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, 31 insertions, 0 deletions

diff --git a/tools/guest-diag/vmrestart.sh b/tools/guest-diag/vmrestart.sh
new file mode 100755
index 0000000..dbe60ec
--- /dev/null
+++ b/tools/guest-diag/vmrestart.sh
@@ -0,0 +1,31 @@
+#!/bin/bash
+# vmrestart.sh - stop QEMU, reload open-iov-vfio.ko from the tree, fresh mdev,
+# relaunch the vGPU VM. Everything bounded so a stuck step cannot hang the
+# caller.
+set -u
+cd "$(dirname "$(readlink -f "$0")")/../.."
+
+sudo pkill -f qemu-system-x86_64 2>/dev/null
+sleep 4
+sudo rm -f /tmp/qemu-guest-agent.sock /tmp/qemu-qmp.sock
+
+for m in /sys/bus/mdev/devices/*; do
+    [ -d "$m" ] || continue
+    timeout 20 sudo sh -c "echo 1 > $m/remove" || echo "WARN: mdev remove timeout"
+done
+
+timeout 30 sudo rmmod open_iov_vfio || { echo "ERROR: rmmod failed"; exit 1; }
+sudo insmod kernel/open-iov-vfio.ko || { echo "ERROR: insmod failed"; exit 1; }
+
+U=$(uuidgen)
+echo "$U" | sudo tee /sys/class/mdev_bus/0000:01:00.0/mdev_supported_types/nvidia-nvidia-vgpu-turing/create >/dev/null
+sed -i "s|/sys/bus/mdev/devices/[0-9a-f-]*|/sys/bus/mdev/devices/$U|" tools/guest-diag/launch_qemu_rootport.run.sh
+mkdir -p /tmp/sockets/e726ba0b-204f-4ec9-91da-983ed7f41d06
+
+(setsid nohup tools/guest-diag/launch_qemu_rootport.run.sh > tools/guest-diag/run/qemu.log 2>&1 &)
+sleep 6
+if pgrep -f qemu-system-x86_64 >/dev/null; then
+    echo "VM up (mdev $U)"
+else
+    echo "VM FAILED"; tail -5 tools/guest-diag/run/qemu.log; exit 1
+fi