This is a bit nasty: the machine is storing a string and later
resolving it.  We probably want to remove the memdev property
and instead make this a memory-set command.  "-M memdev" can be
handled a legacy option that is special cased by
machine_set_property.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 softmmu/vl.c | 70 +++++++++++++++++++++++++++-------------------------
 1 file changed, 37 insertions(+), 33 deletions(-)

diff --git a/softmmu/vl.c b/softmmu/vl.c
index acf09b2040..891f959572 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -2846,6 +2846,42 @@ static bool have_custom_ram_size(void)
     return !!qemu_opt_get_size(opts, "size", 0);
 }
 
+static void qemu_resolve_machine_memdev(void)
+{
+    if (current_machine->ram_memdev_id) {
+        Object *backend;
+        ram_addr_t backend_size;
+
+        backend = object_resolve_path_type(current_machine->ram_memdev_id,
+                                           TYPE_MEMORY_BACKEND, NULL);
+        if (!backend) {
+            error_report("Memory backend '%s' not found",
+                         current_machine->ram_memdev_id);
+            exit(EXIT_FAILURE);
+        }
+        backend_size = object_property_get_uint(backend, "size",  &error_abort);
+        if (have_custom_ram_size() && backend_size != ram_size) {
+                error_report("Size specified by -m option must match size of "
+                             "explicitly specified 'memory-backend' property");
+                exit(EXIT_FAILURE);
+        }
+        if (mem_path) {
+            error_report("'-mem-path' can't be used together with"
+                         "'-machine memory-backend'");
+            exit(EXIT_FAILURE);
+        }
+        ram_size = backend_size;
+    }
+
+    if (!xen_enabled()) {
+        /* On 32-bit hosts, QEMU is limited by virtual address space */
+        if (ram_size > (2047 << 20) && HOST_LONG_BITS == 32) {
+            error_report("at most 2047 MB RAM can be simulated");
+            exit(1);
+        }
+    }
+}
+
 static void set_memory_options(MachineClass *mc)
 {
     uint64_t sz;
@@ -4474,39 +4510,7 @@ void qemu_init(int argc, char **argv, char **envp)
         current_machine->cpu_type = parse_cpu_option(cpu_option);
     }
 
-    if (current_machine->ram_memdev_id) {
-        Object *backend;
-        ram_addr_t backend_size;
-
-        backend = object_resolve_path_type(current_machine->ram_memdev_id,
-                                           TYPE_MEMORY_BACKEND, NULL);
-        if (!backend) {
-            error_report("Memory backend '%s' not found",
-                         current_machine->ram_memdev_id);
-            exit(EXIT_FAILURE);
-        }
-        backend_size = object_property_get_uint(backend, "size",  &error_abort);
-        if (have_custom_ram_size() && backend_size != ram_size) {
-                error_report("Size specified by -m option must match size of "
-                             "explicitly specified 'memory-backend' property");
-                exit(EXIT_FAILURE);
-        }
-        if (mem_path) {
-            error_report("'-mem-path' can't be used together with"
-                         "'-machine memory-backend'");
-            exit(EXIT_FAILURE);
-        }
-        ram_size = backend_size;
-    }
-
-    if (!xen_enabled()) {
-        /* On 32-bit hosts, QEMU is limited by virtual address space */
-        if (ram_size > (2047 << 20) && HOST_LONG_BITS == 32) {
-            error_report("at most 2047 MB RAM can be simulated");
-            exit(1);
-        }
-    }
-
+    qemu_resolve_machine_memdev();
     parse_numa_opts(current_machine);
 
     /* do monitor/qmp handling at preconfig state if requested */
-- 
2.26.2