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, 24 insertions, 4 deletions

diff --git a/README.md b/README.md
index ab699d9..2f89f58 100644
--- a/README.md
+++ b/README.md
@@ -48,20 +48,40 @@ cd open-iov
 make                    # Builds kernel module, userspace lib, examples
 ```
 
+### Build NVIDIA OpenRM with vGPU VFIO Symbols
+
+**Critical**: The NVIDIA OpenRM `nvidia.ko` must be built with `KBUILD_EXTRA_SYMBOLS` pointing to `open-iov-vfio.ko`'s `Module.symvers` to resolve the vGPU VFIO interface symbols (`nvidia_vgpu_vfio_probe`, `nvidia_vgpu_vfio_remove`, etc.).
+
+```bash
+# Build Open-IOV kernel module first (generates Module.symvers)
+cd open-iov
+make kernel
+
+# Build NVIDIA OpenRM with vGPU VFIO symbols (use helper script)
+./scripts/build_nvidia_openrm.sh
+
+# Or manually:
+cd nvidia-open-gpu-kernel-modules/kernel-open
+KBUILD_EXTRA_SYMBOLS=$OPEN_IOV_ROOT/kernel/Module.symvers make -j$(nproc) modules
+```
+
 ### Install Kernel Module
 
 ```bash
 # Copy firmware
-sudo cp firmware/570-GSP/gsp-570.144.fwimage.bin /lib/firmware/
+sudo cp firmware/57X-GSP/570.144/gsp-570.144.fwimage.bin /lib/firmware/
+
+# Load NVIDIA OpenRM host driver (exports vGPU VFIO symbols)
+sudo insmod nvidia-open-gpu-kernel-modules/kernel-open/nvidia.ko
 
-# Load kernel module (emulation mode ON by default, auto-detects GSP capabilities)
+# Load Open-IOV host VFIO driver (with GSP emulation engine)
 sudo insmod kernel/open-iov-vfio.ko
 
-# Or load guest driver with emulation
+# Or load guest driver with emulation (legacy path)
 sudo insmod driver/gsp-vgpu.ko firmware_name=gsp-570.144.fwimage.bin
 
 # Verify
-dmesg -T | grep -E "gsp-vgpu|open-iov"
+dmesg -T | grep -E "gsp-vgpu|open-iov|nvidia"
 ls -la /dev/gsp-vgpu /dev/open-iov
 ```