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

Lazar, Lijo lijo.lazar at amd.com
Wed May 7 10:03:15 UTC 2025



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?

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