pvpanic: pass configurable ioport to seabios

This lets seabios patch the corresponding SSDT entry.

Also add fw_cfg object to /machine/fw_cfg so we can reference
it elsewhere.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 60c65d95fe2b23b12bea67099126566010a11a1a.1366945969.git.hutao@cn.fujitsu.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/misc/pvpanic.c b/hw/misc/pvpanic.c
index 01cfe0b..a80fae5 100644
--- a/hw/misc/pvpanic.c
+++ b/hw/misc/pvpanic.c
@@ -18,6 +18,8 @@
 #include "sysemu/sysemu.h"
 #include "qemu/log.h"
 
+#include "hw/nvram/fw_cfg.h"
+
 /* The bit of supported pv event */
 #define PVPANIC_F_PANICKED      0
 
@@ -86,10 +88,22 @@
 static int pvpanic_isa_initfn(ISADevice *dev)
 {
     PVPanicState *s = ISA_PVPANIC_DEVICE(dev);
+    static bool port_configured;
+    void *fw_cfg;
 
     memory_region_init_io(&s->io, &pvpanic_ops, s, "pvpanic", 1);
     isa_register_ioport(dev, &s->io, s->ioport);
 
+    if (!port_configured) {
+        fw_cfg = object_resolve_path("/machine/fw_cfg", NULL);
+        if (fw_cfg) {
+            fw_cfg_add_file(fw_cfg, "etc/pvpanic-port",
+                            g_memdup(&s->ioport, sizeof(s->ioport)),
+                            sizeof(s->ioport));
+            port_configured = true;
+        }
+    }
+
     return 0;
 }
 
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 97bba87..1a7e49c 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -489,11 +489,17 @@
     dev = qdev_create(NULL, "fw_cfg");
     qdev_prop_set_uint32(dev, "ctl_iobase", ctl_port);
     qdev_prop_set_uint32(dev, "data_iobase", data_port);
-    qdev_init_nofail(dev);
     d = SYS_BUS_DEVICE(dev);
 
     s = DO_UPCAST(FWCfgState, busdev.qdev, dev);
 
+    if (!object_resolve_path("/machine/fw_cfg", NULL)) {
+        object_property_add_child(qdev_get_machine(), "fw_cfg", OBJECT(s),
+                                  NULL);
+    }
+
+    qdev_init_nofail(dev);
+
     if (ctl_addr) {
         sysbus_mmio_map(d, 0, ctl_addr);
     }