[PATCH i-g-t v7 3/7] lib/igt_sriov_device: add helper for checking if VF DRM driver is probed

[Kamil Konieczny]

Hi Lukasz,
On 2023-12-05 at 09:16:14 +0100, Lukasz Laguna wrote:
> From: Daniel Mrzyglod <daniel.t.mrzyglod at intel.com>
> 
> Probe check is based on existence of the DRM subsystem attribute in
> sysfs.
> 
> Cc: Marcin Bernatowicz <marcin.bernatowicz at linux.intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Signed-off-by: Daniel Mrzyglod <daniel.t.mrzyglod at intel.com>
> Signed-off-by: Lukasz Laguna <lukasz.laguna at intel.com>

Reviewed-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>

> ---
>  lib/igt_sriov_device.c | 29 +++++++++++++++++++++++++++++
>  lib/igt_sriov_device.h |  1 +
>  2 files changed, 30 insertions(+)
> 
> diff --git a/lib/igt_sriov_device.c b/lib/igt_sriov_device.c
> index 36116058a..c643f47d1 100644
> --- a/lib/igt_sriov_device.c
> +++ b/lib/igt_sriov_device.c
> @@ -258,3 +258,32 @@ int igt_sriov_open_vf_drm_device(int pf, unsigned int vf_num)
>  
>  	return __drm_open_device(dev_name, DRIVER_ANY);
>  }
> +
> +/**
> + * igt_sriov_is_vf_drm_driver_probed - Check if VF DRM driver is probed
> + * @pf: PF device file descriptor
> + * @vf_num: VF number (1-based to identify single VF)
> + *
> + * Verify if DRM driver is bound to VF device. Probe check is based on
> + * existence of the DRM subsystem attribute in sysfs.
> + *
> + * Returns:
> + * True if VF has DRM driver loaded, false if not.
> + */
> +bool igt_sriov_is_vf_drm_driver_probed(int pf, unsigned int vf_num)
> +{
> +	char path[PATH_MAX];
> +	int sysfs;
> +	bool ret;
> +
> +	igt_assert(vf_num > 0);
> +
> +	sysfs = igt_sysfs_open(pf);
> +	igt_assert_fd(sysfs);
> +	/* vf_num is 1-based, but virtfn is 0-based */
> +	snprintf(path, sizeof(path), "device/virtfn%u/drm", vf_num - 1);
> +	ret = igt_sysfs_has_attr(sysfs, path);
> +	close(sysfs);
> +
> +	return ret;
> +}
> diff --git a/lib/igt_sriov_device.h b/lib/igt_sriov_device.h
> index 2baf183fb..ddbda6cd6 100644
> --- a/lib/igt_sriov_device.h
> +++ b/lib/igt_sriov_device.h
> @@ -24,5 +24,6 @@ bool igt_sriov_is_driver_autoprobe_enabled(int pf);
>  void igt_sriov_enable_driver_autoprobe(int pf);
>  void igt_sriov_disable_driver_autoprobe(int pf);
>  int igt_sriov_open_vf_drm_device(int pf, unsigned int vf_num);
> +bool igt_sriov_is_vf_drm_driver_probed(int pf, unsigned int vf_num);
>  
>  #endif /* __IGT_SRIOV_DEVICE_H__ */
> -- 
> 2.40.0
>