From 124150d3e944089768e66ec05988a74a136a4a6b Mon Sep 17 00:00:00 2001
From: David Yat Sin <david.yatsin@amd.com>
Date: Mon, 16 Aug 2021 10:39:39 -0400
Subject: drm/amdkfd: CRIU Implement KFD unpause operation
Git-commit: cd9f79103003599e58f9f394c07cb4045883a51e
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Introducing UNPAUSE op. After CRIU amdgpu plugin performs a PROCESS_INFO
op the queues will be stay in an evicted state. Once the plugin is done
draining BO contents, it is safe to perform an UNPAUSE op for the queues
to resume.

Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: David Yat Sin <david.yatsin@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 37 +++++++++++++++++++++++-
 drivers/gpu/drm/amd/amdkfd/kfd_priv.h    |  2 ++
 drivers/gpu/drm/amd/amdkfd/kfd_process.c |  1 +
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 95fc5668195c..6af6deeda523 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -2049,6 +2049,14 @@ static int criu_checkpoint(struct file *filep,
 		goto exit_unlock;
 	}
 
+	/* Confirm all process queues are evicted */
+	if (!p->queues_paused) {
+		pr_err("Cannot dump process when queues are not in evicted state\n");
+		/* CRIU plugin did not call op PROCESS_INFO before checkpointing */
+		ret = -EINVAL;
+		goto exit_unlock;
+	}
+
 	criu_get_process_object_info(p, &num_bos, &priv_size);
 
 	if (num_bos != args->num_bos ||
@@ -2388,7 +2396,24 @@ static int criu_unpause(struct file *filep,
 			struct kfd_process *p,
 			struct kfd_ioctl_criu_args *args)
 {
-	return 0;
+	int ret;
+
+	mutex_lock(&p->mutex);
+
+	if (!p->queues_paused) {
+		mutex_unlock(&p->mutex);
+		return -EINVAL;
+	}
+
+	ret = kfd_process_restore_queues(p);
+	if (ret)
+		pr_err("Failed to unpause queues ret:%d\n", ret);
+	else
+		p->queues_paused = false;
+
+	mutex_unlock(&p->mutex);
+
+	return ret;
 }
 
 static int criu_resume(struct file *filep,
@@ -2440,6 +2465,12 @@ static int criu_process_info(struct file *filep,
 		goto err_unlock;
 	}
 
+	ret = kfd_process_evict_queues(p);
+	if (ret)
+		goto err_unlock;
+
+	p->queues_paused = true;
+
 	args->pid = task_pid_nr_ns(p->lead_thread,
 					task_active_pid_ns(p->lead_thread));
 
@@ -2447,6 +2478,10 @@ static int criu_process_info(struct file *filep,
 
 	dev_dbg(kfd_device, "Num of bos:%u\n", args->num_bos);
 err_unlock:
+	if (ret) {
+		kfd_process_restore_queues(p);
+		p->queues_paused = false;
+	}
 	mutex_unlock(&p->mutex);
 	return ret;
 }
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index b79970f252ae..64abb19565be 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -878,6 +878,8 @@ struct kfd_process {
 	bool xnack_enabled;
 
 	atomic_t poison;
+	/* Queues are in paused stated because we are in the process of doing a CRIU checkpoint */
+	bool queues_paused;
 };
 
 #define KFD_PROCESS_TABLE_SIZE 5 /* bits: 32 entries */
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index b3198e186622..0649064b8e95 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -1384,6 +1384,7 @@ static struct kfd_process *create_process(const struct task_struct *thread)
 	process->mm = thread->mm;
 	process->lead_thread = thread->group_leader;
 	process->n_pdds = 0;
+	process->queues_paused = false;
 	INIT_DELAYED_WORK(&process->eviction_work, evict_process_worker);
 	INIT_DELAYED_WORK(&process->restore_work, restore_process_worker);
 	process->last_restore_timestamp = get_jiffies_64();
-- 
2.38.1