Re: [PATCH v2 i-g-t 2/6] lib/igt_sriov_device: add helper for resetting SR-IOV device

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

On 21.10.2024 22:07, Marcin Bernatowicz wrote:
> Reset is initiated by writing 1 to device's sysfs reset attribute.

FLR is not SR-IOV only concept, FLR can be supported by any other PCI
device, it's just mandatory for the VFs, so maybe these SR-IOV helpers
should be built on top native helpers:

igt_trigger_reset(dir)
{
	igt_sysfs_set(dir, "reset", "1")
}

igt_reset_device(fd)
{
	dir = igt_get_device_dir(fd)
	igt_trigger_reset(dir)
}

igt_sriov_get_vf_device_dir(fd, n)
{
	igt_assert(n);
	return ...("virtfn%u", n)
}

igt_sriov_reset_vf(fd, n)
{
	dir = igt_sriov_get_vf_device_dir(fd, n)
	igt_trigger_reset(dir)
}

> 
> Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
> Reviewed-by: Adam Miszczak <adam.miszczak@linux.intel.com>
> Cc: Adam Miszczak <adam.miszczak@linux.intel.com>
> Cc: Jakub Kolakowski <jakub1.kolakowski@intel.com>
> Cc: Lukasz Laguna <lukasz.laguna@intel.com>
> Cc: Michał Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Michał Winiarski <michal.winiarski@intel.com>
> Cc: Narasimha C V <narasimha.c.v@intel.com>
> Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
> Cc: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
> Cc: Tomasz Lis <tomasz.lis@intel.com>
> ---
>  lib/igt_sriov_device.c | 51 ++++++++++++++++++++++++++++++++++++++++++
>  lib/igt_sriov_device.h |  2 ++
>  2 files changed, 53 insertions(+)
> 
> diff --git a/lib/igt_sriov_device.c b/lib/igt_sriov_device.c
> index d20c74823..2b83cd43c 100644
> --- a/lib/igt_sriov_device.c
> +++ b/lib/igt_sriov_device.c
> @@ -413,3 +413,54 @@ int igt_sriov_device_sysfs_open(int pf, unsigned int vf_num)
>  
>  	return fd;
>  }
> +
> +/**
> + * igt_sriov_device_reset_exists:
> + * @pf: PF device file descriptor
> + * @vf_num: VF number (1-based to identify single VF) or 0 for PF
> + *
> + * Check if reset attribute exists for a given SR-IOV device.
> + *
> + * Returns:
> + * True if reset attribute exists, false otherwise.
> + */
> +bool igt_sriov_device_reset_exists(int pf, unsigned int vf_num)
> +{
> +	int sysfs;
> +	bool reset_exists;
> +
> +	sysfs = igt_sriov_device_sysfs_open(pf, vf_num);
> +	if (sysfs < 0)
> +		return false;
> +
> +	reset_exists = igt_sysfs_has_attr(sysfs, "reset");
> +	close(sysfs);
> +
> +	return reset_exists;
> +}
> +
> +/**
> + * igt_sriov_device_reset:
> + * @pf: PF device file descriptor
> + * @vf_num: VF number (1-based to identify single VF) or 0 for PF
> + *
> + * Trigger FLR on a given VF.
> + *
> + * Returns:
> + * True on success, false on failure.
> + */
> +bool igt_sriov_device_reset(int pf, unsigned int vf_num)
> +{
> +	int sysfs;
> +	bool ret;
> +
> +	sysfs = igt_sriov_device_sysfs_open(pf, vf_num);
> +	if (sysfs < 0)
> +		return false;
> +
> +	igt_debug("Initiating FLR on VF%d\n", vf_num);
> +	ret = igt_sysfs_set(sysfs, "reset", "1");
> +	close(sysfs);
> +
> +	return ret;
> +}
> diff --git a/lib/igt_sriov_device.h b/lib/igt_sriov_device.h
> index dc95a4c78..4b63ceb22 100644
> --- a/lib/igt_sriov_device.h
> +++ b/lib/igt_sriov_device.h
> @@ -31,6 +31,8 @@ bool igt_sriov_is_vf_drm_driver_probed(int pf, unsigned int vf_num);
>  void igt_sriov_bind_vf_drm_driver(int pf, unsigned int vf_num);
>  void igt_sriov_unbind_vf_drm_driver(int pf, unsigned int vf_num);
>  int igt_sriov_device_sysfs_open(int pf, unsigned int vf_num);
> +bool igt_sriov_device_reset_exists(int pf, unsigned int vf_num);
> +bool igt_sriov_device_reset(int pf, unsigned int vf_num);
>  
>  /**
>   * for_each_sriov_vf - Helper for running code on each VF