lib: added params_size for v18 driver compatibility

In vGPU 18.x (R570)

- Parameters size for `NV0000_CTRL_CMD_VGPU_CREATE_DEVICE` was 40 bytes

- Parameters size for `NV0080_CTRL_CMD_GPU_GET_VIRTUALIZATION_MODE` was 8 bytes



Signed-off-by: Coia Prant <coiaprant@gmail.com>

src/lib.rs

@@ -394,7 +394,10 @@ pub unsafe extern "C" fn ioctl(fd: RawFd, request: c_ulong, argp: *mut c_void) -
             params.pci_sub_system_id = (orig_sub_system_id & 0xffff) | (spoofed_subsysid << 16);
         }
         NV0080_CTRL_CMD_GPU_GET_VIRTUALIZATION_MODE
-            if check_size!(
+        // 18.0 driver sends larger struct with size 8 bytes. Only extra members added at the end,
+        // nothing in between or changed, so accessing the larger struct is "safe"
+        if io_data.params_size == 8
+            || check_size!(
                 NV0080_CTRL_CMD_GPU_GET_VIRTUALIZATION_MODE,
                 Nv0080CtrlGpuGetVirtualizationModeParams
             ) && CONFIG.unlock =>
@@ -432,10 +435,13 @@ pub unsafe extern "C" fn ioctl(fd: RawFd, request: c_ulong, argp: *mut c_void) -
                 *LAST_MDEV_UUID.lock() = Some(config.mdev_uuid);
             }
             NV0000_CTRL_CMD_VGPU_CREATE_DEVICE
-                if check_size!(
-                    NV0000_CTRL_CMD_VGPU_CREATE_DEVICE,
-                    Nv0000CtrlVgpuCreateDeviceParams
-                ) =>
+                // 18.0 driver sends larger struct with size 40 bytes. Only extra members added at the end,
+                // nothing in between or changed, so accessing the larger struct is "safe"
+                if io_data.params_size == 40
+                    || check_size!(
+                        NV0000_CTRL_CMD_VGPU_CREATE_DEVICE,
+                        Nv0000CtrlVgpuCreateDeviceParams
+                    ) =>
             {
                 // 17.0 driver provides mdev uuid as vgpu_name in this command
                 let params: &mut Nv0000CtrlVgpuCreateDeviceParams = &mut *io_data.params.cast();