VFIO device registration fix + IOMMUFD callbacks + VFIO ioctl handlers

- Removed IOMMU group addition before vfio_register_emulated_iommu_dev() in nv_vgpu_mdev_create()
- Added IOMMUFD callbacks (bind_iommufd, unbind_iommufd, attach_ioas, detach_ioas) using kernel's vfio_iommufd_emulated_* functions
- Implemented VFIO ioctl handlers: GET_INFO, GET_REGION_INFO, GET_IRQ_INFO, SET_IRQS, MMAP
- Added config space read/write handlers at offset 0x70000000000
- Mmap handler for config space, BAR0 (emulation shadow), BAR1-5 (physical VRAM/registers)
- Interrupt handler for VFIO_DEVICE_SET_IRQS (DATA_EVENTFD, DATA_NONE, DATA_BOOL)
- Added udev rules for vfio group permissions
- Created stack_manager.sh unified tool
- Fixed mdev remove crash with deferred cleanup in vfio_device_release callback
- Kernel 6.8+ IOMMUFD compatibility
- QEMU launches successfully with vGPU passthrough

1 files changed, 58 insertions, 0 deletions

diff --git a/scripts/qemu_gdb_attach.sh b/scripts/qemu_gdb_attach.sh
new file mode 100644
index 0000000..310c196
--- /dev/null
+++ b/scripts/qemu_gdb_attach.sh
@@ -0,0 +1,58 @@
+#!/bin/bash
+# qemu_gdb_attach.sh - Launch QEMU with GDB server for guest kernel debugging
+# Usage: ./qemu_gdb_attach.sh [gdb_port] [freeze_at_start]
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+BASE_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
+
+GDB_PORT="${1:-1234}"
+FREEZE="${2:-true}"  # -S flag to freeze at startup
+
+# Default QEMU command from launch_qemu_vgpu.sh
+QEMU_CMD=(
+    qemu-system-x86_64
+    -enable-kvm
+    -cpu host
+    -smp 4
+    -m 8G
+    -device vfio-pci,sysfsdev=/sys/bus/mdev/devices/$(cat /sys/bus/mdev/devices/*/uuid 2>/dev/null | head -1),display=off
+    -drive file=/var/lib/libvirt/images/ubuntu-vgpu.qcow2,format=qcow2,if=virtio
+    -netdev user,id=net0,hostfwd=tcp::2222-:22
+    -device virtio-net-pci,netdev=net0
+    -nographic
+    -serial mon:stdio
+)
+
+# Add GDB server options
+if [[ "$FREEZE" == "true" ]]; then
+    QEMU_CMD+=(-s -S)  # -s = gdbserver on :1234, -S = freeze at startup
+else
+    QEMU_CMD+=(-s)     # -s = gdbserver on :1234, run normally
+fi
+
+# Override port if specified
+if [[ "$GDB_PORT" != "1234" ]]; then
+    QEMU_CMD+=(-gdb "tcp::$GDB_PORT")
+fi
+
+echo "=========================================="
+echo "QEMU GDB Debug Launch"
+echo "=========================================="
+echo "GDB Port: $GDB_PORT"
+echo "Freeze at start: $FREEZE"
+echo "QEMU Command: ${QEMU_CMD[*]}"
+echo ""
+echo "In another terminal, connect with:"
+echo "  gdb ./vmlinux"
+echo "  (gdb) target remote localhost:$GDB_PORT"
+echo "  (gdb) break nvidia_probe"
+echo "  (gdb) continue"
+echo ""
+echo "Or use the GDB script:"
+echo "  gdb -x $BASE_DIR/tools/gdb_scripts/nvidia_init.gdb ./vmlinux"
+echo ""
+
+# Launch QEMU
+exec "${QEMU_CMD[@]}"
\ No newline at end of file