[Qemu-devel] [FOR 0.12 PATCH v3 14/21] qdev: add command line option to set global defaults for properties.

[Gerd Hoffmann <kraxel@redhat.com>]

This patch adds infrastructure and command line option for setting
global defaults for device properties, i.e. you can for example use

  -global virtio-blk-pci.vectors=0

to turn off msi by default for all virtio block devices.  The config
file syntax is:

[global]
  driver = "virtio-blk-pci"
  property = "vectors"
  value = "0"

This can also be used to set properties for devices which are not
created via -device but implicitly via machine init, i.e.

  -global isa-fdc,driveA=<name>

This patch uses the mechanism which configures properties for the
compatibility machine types (pc-0.10 & friends).  The command line
takes precedence over the machine type values.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 qemu-config.c   |   56 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-config.h   |    2 +
 qemu-options.hx |    3 ++
 vl.c            |    6 +++++
 4 files changed, 67 insertions(+), 0 deletions(-)

diff --git a/qemu-config.c b/qemu-config.c
index 92b5363..a23b125 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -2,6 +2,7 @@
 #include "qemu-option.h"
 #include "qemu-config.h"
 #include "sysemu.h"
+#include "hw/qdev.h"
 
 QemuOptsList qemu_drive_opts = {
     .name = "drive",
@@ -205,6 +206,24 @@ QemuOptsList qemu_rtc_opts = {
     },
 };
 
+QemuOptsList qemu_global_opts = {
+    .name = "global",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_global_opts.head),
+    .desc = {
+        {
+            .name = "driver",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "property",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "value",
+            .type = QEMU_OPT_STRING,
+        },
+        { /* end if list */ }
+    },
+};
+
 static QemuOptsList *lists[] = {
     &qemu_drive_opts,
     &qemu_chardev_opts,
@@ -212,6 +231,7 @@ static QemuOptsList *lists[] = {
     &qemu_netdev_opts,
     &qemu_net_opts,
     &qemu_rtc_opts,
+    &qemu_global_opts,
     NULL,
 };
 
@@ -260,6 +280,42 @@ int qemu_set_option(const char *str)
     return 0;
 }
 
+int qemu_global_option(const char *str)
+{
+    char driver[64], property[64];
+    QemuOpts *opts;
+    int rc, offset;
+
+    rc = sscanf(str, "%63[^.].%63[^=]%n", driver, property, &offset);
+    if (rc < 2 || str[offset] != '=') {
+        qemu_error("can't parse: \"%s\"\n", str);
+        return -1;
+    }
+
+    opts = qemu_opts_create(&qemu_global_opts, NULL, 0);
+    qemu_opt_set(opts, "driver", driver);
+    qemu_opt_set(opts, "property", property);
+    qemu_opt_set(opts, "value", str+offset+1);
+    return 0;
+}
+
+static int qemu_add_one_global(QemuOpts *opts, void *opaque)
+{
+    GlobalProperty *g;
+
+    g = qemu_mallocz(sizeof(*g));
+    g->driver   = qemu_opt_get(opts, "driver");
+    g->property = qemu_opt_get(opts, "property");
+    g->value    = qemu_opt_get(opts, "value");
+    qdev_prop_register_global(g);
+    return 0;
+}
+
+void qemu_add_globals(void)
+{
+    qemu_opts_foreach(&qemu_global_opts, qemu_add_one_global, NULL, 0);
+}
+
 struct ConfigWriteData {
     QemuOptsList *list;
     FILE *fp;
diff --git a/qemu-config.h b/qemu-config.h
index b564851..6246e76 100644
--- a/qemu-config.h
+++ b/qemu-config.h
@@ -9,6 +9,8 @@ extern QemuOptsList qemu_net_opts;
 extern QemuOptsList qemu_rtc_opts;
 
 int qemu_set_option(const char *str);
+int qemu_global_option(const char *str);
+void qemu_add_globals(void);
 
 void qemu_config_write(FILE *fp);
 int qemu_config_parse(FILE *fp);
diff --git a/qemu-options.hx b/qemu-options.hx
index 70929fa..e05b2a0 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -109,6 +109,9 @@ DEF("set", HAS_ARG, QEMU_OPTION_set,
     "-set group.id.arg=value\n"
     "                set <arg> parameter for item <id> of type <group>\n"
     "                i.e. -set drive.$id.file=/path/to/image\n")
+DEF("global", HAS_ARG, QEMU_OPTION_global,
+    "-global driver.property=value\n"
+    "                set a global default for a driver property\n")
 STEXI
 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
 
diff --git a/vl.c b/vl.c
index aba4f62..4551ee8 100644
--- a/vl.c
+++ b/vl.c
@@ -4917,6 +4917,10 @@ int main(int argc, char **argv, char **envp)
                 if (qemu_set_option(optarg) != 0)
                     exit(1);
 	        break;
+            case QEMU_OPTION_global:
+                if (qemu_global_option(optarg) != 0)
+                    exit(1);
+	        break;
             case QEMU_OPTION_mtdblock:
                 drive_add(optarg, MTD_ALIAS);
                 break;
@@ -5792,6 +5796,8 @@ int main(int argc, char **argv, char **envp)
     if (machine->compat_props) {
         qdev_prop_register_global_list(machine->compat_props);
     }
+    qemu_add_globals();
+
     machine->init(ram_size, boot_devices,
                   kernel_filename, kernel_cmdline, initrd_filename, cpu_model);
 
-- 
1.6.5.2