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

[Ghimiray, Himal Prasad]

Hi Rodrigo,

On 26-07-2023 20:09, Rodrigo Vivi wrote:
> 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
> ?

Please find the output from udevadm  monitor below


KERNEL[471.352287] change 
/devices/pci0000:89/0000:89:02.0/0000:8a:00.0/0000:8b:01.0/0000:8c:00.0 
(pci)
ACTION=change
DEVPATH=/devices/pci0000:89/0000:89:02.0/0000:8a:00.0/0000:8b:01.0/0000:8c:00.0
SUBSYSTEM=pci
DEVICE_STATUS=NEEDS_RESET
RESET_FAILED=gt
RESET_ID=0
DRIVER=xe
PCI_CLASS=38000
PCI_ID=8086:0BD6
PCI_SUBSYS_ID=8086:0000
PCI_SLOT_NAME=0000:8c:00.0
MODALIAS=pci:v00008086d00000BD6sv00008086sd00000000bc03sc80i00
SEQNUM=8817

BR

Himal


>
>> +
>> +	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
>>