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

[Raag Jadav <raag.jadav@intel.com>]

On Wed, Aug 14, 2024 at 12:16:41PM +0530, Aravind Iddamsetty wrote:
>
>On 13/08/24 22:24, Rodrigo Vivi wrote:
>> 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.
> 
> 
> At least in these cases it makes sense as they (other reasons)
> can be associated to a GT and a Tile. If in future they arises a
> reason where these details are not needed i guess we can handle that.

But then we'll have to modify it with every new addition, which doesn't
look like a win. With current implementation the callers atleast have
the autonomy to send params as-needed.

Raag