+                    v = int(m.group(1), 16)
+                    if v not in self.pbs:
+                        self.pbs.append(v)
+                        self.new_pbs.append(v)
             elif line.startswith("#pid"):
                 m = re.search(r"(\d+)", line)
                 if m:
@@ -265,6 +275,9 @@ def main():
         for p in new_pids:
             log("stream: client pid %d" % p)
             last_pid = p
+        for pb in getattr(stream, "new_pbs", []):
+            log("stream: new pushbuffer 0x%x" % pb)
+            pbs.add(pb)
         sems.update(stream.sems)
 
         # The guest-agent trace read is slow under client load; use it only