[PATCH] drm/amdgpu: Unmap CSA under SR-IOV in KFD path

[Christian König]

Well that is exactly what we already do here. The only problem is we do 
the wrong check amdgpu_vm_make_compute().

Instead of checking if some page tables are already filled we check if 
some mapping is already made.

Regards,
Christian.

Am 30.04.19 um 01:34 schrieb Kuehling, Felix:
> I remember a past discussion to change the CSA allocation/mapping scheme
> to avoid this issue in the first place. Can adding the CSA to the VM be
> delayed a little to a point after the VM gets converted to a compute VM?
> Maybe the first command submission?
>
> Regards,
>     Felix
>
> On 2019-04-28 6:25 a.m., Trigger Huang wrote:
>> In amdgpu open path, CSA will be mappened in VM, so when opening
>> KFD, calling mdgpu_vm_make_compute  will fail because it found this
>> VM is not a clean VM with some mappings, as a result, it will lead
>> to failed to create process VM object
>>
>> The fix is try to unmap CSA, and actually CSA is not needed in
>> compute VF world switch
>>
>> Signed-off-by: Trigger Huang <Trigger.Huang at amd.com>
>> ---
>>    drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 10 ++++++++++
>>    drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c          |  2 +-
>>    2 files changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> index 697b8ef..e0bc457 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> @@ -956,6 +956,16 @@ int amdgpu_amdkfd_gpuvm_acquire_process_vm(struct kgd_dev *kgd,
>>    	if (avm->process_info)
>>    		return -EINVAL;
>>    
>> +	/* Delete CSA mapping to make sure this VM is a clean VM  before
>> +	 *  converting VM
>> +	 */
>> +	if (amdgpu_sriov_vf(adev) && drv_priv->csa_va) {
>> +		amdgpu_bo_reserve(adev->virt.csa_obj, true);
>> +		amdgpu_vm_bo_rmv(adev, drv_priv->csa_va);
>> +		drv_priv->csa_va = NULL;
>> +		amdgpu_bo_unreserve(adev->virt.csa_obj);
>> +	}
>> +
>>    	/* Convert VM into a compute VM */
>>    	ret = amdgpu_vm_make_compute(adev, avm, pasid);
>>    	if (ret)
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> index da7b4fe..361c2e5 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>> @@ -1069,7 +1069,7 @@ void amdgpu_driver_postclose_kms(struct drm_device *dev,
>>    
>>    	amdgpu_vm_bo_rmv(adev, fpriv->prt_va);
>>    
>> -	if (amdgpu_sriov_vf(adev)) {
>> +	if (amdgpu_sriov_vf(adev) && fpriv->csa_va) {
>>    		/* TODO: how to handle reserve failure */
>>    		BUG_ON(amdgpu_bo_reserve(adev->virt.csa_obj, true));
>>    		amdgpu_vm_bo_rmv(adev, fpriv->csa_va);
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