QemuOpts: Convert qemu_opts_set() to Error, fix its use

Return the Error object instead of reporting it with
qerror_report_err().

Change callers that assume the function can't fail to pass
&error_abort, so that should the assumption ever break, it'll break
noisily.

Turns out all callers outside its unit test assume that.  We could
drop the Error ** argument, but that would make the interface less
regular, so don't.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

include/qemu/option.h

@@ -110,8 +110,8 @@ QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,
                            int fail_if_exists, Error **errp);
 void qemu_opts_reset(QemuOptsList *list);
 void qemu_opts_loc_restore(QemuOpts *opts);
-int qemu_opts_set(QemuOptsList *list, const char *id,
-                  const char *name, const char *value);
+void qemu_opts_set(QemuOptsList *list, const char *id,
+                   const char *name, const char *value, Error **errp);
 const char *qemu_opts_id(QemuOpts *opts);
 void qemu_opts_set_id(QemuOpts *opts, char *id);
 void qemu_opts_del(QemuOpts *opts);

net/net.c

@@ -1296,9 +1296,9 @@ int net_init_clients(void)
 
     if (default_net) {
         /* if no clients, we use a default config */
-        qemu_opts_set(net, NULL, "type", "nic");
+        qemu_opts_set(net, NULL, "type", "nic", &error_abort);
 #ifdef CONFIG_SLIRP
-        qemu_opts_set(net, NULL, "type", "user");
+        qemu_opts_set(net, NULL, "type", "user", &error_abort);
 #endif
     }
 

tests/test-qemu-opts.c

@@ -388,9 +388,9 @@ static void test_qemu_opts_reset(void)
 
 static void test_qemu_opts_set(void)
 {
+    Error *err = NULL;
     QemuOptsList *list;
     QemuOpts *opts;
-    int ret;
     const char *opt;
 
     list = qemu_find_opts("opts_list_01");
@@ -403,8 +403,8 @@ static void test_qemu_opts_set(void)
     g_assert(opts == NULL);
 
     /* implicitly create opts and set str3 value */
-    ret = qemu_opts_set(list, NULL, "str3", "value");
-    g_assert(ret == 0);
+    qemu_opts_set(list, NULL, "str3", "value", &err);
+    g_assert(!err);
     g_assert(!QTAILQ_EMPTY(&list->head));
 
     /* get the just created opts */

util/qemu-option.c

@@ -690,19 +690,18 @@ void qemu_opts_loc_restore(QemuOpts *opts)
     loc_restore(&opts->loc);
 }
 
-int qemu_opts_set(QemuOptsList *list, const char *id,
-                  const char *name, const char *value)
+void qemu_opts_set(QemuOptsList *list, const char *id,
+                   const char *name, const char *value, Error **errp)
 {
     QemuOpts *opts;
     Error *local_err = NULL;
 
     opts = qemu_opts_create(list, id, 1, &local_err);
     if (local_err) {
-        qerror_report_err(local_err);
-        error_free(local_err);
-        return -1;
+        error_propagate(errp, local_err);
+        return;
     }
-    return qemu_opt_set(opts, name, value);
+    qemu_opt_set_err(opts, name, value, errp);
 }
 
 const char *qemu_opts_id(QemuOpts *opts)

vl.c

@@ -3023,16 +3023,20 @@ int main(int argc, char **argv, char **envp)
                 }
                 break;
             case QEMU_OPTION_kernel:
-                qemu_opts_set(qemu_find_opts("machine"), 0, "kernel", optarg);
+                qemu_opts_set(qemu_find_opts("machine"), 0, "kernel", optarg,
+                              &error_abort);
                 break;
             case QEMU_OPTION_initrd:
-                qemu_opts_set(qemu_find_opts("machine"), 0, "initrd", optarg);
+                qemu_opts_set(qemu_find_opts("machine"), 0, "initrd", optarg,
+                              &error_abort);
                 break;
             case QEMU_OPTION_append:
-                qemu_opts_set(qemu_find_opts("machine"), 0, "append", optarg);
+                qemu_opts_set(qemu_find_opts("machine"), 0, "append", optarg,
+                              &error_abort);
                 break;
             case QEMU_OPTION_dtb:
-                qemu_opts_set(qemu_find_opts("machine"), 0, "dtb", optarg);
+                qemu_opts_set(qemu_find_opts("machine"), 0, "dtb", optarg,
+                              &error_abort);
                 break;
             case QEMU_OPTION_cdrom:
                 drive_add(IF_DEFAULT, 2, optarg, CDROM_OPTS);
@@ -3136,7 +3140,8 @@ int main(int argc, char **argv, char **envp)
                 }
                 break;
             case QEMU_OPTION_bios:
-                qemu_opts_set(qemu_find_opts("machine"), 0, "firmware", optarg);
+                qemu_opts_set(qemu_find_opts("machine"), 0, "firmware", optarg,
+                              &error_abort);
                 break;
             case QEMU_OPTION_singlestep:
                 singlestep = 1;