Re: [PATCH v2] drm/xe/uapi: Bring back reset uevent

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Tue, Aug 13, 2024 at 04:28:32PM +0300, Raag Jadav wrote:
> On Mon, Aug 12, 2024 at 03:08:14PM +0530, Aravind Iddamsetty wrote:
> > 
> > On 12/08/24 13:18, Raag Jadav wrote:
> > > From: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> > >
> > > This was dropped in commit 77a0d4d1cea2 ("drm/xe/uapi: Remove reset
> > > uevent for now") as part of refactoring.
> > >
> > > Now that we have better uapi semantics and naming for the uevent,
> > > bring it back. With this in place, userspace will be notified of
> > > wedged device along with its reason.
> > >
> > > $ udevadm monitor --property --kernel
> > > monitor will print the received events for:
> > > KERNEL - the kernel uevent
> > >
> > > KERNEL[871.188570] change   /devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:01.0/0000:03:00.0 (pci)
> > > ACTION=change
> > > DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:01.0/0000:03:00.0
> > > SUBSYSTEM=pci
> > > DEVICE_STATUS=NEEDS_RESET
> > > REASON=GT_RESET_FAILED
> > > TILE_ID=0
> > > GT_ID=0
> > > DRIVER=xe
> > > PCI_CLASS=30000
> > > PCI_ID=8086:56B1
> > > PCI_SUBSYS_ID=8086:1210
> > > PCI_SLOT_NAME=0000:03:00.0
> > > MODALIAS=pci:v00008086d000056B1sv00008086sd00001210bc03sc00i00
> > > SEQNUM=6104
> > >
> > > v2: Change authorship to Himal (Aravind)
> > >     Add uevent for all device wedged cases (Aravind)
> > >
> > > Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> > > Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> > > ---
> > >  drivers/gpu/drm/xe/xe_device.c     | 10 +++++++++-
> > >  drivers/gpu/drm/xe/xe_device.h     |  2 +-
> > >  drivers/gpu/drm/xe/xe_gt.c         | 23 +++++++++++++++++++----
> > >  drivers/gpu/drm/xe/xe_guc.c        | 13 ++++++++++++-
> > >  drivers/gpu/drm/xe/xe_guc_submit.c | 13 ++++++++++++-
> > >  include/uapi/drm/xe_drm.h          | 29 +++++++++++++++++++++++++++++
> > >  6 files changed, 82 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> > > index 1aba6f9eaa19..d975bdce4a7d 100644
> > > --- a/drivers/gpu/drm/xe/xe_device.c
> > > +++ b/drivers/gpu/drm/xe/xe_device.c
> > > @@ -955,6 +955,7 @@ static void xe_device_wedged_fini(struct drm_device *drm, void *arg)
> > >  /**
> > >   * xe_device_declare_wedged - Declare device wedged
> > >   * @xe: xe device instance
> > > + * @event_params: parameters to be sent along with uevent
> > >   *
> > >   * This is a final state that can only be cleared with a mudule
> > >   * re-probe (unbind + bind).
> > > @@ -965,8 +966,10 @@ static void xe_device_wedged_fini(struct drm_device *drm, void *arg)
> > >   * on every single execution timeout (a.k.a. GPU hang) right after devcoredump
> > >   * snapshot capture. In this mode, GT reset won't be attempted so the state of
> > >   * the issue is preserved for further debugging.
> > > + * Caller is expected to pass respective parameters to be sent along with
> > > + * uevent. Pass NULL in case of no params.
> > >   */
> > > -void xe_device_declare_wedged(struct xe_device *xe)
> > > +void xe_device_declare_wedged(struct xe_device *xe, char **event_params)
> > >  {
> > >  	struct xe_gt *gt;
> > >  	u8 id;
> > > @@ -984,12 +987,17 @@ void xe_device_declare_wedged(struct xe_device *xe)
> > >  	xe_pm_runtime_get_noresume(xe);
> > >  
> > >  	if (!atomic_xchg(&xe->wedged.flag, 1)) {
> > > +		struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> > > +
> > >  		xe->needs_flr_on_fini = true;
> > >  		drm_err(&xe->drm,
> > >  			"CRITICAL: Xe has declared device %s as wedged.\n"
> > >  			"IOCTLs and executions are blocked. Only a rebind may clear the failure\n"
> > >  			"Please file a _new_ bug report at https://gitlab.freedesktop.org/drm/xe/kernel/issues/new\n",
> > >  			dev_name(xe->drm.dev));
> > > +
> > > +		/* Notify userspace about reset required */
> > > +		kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, event_params);
> > >  	}
> > >  
> > >  	for_each_gt(gt, xe, id)
> > > diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> > > index db6cc8d0d6b8..5d40fc6f0904 100644
> > > --- a/drivers/gpu/drm/xe/xe_device.h
> > > +++ b/drivers/gpu/drm/xe/xe_device.h
> > > @@ -174,7 +174,7 @@ static inline bool xe_device_wedged(struct xe_device *xe)
> > >  	return atomic_read(&xe->wedged.flag);
> > >  }
> > >  
> > > -void xe_device_declare_wedged(struct xe_device *xe);
> > > +void xe_device_declare_wedged(struct xe_device *xe, char **reset_event);
> > >  
> > >  struct xe_file *xe_file_get(struct xe_file *xef);
> > >  void xe_file_put(struct xe_file *xef);
> > > diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
> > > index 58895ed22f6e..519f3c2cf9e2 100644
> > > --- a/drivers/gpu/drm/xe/xe_gt.c
> > > +++ b/drivers/gpu/drm/xe/xe_gt.c
> > > @@ -741,6 +741,24 @@ static int do_gt_restart(struct xe_gt *gt)
> > >  	return 0;
> > >  }
> > >  
> > > +static void xe_gt_reset_failed(struct xe_gt *gt, int err)
> > > +{
> > > +	char *event_params[5];
> > > +
> > > +	xe_gt_err(gt, "reset failed (%pe)\n", ERR_PTR(err));
> > > +
> > > +	event_params[0] = DRM_XE_RESET_REQUIRED_UEVENT;
> > > +	event_params[1] = DRM_XE_RESET_REQUIRED_UEVENT_REASON_GT;
> > > +	event_params[2] = kasprintf(GFP_KERNEL, "TILE_ID=%d", gt_to_tile(gt)->id);
> > > +	event_params[3] = kasprintf(GFP_KERNEL, "GT_ID=%d", gt->info.id);
> > 
> > the TILE_ID and GT_ID can be passed for other events as well, with that you can
> > have a common function to send uevent which would take reason as an input.
> 
> But is that required for all cases? There could be potential cases atleast
> in the future where it is not needed.
> 
> > > +	event_params[4] = NULL;
> > > +
> > > +	xe_device_declare_wedged(gt_to_xe(gt), event_params);
> > > +
> > > +	kfree(event_params[2]);
> > > +	kfree(event_params[3]);
> > > +}
> > > +
> > >  static int gt_reset(struct xe_gt *gt)
> > >  {
> > >  	int err;
> > > @@ -796,10 +814,7 @@ static int gt_reset(struct xe_gt *gt)
> > >  	XE_WARN_ON(xe_uc_start(&gt->uc));
> > >  	xe_pm_runtime_put(gt_to_xe(gt));
> > >  err_fail:
> > > -	xe_gt_err(gt, "reset failed (%pe)\n", ERR_PTR(err));
> > > -
> > > -	xe_device_declare_wedged(gt_to_xe(gt));
> > > -
> > > +	xe_gt_reset_failed(gt, err);
> > >  	return err;
> > >  }
> > >  
> > > diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> > > index de0fe9e65746..b544012f5b11 100644
> > > --- a/drivers/gpu/drm/xe/xe_guc.c
> > > +++ b/drivers/gpu/drm/xe/xe_guc.c
> > > @@ -560,6 +560,17 @@ static s32 guc_pc_get_cur_freq(struct xe_guc_pc *guc_pc)
> > >  	return ret ? ret : freq;
> > >  }
> > >  
> > > +static void xe_guc_load_failed(struct xe_gt *gt)
> > > +{
> > > +	char *event_params[3];
> > > +
> > > +	event_params[0] = DRM_XE_RESET_REQUIRED_UEVENT;
> > > +	event_params[1] = DRM_XE_RESET_REQUIRED_UEVENT_REASON_GUC;
> > > +	event_params[2] = NULL;
> > > +
> > > +	xe_device_declare_wedged(gt_to_xe(gt), event_params);
> > > +}
> > > +
> > >  /*
> > >   * Wait for the GuC to start up.
> > >   *
> > > @@ -684,7 +695,7 @@ static void guc_wait_ucode(struct xe_guc *guc)
> > >  			break;
> > >  		}
> > >  
> > > -		xe_device_declare_wedged(gt_to_xe(gt));
> > > +		xe_guc_load_failed(gt);
> > >  	} else if (delta_ms > GUC_LOAD_TIME_WARN_MS) {
> > >  		xe_gt_warn(gt, "excessive init time: %lldms! [status = 0x%08X, timeouts = %d]\n",
> > >  			   delta_ms, status, count);
> > > diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
> > > index 460808507947..33ed6221f465 100644
> > > --- a/drivers/gpu/drm/xe/xe_guc_submit.c
> > > +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
> > > @@ -891,6 +891,17 @@ void xe_guc_submit_wedge(struct xe_guc *guc)
> > >  	mutex_unlock(&guc->submission_state.lock);
> > >  }
> > >  
> > > +static void xe_exec_queue_timedout(struct xe_device *xe)
> > > +{
> > > +	char *event_params[3];
> > > +
> > > +	event_params[0] = DRM_XE_RESET_REQUIRED_UEVENT;
> > > +	event_params[1] = DRM_XE_RESET_REQUIRED_UEVENT_REASON_TOUT;
> > > +	event_params[2] = NULL;
> > > +
> > > +	xe_device_declare_wedged(xe, event_params);
> > > +}
> > > +
> > >  static bool guc_submit_hint_wedged(struct xe_guc *guc)
> > >  {
> > >  	struct xe_device *xe = guc_to_xe(guc);
> > > @@ -901,7 +912,7 @@ static bool guc_submit_hint_wedged(struct xe_guc *guc)
> > >  	if (xe_device_wedged(xe))
> > >  		return true;
> > >  
> > 
> > i see that this is even called from xe_guc_exec_queue_lr_cleanup which is for long running queue
> > from various call paths need to check in what scenarios those happen.
> 
> Should we add a reason for long running queue?

Both of your questions would probably be answered if this was getting developed
at the same time of the user space usage of these uevents.

> 
> Raag