[Intel-xe] [PATCH v8 2/3] drm/xe: Notify Userspace when gt reset fails

[Rodrigo Vivi]

On Tue, Jul 25, 2023 at 09:21:14PM +0530, Himal Prasad Ghimiray wrote:
> Send uevent in case of gt reset failure. This intimation can be used by
> userspace monitoring tool to do the device level reset/reboot
> when GT reset fails. udevadm can be used to monitor the uevents.
> 
> v2:
> - Support only gt failure notification (Rodrigo)
> 
> v3
> - Rectify the comments in header file.
> 
> v4
> - Use pci kobj instead of drm kobj for notification.(Rodrigo)
> - Cleanup (Badal)
> 
> Cc: Aravind Iddamsetty <aravind.iddamsetty at intel.com>
> Cc: Tejas Upadhyay <tejas.upadhyay at intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Reviewed-by: Badal Nilawar <badal.nilawar at intel.com>
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>

Cc: Matt Roper Matt Roper <matthew.d.roper at intel.com>

> ---
>  drivers/gpu/drm/xe/xe_gt.c | 17 +++++++++++++++++
>  include/uapi/drm/xe_drm.h  |  8 ++++++++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
> index 3e32d38aeeea..f4766fb6bfdb 100644
> --- a/drivers/gpu/drm/xe/xe_gt.c
> +++ b/drivers/gpu/drm/xe/xe_gt.c
> @@ -8,6 +8,7 @@
>  #include <linux/minmax.h>
>  
>  #include <drm/drm_managed.h>
> +#include <drm/xe_drm.h>
>  
>  #include "regs/xe_gt_regs.h"
>  #include "xe_bb.h"
> @@ -500,6 +501,19 @@ static int do_gt_restart(struct xe_gt *gt)
>  	return 0;
>  }
>  
> +static void xe_uevent_gt_reset_failure(struct pci_dev *pdev, u8 id)
> +{
> +	char *reset_event[4];
> +
> +	reset_event[0] = XE_RESET_FAILED_UEVENT "=NEEDS_RESET";
> +	reset_event[1] = "RESET_FAILED=gt";
> +	reset_event[2] = kasprintf(GFP_KERNEL, "RESET_ID=%d", id);

should we also put which tile this is coming from?
Matt?

> +	reset_event[3] = NULL;
> +	kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, reset_event);

Himal, could you please paste here an example of the output of this event
when monitoring it with the:
$ udevadm monitor
?

> +
> +	kfree(reset_event[2]);
> +}
> +
>  static int gt_reset(struct xe_gt *gt)
>  {
>  	int err;
> @@ -550,6 +564,9 @@ static int gt_reset(struct xe_gt *gt)
>  	xe_device_mem_access_put(gt_to_xe(gt));
>  	xe_gt_err(gt, "reset failed (%pe)\n", ERR_PTR(err));
>  
> +	/* Notify userspace about gt reset failure */
> +	xe_uevent_gt_reset_failure(to_pci_dev(gt_to_xe(gt)->drm.dev), gt->info.id);
> +
>  	return err;
>  }
>  
> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> index 347351a8f618..fdacee0a27c5 100644
> --- a/include/uapi/drm/xe_drm.h
> +++ b/include/uapi/drm/xe_drm.h
> @@ -16,6 +16,14 @@ extern "C" {
>   * subject to backwards-compatibility constraints.
>   */
>  
> +/*
> + * Uevent generated by xe on it's pci node.
> + *
> + * XE_RESET_FAILED_UEVENT - Event is generated when attempt to reset engine
> + * fails. The value supplied with the event is always "NEEDS_RESET".
> + */
> +#define XE_RESET_FAILED_UEVENT "DEVICE_STATUS"
> +
>  /**
>   * struct xe_user_extension - Base class for defining a chain of extensions
>   *
> -- 
> 2.25.1
>