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

Christian König christian.koenig at amd.com
Wed May 7 12:21:48 UTC 2025


On 5/7/25 13:03, Sam wrote:
> 
> 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?


Well you still need to avoid calling gmc_v9_0_mc_init() since that is most likely incorrect.

Regards,
Christian.

> 
>> 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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