xen-dom-mgmt: rework return value handling for dom0 initcall

Some return codes in dom0 initcall were ignored. Also return value
from initcall was improper (positive integer from last call, when
Zephyr initcall expects it to be 0 in success case).
Add error handling in initcall and add proper return value xs_init_root
to return proper result to initcall instead of just 0.

Signed-off-by: Dmytro Firsov <[email protected]>

xen-dom-mgmt/src/xen-dom-mgmt.c

@@ -945,10 +945,21 @@ static int init_domain0(const struct device *d)
 	dom0->max_mem_kb = 0;
 #endif
 
-	xs_init_root();
-	xss_write("/tool/xenstored", "");
-	xs_initialize_xenstore(0, dom0);
+	ret = xs_init_root();
+	if (ret) {
+		LOG_ERR("Failed to init Xenstore root node");
+		goto out;
+	}
 
+	ret = xss_write("/tool/xenstored", "");
+	if (ret) {
+		LOG_ERR("Failed to create /tool/xenstored node, err = %d", ret);
+	}
+
+	ret = xs_initialize_xenstore(0, dom0);
+	if (ret) {
+		LOG_ERR("Failed to add Domain-0 xenstore entries, err = %d", ret);
+	}
 out:
 #ifdef CONFIG_XSTAT
 	k_free(dom0stat);

xenstore-srv/src/xenstore_srv.c

@@ -2121,8 +2121,7 @@ int xs_init_root(void)
 
 	sys_dlist_init(&root_xenstore.child_list);
 	sys_dnode_init(&root_xenstore.node);
-	set_perms_by_array(&root_xenstore, &permissions, 1);
 
-	return 0;
+	return set_perms_by_array(&root_xenstore, &permissions, 1);
 }