ipmi: Add a UUID device property

Using the UUID that qemu generates probably isn't the best thing
to do, allow it to be passed in via properties, and use QemuUUID
for the type.

If the UUID is not set, return an unsupported command error.  This
way we are not providing an all-zero (or randomly generated) GUID
to the IPMI user.  This lets the host fall back to the other
method of using the get device id command to determind the BMC
being accessed.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Cédric Le Goater <clg@kaod.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/hw/ipmi/ipmi_bmc_sim.c b/hw/ipmi/ipmi_bmc_sim.c
index 6e6cd1b..71e56f3 100644
--- a/hw/ipmi/ipmi_bmc_sim.c
+++ b/hw/ipmi/ipmi_bmc_sim.c
@@ -223,7 +223,7 @@
     uint8_t restart_cause;
 
     uint8_t acpi_power_state[2];
-    uint8_t uuid[16];
+    QemuUUID uuid;
 
     IPMISel sel;
     IPMISdr sdr;
@@ -941,8 +941,19 @@
 {
     unsigned int i;
 
+    /* An uninitialized uuid is all zeros, use that to know if it is set. */
     for (i = 0; i < 16; i++) {
-        rsp_buffer_push(rsp, ibs->uuid[i]);
+        if (ibs->uuid.data[i]) {
+            goto uuid_set;
+        }
+    }
+    /* No uuid is set, return an error. */
+    rsp_buffer_set_error(rsp, IPMI_CC_INVALID_CMD);
+    return;
+
+ uuid_set:
+    for (i = 0; i < 16; i++) {
+        rsp_buffer_push(rsp, ibs->uuid.data[i]);
     }
 }
 
@@ -1986,12 +1997,6 @@
     ibs->acpi_power_state[0] = 0;
     ibs->acpi_power_state[1] = 0;
 
-    if (qemu_uuid_set) {
-        memcpy(&ibs->uuid, &qemu_uuid, 16);
-    } else {
-        memset(&ibs->uuid, 0, 16);
-    }
-
     ipmi_init_sensors_from_sdrs(ibs);
     register_cmds(ibs);
 
@@ -2011,6 +2016,7 @@
     DEFINE_PROP_UINT8("fwrev2", IPMIBmcSim, fwrev2, 0),
     DEFINE_PROP_UINT32("mfg_id", IPMIBmcSim, mfg_id, 0),
     DEFINE_PROP_UINT16("product_id", IPMIBmcSim, product_id, 0),
+    DEFINE_PROP_UUID_NODEFAULT("guid", IPMIBmcSim, uuid),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/qemu-options.hx b/qemu-options.hx
index bbfd936..ed9292f 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -701,7 +701,7 @@
 @code{-device @var{driver},help}.
 
 Some drivers are:
-@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}]
+@item -device ipmi-bmc-sim,id=@var{id}[,slave_addr=@var{val}][,sdrfile=@var{file}][,furareasize=@var{val}][,furdatafile=@var{file}][,guid=@var{uuid}]
 
 Add an IPMI BMC.  This is a simulation of a hardware management
 interface processor that normally sits on a system.  It provides
@@ -714,8 +714,8 @@
 it.
 
 @table @option
-@item bmc=@var{id}
-The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
+@item id=@var{id}
+The BMC id for interfaces to use this device.
 @item slave_addr=@var{val}
 Define slave address to use for the BMC.  The default is 0x20.
 @item sdrfile=@var{file}
@@ -724,6 +724,10 @@
 size of a Field Replaceable Unit (FRU) area.  The default is 1024.
 @item frudatafile=@var{file}
 file containing raw Field Replaceable Unit (FRU) inventory data. The default is none.
+@item guid=@var{uuid}
+value for the GUID for the BMC, in standard UUID format.  If this is set,
+get "Get GUID" command to the BMC will return it.  Otherwise "Get GUID"
+will return an error.
 @end table
 
 @item -device ipmi-bmc-extern,id=@var{id},chardev=@var{id}[,slave_addr=@var{val}]