On Mon, 23 Feb 2026 15:55:06 +0000
<ankita@nvidia.com> wrote:
> From: Ankit Agrawal <ankita@nvidia.com>
>
> Setup dummy auxiliary device ops to be able to get probed by
> the nvgrace-egm auxiliary driver.
>
> Both nvgrace-gpu and the out-of-tree nvidia-vgpu-vfio will make
> use of the EGM for device assignment and the SRIOV vGPU virtualization
> solutions respectively. Hence allow auxiliary device probing for both.
But only one is added?
Can you point to any other in-tree drivers that include out-of-tree
device entries in their ID table?
Isn't this ID table what should make the module soft-dep unnecessary?
>
> Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
> ---
> drivers/vfio/pci/nvgrace-gpu/egm.c | 38 +++++++++++++++++++++++++++---
> 1 file changed, 35 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/vfio/pci/nvgrace-gpu/egm.c b/drivers/vfio/pci/nvgrace-gpu/egm.c
> index 6bab4d94cb99..6fd6302a004a 100644
> --- a/drivers/vfio/pci/nvgrace-gpu/egm.c
> +++ b/drivers/vfio/pci/nvgrace-gpu/egm.c
> @@ -11,6 +11,29 @@
> static dev_t dev;
> static struct class *class;
>
> +static int egm_driver_probe(struct auxiliary_device *aux_dev,
> + const struct auxiliary_device_id *id)
> +{
> + return 0;
> +}
> +
> +static void egm_driver_remove(struct auxiliary_device *aux_dev)
> +{
> +}
> +
> +static const struct auxiliary_device_id egm_id_table[] = {
> + { .name = "nvgrace_gpu_vfio_pci.egm" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(auxiliary, egm_id_table);
> +
> +static struct auxiliary_driver egm_driver = {
> + .name = KBUILD_MODNAME,
> + .id_table = egm_id_table,
> + .probe = egm_driver_probe,
> + .remove = egm_driver_remove,
> +};
> +
> static char *egm_devnode(const struct device *device, umode_t *mode)
> {
> if (mode)
> @@ -35,17 +58,26 @@ static int __init nvgrace_egm_init(void)
>
> class = class_create(NVGRACE_EGM_DEV_NAME);
> if (IS_ERR(class)) {
> - unregister_chrdev_region(dev, MAX_EGM_NODES);
> - return PTR_ERR(class);
> + ret = PTR_ERR(class);
> + goto unregister_chrdev;
> }
>
> class->devnode = egm_devnode;
>
> - return 0;
> + ret = auxiliary_driver_register(&egm_driver);
> + if (!ret)
> + goto fn_exit;
This is not a good success oriented flow. The error condition should
goto the unwind, the success condition can just fall through to return.
Thanks,
Alex
> +
> + class_destroy(class);
> +unregister_chrdev:
> + unregister_chrdev_region(dev, MAX_EGM_NODES);
> +fn_exit:
> + return ret;
> }
>
> static void __exit nvgrace_egm_cleanup(void)
> {
> + auxiliary_driver_unregister(&egm_driver);
> class_destroy(class);
> unregister_chrdev_region(dev, MAX_EGM_NODES);
> }