kernel: validate learned semaphore maps and post guest GPU events

- admit {GPU VA -> PA} pairs only when the preceding bytes form a valid
  client memory descriptor header (type 0/1, CPU+GPU mapped bits), prefer
  validated pairs over headerless candidates under first-wins dedup, and
  invalidate the translation cache on every rebuild; fixes stale identity
  entries shadowing live pool pages and lets the guest UVM channel
  bring-up complete on its own
- capture OS event allocations (class 0x79) and post event records
  (function 0x1003) into the guest status queue when a channel's busy
  notification is consumed, with a broadcast fallback, serialized with
  replies via a queue lock
- add BAR0 shadow introspection (dump_bar0/scan_bar0) and guest-side
  diagnostic scripts for the VM cycle

1 files changed, 21 insertions, 0 deletions

diff --git a/tools/guest-diag/pmap_va.sh b/tools/guest-diag/pmap_va.sh
new file mode 100755
index 0000000..e5bcef4
--- /dev/null
+++ b/tools/guest-diag/pmap_va.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+# pmap_va.sh <pid|name> <hex-va> [hex-va ...]
+# Push guest_pmap.py to the running VM and translate the VAs of the named
+# process through the guest's own pagemap (root in the guest).
+set -u
+cd "$(dirname "$0")/../.."
+
+TARGET="$1"; shift
+VAS="$*"
+
+B64=$(base64 -w0 tools/guest-diag/guest_pmap.py)
+timeout 30 ./scripts/vgpu_vm.py exec --timeout 25 \
+    "echo '$B64' | base64 -d > /tmp/pmap.py" >/dev/null 2>&1
+
+if ! [[ "$TARGET" =~ ^[0-9]+$ ]]; then
+    PID=$(timeout 20 ./scripts/vgpu_vm.py exec --timeout 15 "pgrep -x $TARGET | head -1" 2>/dev/null | tail -1)
+    [ -n "$PID" ] && TARGET="$PID"
+fi
+[ -n "$TARGET" ] || { echo "no pid found"; exit 1; }
+
+timeout 60 ./scripts/vgpu_vm.py exec --timeout 55 "sudo python3 /tmp/pmap.py $TARGET $VAS" 2>/dev/null | grep -E '^VA='