[PATCH] drm/amdgpu: Make sure to reserve BOs before adding or removing

[Errabolu, Ramesh]

Kent, the call to map has the same structure. Is it not possible to call kfd_mem_attach after BO's are reserved?

Regards,
Ramesh

-----Original Message-----
From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of Felix Kuehling
Sent: Monday, November 1, 2021 3:18 PM
To: Russell, Kent <Kent.Russell at amd.com>; amd-gfx at lists.freedesktop.org
Subject: Re: [PATCH] drm/amdgpu: Make sure to reserve BOs before adding or removing

[CAUTION: External Email]

Am 2021-11-01 um 4:14 p.m. schrieb Kent Russell:
> BOs need to be reserved before they are added or removed, so ensure 
> that they are reserved during kfd_mem_attach and kfd_mem_detach
>
> Signed-off-by: Kent Russell <kent.russell at amd.com>

Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>


> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> index 61784bbfd7fd..8d30ccd70800 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> @@ -798,14 +798,19 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
>               }
>
>               /* Add BO to VM internal data structures */
> +             ret = amdgpu_bo_reserve(bo[i], false);
> +             if (ret) {
> +                     pr_debug("Unable to reserve BO during memory attach");
> +                     goto unwind;
> +             }
>               attachment[i]->bo_va = amdgpu_vm_bo_add(adev, vm, 
> bo[i]);
> +             amdgpu_bo_unreserve(bo[i]);
>               if (unlikely(!attachment[i]->bo_va)) {
>                       ret = -ENOMEM;
>                       pr_err("Failed to add BO object to VM. ret == %d\n",
>                              ret);
>                       goto unwind;
>               }
> -
>               attachment[i]->va = va;
>               attachment[i]->pte_flags = get_pte_flags(adev, mem);
>               attachment[i]->adev = adev; @@ -821,7 +826,9 @@ static 
> int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
>               if (!attachment[i])
>                       continue;
>               if (attachment[i]->bo_va) {
> +                     amdgpu_bo_reserve(bo[i], true);
>                       amdgpu_vm_bo_rmv(adev, attachment[i]->bo_va);
> +                     amdgpu_bo_unreserve(bo[i]);
>                       list_del(&attachment[i]->list);
>               }
>               if (bo[i])
> @@ -1700,12 +1707,12 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
>       pr_debug("Release VA 0x%llx - 0x%llx\n", mem->va,
>               mem->va + bo_size * (1 + mem->aql_queue));
>
> -     ret = unreserve_bo_and_vms(&ctx, false, false);
> -
>       /* Remove from VM internal data structures */
>       list_for_each_entry_safe(entry, tmp, &mem->attachments, list)
>               kfd_mem_detach(entry);
>
> +     ret = unreserve_bo_and_vms(&ctx, false, false);
> +
>       /* Free the sync object */
>       amdgpu_sync_free(&mem->sync);
>