drm/amdkfd: CRIU resume shared virtual memory ranges

In CRIU resume stage, resume all the shared virtual memory ranges from
the data stored inside the resuming kfd process during CRIU restore
phase. Also setup xnack mode and free up the resources.

KFD_IOCTL_SVM_ATTR_CLR_FLAGS is not available for querying via get_attr
interface but we must clear the flags during restore as there might be
some default flags set when the prange is created. Also handle the
invalid PREFETCH atribute values saved during checkpoint by replacing
them with another dummy KFD_IOCTL_SVM_ATTR_SET_FLAGS attribute.

(rajneesh: Fixed the checkpatch reported problems)
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 41ac049b3316..41f03d165bad 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -3487,6 +3487,109 @@ fill_values:
 	return 0;
 }
 
+int kfd_criu_resume_svm(struct kfd_process *p)
+{
+	struct kfd_ioctl_svm_attribute *set_attr_new, *set_attr = NULL;
+	int nattr_common = 4, nattr_accessibility = 1;
+	struct criu_svm_metadata *criu_svm_md = NULL;
+	struct svm_range_list *svms = &p->svms;
+	struct criu_svm_metadata *next = NULL;
+	uint32_t set_flags = 0xffffffff;
+	int i, j, num_attrs, ret = 0;
+	uint64_t set_attr_size;
+	struct mm_struct *mm;
+
+	if (list_empty(&svms->criu_svm_metadata_list)) {
+		pr_debug("No SVM data from CRIU restore stage 2\n");
+		return ret;
+	}
+
+	mm = get_task_mm(p->lead_thread);
+	if (!mm) {
+		pr_err("failed to get mm for the target process\n");
+		return -ESRCH;
+	}
+
+	num_attrs = nattr_common + (nattr_accessibility * p->n_pdds);
+
+	i = j = 0;
+	list_for_each_entry(criu_svm_md, &svms->criu_svm_metadata_list, list) {
+		pr_debug("criu_svm_md[%d]\n\tstart: 0x%llx size: 0x%llx (npages)\n",
+			 i, criu_svm_md->data.start_addr, criu_svm_md->data.size);
+
+		for (j = 0; j < num_attrs; j++) {
+			pr_debug("\ncriu_svm_md[%d]->attrs[%d].type : 0x%x \ncriu_svm_md[%d]->attrs[%d].value : 0x%x\n",
+				 i, j, criu_svm_md->data.attrs[j].type,
+				 i, j, criu_svm_md->data.attrs[j].value);
+			switch (criu_svm_md->data.attrs[j].type) {
+			/* During Checkpoint operation, the query for
+			 * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC attribute might
+			 * return KFD_IOCTL_SVM_LOCATION_UNDEFINED if they were
+			 * not used by the range which was checkpointed. Care
+			 * must be taken to not restore with an invalid value
+			 * otherwise the gpuidx value will be invalid and
+			 * set_attr would eventually fail so just replace those
+			 * with another dummy attribute such as
+			 * KFD_IOCTL_SVM_ATTR_SET_FLAGS.
+			 */
+			case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
+				if (criu_svm_md->data.attrs[j].value ==
+				    KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
+					criu_svm_md->data.attrs[j].type =
+						KFD_IOCTL_SVM_ATTR_SET_FLAGS;
+					criu_svm_md->data.attrs[j].value = 0;
+				}
+				break;
+			case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
+				set_flags = criu_svm_md->data.attrs[j].value;
+				break;
+			default:
+				break;
+			}
+		}
+
+		/* CLR_FLAGS is not available via get_attr during checkpoint but
+		 * it needs to be inserted before restoring the ranges so
+		 * allocate extra space for it before calling set_attr
+		 */
+		set_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
+						(num_attrs + 1);
+		set_attr_new = krealloc(set_attr, set_attr_size,
+					    GFP_KERNEL);
+		if (!set_attr_new) {
+			ret = -ENOMEM;
+			goto exit;
+		}
+		set_attr = set_attr_new;
+
+		memcpy(set_attr, criu_svm_md->data.attrs, num_attrs *
+					sizeof(struct kfd_ioctl_svm_attribute));
+		set_attr[num_attrs].type = KFD_IOCTL_SVM_ATTR_CLR_FLAGS;
+		set_attr[num_attrs].value = ~set_flags;
+
+		ret = svm_range_set_attr(p, mm, criu_svm_md->data.start_addr,
+					 criu_svm_md->data.size, num_attrs + 1,
+					 set_attr);
+		if (ret) {
+			pr_err("CRIU: failed to set range attributes\n");
+			goto exit;
+		}
+
+		i++;
+	}
+exit:
+	kfree(set_attr);
+	list_for_each_entry_safe(criu_svm_md, next, &svms->criu_svm_metadata_list, list) {
+		pr_debug("freeing criu_svm_md[]\n\tstart: 0x%llx\n",
+						criu_svm_md->data.start_addr);
+		kfree(criu_svm_md);
+	}
+
+	mmput(mm);
+	return ret;
+
+}
+
 int kfd_criu_restore_svm(struct kfd_process *p,
 			 uint8_t __user *user_priv_ptr,
 			 uint64_t *priv_data_offset,