[PATCH] drm/amdgpu: Update SPM_VMID with the job's vmid when application reserves the vmid

[Christian König]

Am 02.03.20 um 06:35 schrieb Jacob He:
> SPM access the video memory according to SPM_VMID. It should be updated
> with the job's vmid right before the job is scheduled. SPM_VMID is a
> global resource
>
> Change-Id: Id3881908960398f87e7c95026a54ff83ff826700
> Signed-off-by: Jacob He <jacob.he at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index c00696f3017e..c761d3a0b6e8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -1080,8 +1080,12 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
>   	struct dma_fence *fence = NULL;
>   	bool pasid_mapping_needed = false;
>   	unsigned patch_offset = 0;
> +	bool update_spm_vmid_needed = (job->vm && (job->vm->reserved_vmid[vmhub] != NULL));
>   	int r;
>   
> +	if (update_spm_vmid_needed && adev->gfx.rlc.funcs->update_spm_vmid)
> +		adev->gfx.rlc.funcs->update_spm_vmid(adev, job->vmid);
> +

It would be better if we could do that asynchronously with a register 
write on the ring.

The alternative is that we block for the VM to be idle in 
amdgpu_vm_ioctl() before unreserving the VMID.

In other words lock the reservation object of the root PD and call 
amdgpu_vm_wait_idle() before calling amdgpu_vmid_free_reserved().

Regards,
Christian.

>   	if (amdgpu_vmid_had_gpu_reset(adev, id)) {
>   		gds_switch_needed = true;
>   		vm_flush_needed = true;