[PATCH v3 1/7] drm/amdgpu: update XGMI physical node id and GMC configs on resume

Sam guoqzhan at amd.com
Wed May 7 11:03:23 UTC 2025


On 2025/5/7 18:03, Lazar, Lijo wrote:
> On 5/7/2025 11:52 AM, Zhang, GuoQing (Sam) wrote:
>> [AMD Official Use Only - AMD Internal Distribution Only]
>>
>>
>>   
>>
>>> Please keep in mind that this is not the only scenario addressed by the
>>> driver - for ex: a resume sequence is executed after a device reset.
>>> This patch itself introduces unwanted sequences for other commonly used
>>> usecases. Please rework on the series without breaking existing usecases.
>>> Thanks,
>>> Lijo
>>   
>>
>> Hi @Lazar, Lijo<mailto:Lijo.Lazar at amd.com>, Thank you for the feedback.
>>
>>   
>>
>> I also think the new code should be inside a check so that new code is
>> executed only on resume with different VF and do not break existing
>> usecases. Following is the implementation of this approach I can think of.
>>
>> - introduce new field `prev_physical_node_id ` in `struct amdgpu_xgmi `.
>> update the fields on resume.
>>
>> - put new code inside code block `if (prev_physical_node_id  !=
>> physical_node_id )`
>>
>>
> Can this happen only with XGMI under this condition? Any other method
> possible like preparing a 'unique signature' and matching it to identify
> if it resumed on an identically configured system?

Yes, this hibernate-resume with different VF feature is only for devices 
with XGMI. Detecting XGMI node id change is the only way I can think of 
to identify the case. It's also a very simple way.

@Koenig, Christian <mailto:Christian.Koenig at amd.com> Are you OK with 
this approach, adding a check for the new code sequence?

> Regardless, instead of having a direct check, better to wrap it inside
> something like
> 	if (amdgpu_virt_need_migration()) or something more appropriate.

Yes, I will do that. Thank you!

Regards
Sam

>   
> Thanks,
> Lijo
>
>> Is this approach acceptable? If not, can you suggest a better approach?
>> @Lazar, Lijo<mailto:Lijo.Lazar at amd.com> @Koenig, Christian
>> <mailto:Christian.Koenig at amd.com> Thank you!
>>
>>   
>>
>> Regards
>>
>> Sam
>>
>>   
>>
>> *From: *Lazar, Lijo<Lijo.Lazar at amd.com>
>> *Date: *Tuesday, May 6, 2025 at 19:55
>> *To: *Zhang, GuoQing (Sam)<GuoQing.Zhang at amd.com>, amd-
>> gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>
>> *Cc: *Zhao, Victor<Victor.Zhao at amd.com>, Chang, HaiJun
>> <HaiJun.Chang at amd.com>, Koenig, Christian<Christian.Koenig at amd.com>,
>> Deucher, Alexander<Alexander.Deucher at amd.com>, Zhang, Owen(SRDC)
>> <Owen.Zhang2 at amd.com>, Ma, Qing (Mark)<Qing.Ma at amd.com>, Jiang Liu
>> <gerry at linux.alibaba.com>
>> *Subject: *Re: [PATCH v3 1/7] drm/amdgpu: update XGMI physical node id
>> and GMC configs on resume
>>
>>
>>
>> On 5/6/2025 3:06 PM, Samuel Zhang wrote:
>>> For virtual machine with vGPUs in SRIOV single device mode and XGMI
>>> is enabled, XGMI physical node ids may change when waking up from
>>> hiberation with different vGPU devices. So update XGMI physical node
>>> ids on resume.
>>>
>> Please keep in mind that this is not the only scenario addressed by the
>> driver - for ex: a resume sequence is executed after a device reset.
>> This patch itself introduces unwanted sequences for other commonly used
>> usecases. Please rework on the series without breaking existing usecases.
>>
>> Thanks,
>> Lijo
>>
>>> Update GPU memory controller configuration on resume if XGMI physical
>>> node ids are changed.
>>>
>>> Signed-off-by: Jiang Liu<gerry at linux.alibaba.com>
>>> Signed-off-by: Samuel Zhang<guoqing.zhang at amd.com>
>>> ---
>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 24 ++++++++++++++++++++++
>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c    |  3 +--
>>>    drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c      |  4 ++++
>>>    3 files changed, 29 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/
>> drm/amd/amdgpu/amdgpu_device.c
>>> index d477a901af84..e795af5067e5 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -5040,6 +5040,27 @@ int amdgpu_device_suspend(struct drm_device
>> *dev, bool notify_clients)
>>>          return 0;
>>>    }
>>>   
>>> +static int amdgpu_device_update_xgmi_info(struct amdgpu_device *adev)
>>> +{
>>> +     int r;
>>> +     unsigned int prev_physical_node_id;
>>> +
>>> +     /* Get xgmi info again for sriov to detect device changes */
>>> +     if (amdgpu_sriov_vf(adev) &&
>>> +         !(adev->flags & AMD_IS_APU) &&
>>> +         adev->gmc.xgmi.supported &&
>>> +         !adev->gmc.xgmi.connected_to_cpu) {
>>> +             prev_physical_node_id = adev->gmc.xgmi.physical_node_id;
>>> +             r = adev->gfxhub.funcs->get_xgmi_info(adev);
>>> +             if (r)
>>> +                     return r;
>>> +
>>> +             dev_info(adev->dev, "xgmi node, old id %d, new id %d\n",
>>> +                     prev_physical_node_id, adev-
>>> gmc.xgmi.physical_node_id);
>>> +     }
>>> +     return 0;
>>> +}
>>> +
>>>    /**
>>>     * amdgpu_device_resume - initiate device resume
>>>     *
>>> @@ -5059,6 +5080,9 @@ int amdgpu_device_resume(struct drm_device *dev,
>> bool notify_clients)
>>>                  r = amdgpu_virt_request_full_gpu(adev, true);
>>>                  if (r)
>>>                          return r;
>>> +             r = amdgpu_device_update_xgmi_info(adev);
>>> +             if (r)
>>> +                     return r;
>>>          }
>>>   
>>>          if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/
>> drm/amd/amdgpu/amdgpu_gmc.c
>>> index d1fa5e8e3937..a2abddf3c110 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
>>> @@ -1298,8 +1298,7 @@ int amdgpu_gmc_get_nps_memranges(struct
>> amdgpu_device *adev,
>>>          if (!mem_ranges || !exp_ranges)
>>>                  return -EINVAL;
>>>   
>>> -     refresh = (adev->init_lvl->level !=
>> AMDGPU_INIT_LEVEL_MINIMAL_XGMI) &&
>>> -               (adev->gmc.reset_flags & AMDGPU_GMC_INIT_RESET_NPS);
>>> +     refresh = true;
>>>          ret = amdgpu_discovery_get_nps_info(adev, &nps_type, &ranges,
>>>                                              &range_cnt, refresh);
>>>   
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/
>> amd/amdgpu/gmc_v9_0.c
>>> index 59385da80185..1eb451a3743b 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
>>> @@ -2533,6 +2533,10 @@ static int gmc_v9_0_resume(struct
>> amdgpu_ip_block *ip_block)
>>>          struct amdgpu_device *adev = ip_block->adev;
>>>          int r;
>>>   
>>> +     r = gmc_v9_0_mc_init(adev);
>>> +     if (r)
>>> +             return r;
>>> +
>>>          /* If a reset is done for NPS mode switch, read the memory range
>>>           * information again.
>>>           */


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