wall-2 session-77: vkCreateDevice PASSES - r682 0x7E event validated live (registered slot 13, EVPOST rc=0) and the completion word found/driven: the main-thread wait reads a u32 at +0x80 of a 16 KB rw-s /dev/nvidiactl notification mapping (should-wait = word != 1); a host write of 1 via the guest RAM file (PA from pagemap, file offset PA-0x80000000 above 4G) flips the wait and vkCreateDevice returns success (VKDEVICE ok family=0) - reproduced 3x (r683 manual, r684 nudger, r684d probe+single-word). Tools: t79.py (wait-chain resolver), guest_words.sh, nudge.sh; README-session77.md records the recipe, the residual guest event-dispatch gap (records consumed, notification word not written), and the -4/gdb-attach cautions.

1 files changed, 27 insertions, 0 deletions

diff --git a/tools/guest-diag/wall2/nudge.sh b/tools/guest-diag/wall2/nudge.sh
new file mode 100755
index 0000000..143b1cd
--- /dev/null
+++ b/tools/guest-diag/wall2/nudge.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+# nudge.sh - host-side readiness-word nudger for the vk_frame wait.
+# Polls the guest for the 16 KB nvidiactl mapping words (guest_words.sh),
+# and writes 1 to any that are still 0 in the guest RAM file.
+# Usage: nudge.sh <duration_seconds>
+DUR=${1:-300}
+F=/dev/shm/vgpu-guest-ram
+END=$(( $(date +%s) + DUR ))
+sshpass -p ubuntu scp -o StrictHostKeyChecking=no -P 2222 /tmp/opencode/guest_words.sh ubuntu@127.0.0.1:/tmp/guest_words.sh >/dev/null 2>&1
+while [ "$(date +%s)" -lt "$END" ]; do
+  OUT=$(timeout 20 sshpass -p ubuntu ssh -o StrictHostKeyChecking=no -p 2222 ubuntu@127.0.0.1 "sudo bash /tmp/guest_words.sh" 2>/dev/null)
+  echo "[$(date +%H:%M:%S)] words:"; echo "$OUT"
+  echo "$OUT" | while read -r VA PA; do
+    [ -z "$PA" ] && continue
+    PAD=$((PA)); FOD=$((PAD - 0x80000000))
+    [ $FOD -lt 0 ] && continue
+    CUR=$(sudo dd if=$F bs=4 skip=$((FOD/4)) count=1 2>/dev/null | xxd -p)
+    if [ "$CUR" = "00000000" ]; then
+      printf '\x01\x00\x00\x00' | sudo dd of=$F bs=1 seek=$FOD count=4 conv=notrunc 2>/dev/null
+      echo "  NUDGE $PA (va=$VA) -> 1"
+    else
+      echo "  skip $PA (va=$VA) = $CUR"
+    fi
+  done
+  sleep 2
+done
+echo NUDGE-DONE