sema-svc: never apply swept-page releases with no live channel (guest boot corruption); tooling guards

1 files changed, 8 insertions, 2 deletions

diff --git a/tools/guest-diag/semfix_uvmt.py b/tools/guest-diag/semfix_uvmt.py
index 12577ab..0d31394 100755
--- a/tools/guest-diag/semfix_uvmt.py
+++ b/tools/guest-diag/semfix_uvmt.py
@@ -115,11 +115,17 @@ def state_str(sem, st):
 
 
 def dmesg_releases(seen):
-    """Print/append new host-decoded releases (sema-push lines)."""
+    """Print/append new host-decoded releases (sema-push lines).
+
+    Only lines after the last "sema-svc: thread started" marker count: dmesg
+    keeps the previous module load's lines and the old client's releases.
+    """
     try:
         r = subprocess.run(
             ["sudo", "-n", "sh", "-c",
-             "dmesg -T | grep 'sema-push' | tail -300"],
+             "dmesg -T | awk '/sema-svc: thread started/{n=NR} "
+             "{l[NR]=$0} END{for(i=n+1;i<=NR;i++) print l[i]}' "
+             "| grep 'sema-push' | tail -300"],
             capture_output=True, text=True, timeout=10)
     except Exception:
         return