drm/amdkfd: CRIU export dmabuf handles for GTT BOs

Export dmabuf handles for GTT BOs so that their contents can be accessed
using SDMA during checkpoint/restore.

v2: Squash in fix from David to set dmabuf handle to invalid for BOs
that cannot be accessed using SDMA during checkpoint/restore.
Signed-off-by: David Yat Sin <david.yatsin@amd.com>
Reviewed-by : Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

@@ -1759,14 +1759,18 @@ static int criu_checkpoint_bos(struct kfd_process *p,
 					goto exit;
 				}
 			}
-			if (bo_bucket->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) {
+			if (bo_bucket->alloc_flags
+			    & (KFD_IOC_ALLOC_MEM_FLAGS_VRAM | KFD_IOC_ALLOC_MEM_FLAGS_GTT)) {
 				ret = criu_get_prime_handle(&dumper_bo->tbo.base,
 						bo_bucket->alloc_flags &
 						KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ? DRM_RDWR : 0,
 						&bo_bucket->dmabuf_fd);
 				if (ret)
 					goto exit;
+			} else {
+				bo_bucket->dmabuf_fd = KFD_INVALID_FD;
 			}
+
 			if (bo_bucket->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL)
 				bo_bucket->offset = KFD_MMAP_TYPE_DOORBELL |
 					KFD_MMAP_GPU_ID(pdd->dev->id);
@@ -1812,7 +1816,8 @@ static int criu_checkpoint_bos(struct kfd_process *p,
 
 exit:
 	while (ret && bo_index--) {
-		if (bo_buckets[bo_index].alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_VRAM)
+		if (bo_buckets[bo_index].alloc_flags
+		    & (KFD_IOC_ALLOC_MEM_FLAGS_VRAM | KFD_IOC_ALLOC_MEM_FLAGS_GTT))
 			close_fd(bo_buckets[bo_index].dmabuf_fd);
 	}
 
@@ -2211,12 +2216,16 @@ static int criu_restore_bo(struct kfd_process *p,
 
 	pr_debug("map memory was successful for the BO\n");
 	/* create the dmabuf object and export the bo */
-	if (bo_bucket->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) {
+	if (bo_bucket->alloc_flags
+	    & (KFD_IOC_ALLOC_MEM_FLAGS_VRAM | KFD_IOC_ALLOC_MEM_FLAGS_GTT)) {
 		ret = criu_get_prime_handle(&kgd_mem->bo->tbo.base, DRM_RDWR,
 					    &bo_bucket->dmabuf_fd);
 		if (ret)
 			return ret;
+	} else {
+		bo_bucket->dmabuf_fd = KFD_INVALID_FD;
 	}
+
 	return 0;
 }
 
@@ -2281,7 +2290,8 @@ static int criu_restore_bos(struct kfd_process *p,
 
 exit:
 	while (ret && i--) {
-		if (bo_buckets[i].alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_VRAM)
+		if (bo_buckets[i].alloc_flags
+		   & (KFD_IOC_ALLOC_MEM_FLAGS_VRAM | KFD_IOC_ALLOC_MEM_FLAGS_GTT))
 			close_fd(bo_buckets[i].dmabuf_fd);
 	}
 	kvfree(bo_buckets);

include/uapi/linux/kfd_ioctl.h

@@ -33,9 +33,10 @@
  * - 1.5 - Add SVM API
  * - 1.6 - Query clear flags in SVM get_attr API
  * - 1.7 - Checkpoint Restore (CRIU) API
+ * - 1.8 - CRIU - Support for SDMA transfers with GTT BOs
  */
 #define KFD_IOCTL_MAJOR_VERSION 1
-#define KFD_IOCTL_MINOR_VERSION 7
+#define KFD_IOCTL_MINOR_VERSION 8
 
 struct kfd_ioctl_get_version_args {
 	__u32 major_version;	/* from KFD */
@@ -195,6 +196,8 @@ struct kfd_ioctl_dbg_wave_control_args {
 	__u32 buf_size_in_bytes;	/*including gpu_id and buf_size */
 };
 
+#define KFD_INVALID_FD     0xffffffff
+
 /* Matching HSA_EVENTTYPE */
 #define KFD_IOC_EVENT_SIGNAL			0
 #define KFD_IOC_EVENT_NODECHANGE		1