vl: fix [memory] section with -readconfig

The -M memory.* options do not have magic applied to them like the -m
option, namely no "M" (for mebibytes) is tacked at the end of a suffixless
value for "-M memory.size".

This magic is performed by parse_memory_options, and we have to do it for
both "-m" and the [memory] section of a config file.  Storing [memory]
sections directly to machine_opts_dict changed the meaning of

    [memory]
      size = "1024"

in a -readconfig file from 1024MiB to 8KiB (1024 Bytes rounded up to
8KiB silently).  To avoid this, the [memory] section has to be changed
back to QemuOpts (combining [memory] and "-m" will work fine thanks to
.merge_lists being true).

Change parse_memory_options() so that, similar to the older function
set_memory_options(), it operates after command line parsing is done;
and also call it where set_memory_options() used to be.

Note, the parsing code uses exit(1) instead of exit(EXIT_FAILURE) to
match neighboring code.

Reported-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Fixes: ce9d03fb3f ("machine: add mem compound property", 2022-05-12)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

softmmu/vl.c

@@ -1947,16 +1947,15 @@ static void qemu_resolve_machine_memdev(void)
     }
 }
 
-static void parse_memory_options(const char *arg)
+static void parse_memory_options(void)
 {
-    QemuOpts *opts;
+    QemuOpts *opts = qemu_find_opts_singleton("memory");
     QDict *dict, *prop;
     const char *mem_str;
+    Location loc;
 
-    opts = qemu_opts_parse_noisily(qemu_find_opts("memory"), arg, true);
+    loc_push_none(&loc);
-    if (!opts) {
+    qemu_opts_loc_restore(opts);
-        exit(EXIT_FAILURE);
-    }
 
     prop = qdict_new();
 
@@ -1987,6 +1986,7 @@ static void parse_memory_options(const char *arg)
     qdict_put(dict, "memory", prop);
     keyval_merge(machine_opts_dict, dict, &error_fatal);
     qobject_unref(dict);
+    loc_pop(&loc);
 }
 
 static void qemu_create_machine(QDict *qdict)
@@ -2053,8 +2053,7 @@ static bool is_qemuopts_group(const char *group)
     if (g_str_equal(group, "object") ||
         g_str_equal(group, "machine") ||
         g_str_equal(group, "smp-opts") ||
-        g_str_equal(group, "boot-opts") ||
+        g_str_equal(group, "boot-opts")) {
-        g_str_equal(group, "memory")) {
         return false;
     }
     return true;
@@ -2078,8 +2077,6 @@ static void qemu_record_config_group(const char *group, QDict *dict,
         machine_merge_property("smp", dict, &error_fatal);
     } else if (g_str_equal(group, "boot-opts")) {
         machine_merge_property("boot", dict, &error_fatal);
-    } else if (g_str_equal(group, "memory")) {
-        machine_merge_property("memory", dict, &error_fatal);
     } else {
         abort();
     }
@@ -2882,7 +2879,10 @@ void qemu_init(int argc, char **argv, char **envp)
                 exit(0);
                 break;
             case QEMU_OPTION_m:
-                parse_memory_options(optarg);
+                opts = qemu_opts_parse_noisily(qemu_find_opts("memory"), optarg, true);
+                if (opts == NULL) {
+                    exit(1);
+                }
                 break;
 #ifdef CONFIG_TPM
             case QEMU_OPTION_tpmdev:
@@ -3515,6 +3515,9 @@ void qemu_init(int argc, char **argv, char **envp)
 
     configure_rtc(qemu_find_opts_singleton("rtc"));
 
+    /* Transfer QemuOpts options into machine options */
+    parse_memory_options();
+
     qemu_create_machine(machine_opts_dict);
 
     suspend_mux_open();