Generalize -machine command line option

-machine somehow suggests that it selects the machine, but it doesn't.
Fix that before this command is set in stone.

Actually, -machine should supersede -M and allow to introduce arbitrary
per-machine options to the command line. That will change the internal
realization again, but we will be able to keep the user interface
stable.

Tested-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

qemu-config.c

@@ -464,9 +464,14 @@ QemuOptsList qemu_option_rom_opts = {
 
 static QemuOptsList qemu_machine_opts = {
     .name = "machine",
+    .implied_opt_name = "type",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_machine_opts.head),
     .desc = {
         {
+            .name = "type",
+            .type = QEMU_OPT_STRING,
+            .help = "emulated machine"
+        }, {
             .name = "accel",
             .type = QEMU_OPT_STRING,
             .help = "accelerator list",

qemu-options.hx

@@ -2075,13 +2075,23 @@ if KVM support is enabled when compiling.
 ETEXI
 
 DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
-    "-machine accel=accel1[:accel2]    use an accelerator (kvm,xen,tcg), default is tcg\n", QEMU_ARCH_ALL)
+    "-machine [type=]name[,prop[=value][,...]]\n"
+    "                selects emulated machine (-machine ? for list)\n"
+    "                property accel=accel1[:accel2[:...]] selects accelerator\n"
+    "                supported accelerators are kvm, xen, tcg (default: tcg)\n",
+    QEMU_ARCH_ALL)
 STEXI
-@item -machine accel=@var{accels}
+@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
 @findex -machine
-This is use to enable an accelerator, in kvm,xen,tcg.
+Select the emulated machine by @var{name}. Use @code{-machine ?} to list
-By default, it use only tcg. If there a more than one accelerator
+available machines. Supported machine properties are:
-specified, the next one is used if the first don't work.
+@table @option
+@item accel=@var{accels1}[:@var{accels2}[:...]]
+This is used to enable an accelerator. Depending on the target architecture,
+kvm, xen, or tcg can be available. By default, tcg is used. If there is more
+than one accelerator specified, the next one is used if the previous one fails
+to initialize.
+@end table
 ETEXI
 
 DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,

vl.c

@@ -1899,6 +1899,27 @@ static int debugcon_parse(const char *devname)
     return 0;
 }
 
+static QEMUMachine *machine_parse(const char *name)
+{
+    QEMUMachine *m, *machine = NULL;
+
+    if (name) {
+        machine = find_machine(name);
+    }
+    if (machine) {
+        return machine;
+    }
+    printf("Supported machines are:\n");
+    for (m = first_machine; m != NULL; m = m->next) {
+        if (m->alias) {
+            printf("%-10s %s (alias of %s)\n", m->alias, m->desc, m->name);
+        }
+        printf("%-10s %s%s\n", m->name, m->desc,
+               m->is_default ? " (default)" : "");
+    }
+    exit(!name || *name != '?');
+}
+
 static int tcg_init(void)
 {
     return 0;
@@ -2155,20 +2176,7 @@ int main(int argc, char **argv, char **envp)
             }
             switch(popt->index) {
             case QEMU_OPTION_M:
-                machine = find_machine(optarg);
+                machine = machine_parse(optarg);
-                if (!machine) {
-                    QEMUMachine *m;
-                    printf("Supported machines are:\n");
-                    for(m = first_machine; m != NULL; m = m->next) {
-                        if (m->alias)
-                            printf("%-10s %s (alias of %s)\n",
-                                   m->alias, m->desc, m->name);
-                        printf("%-10s %s%s\n",
-                               m->name, m->desc,
-                               m->is_default ? " (default)" : "");
-                    }
-                    exit(*optarg != '?');
-                }
                 break;
             case QEMU_OPTION_cpu:
                 /* hw initialization will check this */
@@ -2698,11 +2706,12 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_machine:
                 olist = qemu_find_opts("machine");
                 qemu_opts_reset(olist);
-                opts = qemu_opts_parse(olist, optarg, 0);
+                opts = qemu_opts_parse(olist, optarg, 1);
                 if (!opts) {
                     fprintf(stderr, "parse error: %s\n", optarg);
                     exit(1);
                 }
+                machine = machine_parse(qemu_opt_get(opts, "type"));
                 break;
             case QEMU_OPTION_usb:
                 usb_enabled = 1;
@@ -2976,8 +2985,8 @@ int main(int argc, char **argv, char **envp)
             p = qemu_opt_get(QTAILQ_FIRST(&list->head), "accel");
         }
         if (p == NULL) {
-            opts = qemu_opts_parse(qemu_find_opts("machine"),
+            qemu_opts_reset(list);
-                                   machine->default_machine_opts, 0);
+            opts = qemu_opts_parse(list, machine->default_machine_opts, 0);
             if (!opts) {
                 fprintf(stderr, "parse error for machine %s: %s\n",
                         machine->name, machine->default_machine_opts);