Re: [Patch v2] drm/amdkfd: Fix CRIU restore op due to doorbell offset

[Felix Kuehling]

On 2022-09-07 15:43, Rajneesh Bhardwaj wrote:

Recently introduced change to allocate doorbells only when the first
queue is created or mapped for CPU / GPU access, did not consider
Checkpoint Restore scenario completely. This fix allows the CRIU restore
operation by extending the doorbell optimization to CRIU restore
scenario.

Fixes: 'commit 15bcfbc55b57 ("drm/amdkfd: Allocate doorbells only when needed")'

Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhard...@amd.com>

Reviewed-by: Felix Kuehling <felix.kuehl...@amd.com>

Thanks!

---

Changes in v2:

* Addressed review feedback from Felix

  drivers/gpu/drm/amd/amdkfd/kfd_chardev.c               | 6 ++++++
  drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c              | 3 +++
  drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c | 7 +++++++
  3 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 84da1a9ce37c..56f7307c21d2 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -2153,6 +2153,12 @@ static int criu_restore_devices(struct kfd_process *p,
                        ret = PTR_ERR(pdd);
                        goto exit;
                }
+
+               if (!pdd->doorbell_index &&
+                   kfd_alloc_process_doorbells(pdd->dev, &pdd->doorbell_index) 
< 0) {
+                       ret = -ENOMEM;
+                       goto exit;
+               }
        }

/*

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
index b33798f89ef0..cd4e61bf0493 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
@@ -303,6 +303,9 @@ int kfd_alloc_process_doorbells(struct kfd_dev *kfd, 
unsigned int *doorbell_inde
        if (r > 0)
                *doorbell_index = r;

+ if (r < 0)

+               pr_err("Failed to allocate process doorbells\n");
+
        return r;
  }

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c

index 6e3e7f54381b..5137476ec18e 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
@@ -857,6 +857,13 @@ int kfd_criu_restore_queue(struct kfd_process *p,
                ret = -EINVAL;
                goto exit;
        }
+
+       if (!pdd->doorbell_index &&
+           kfd_alloc_process_doorbells(pdd->dev, &pdd->doorbell_index) < 0) {
+               ret = -ENOMEM;
+               goto exit;
+       }
+
        /* data stored in this order: mqd, ctl_stack */
        mqd = q_extra_data;
        ctl_stack = mqd + q_data->mqd_size;