[PATCH] hw/ipmi: Allow multiple BMC instances

[Corey Minyard <corey@minyard.net>]

Allow a system to have multiple BMC connections to the same BMC and
multiple different BMCs.  This can happen on real systems, and is
useful for testing the IPMI driver on Linux.

Signed-off-by: Corey Minyard <corey@minyard.net>
---
I'm working on a fairly extensive test suite for IPMI, the Linux
driver and qemu, and this is necessary for some driver tests.

 hw/ipmi/ipmi.c            | 1 +
 hw/ipmi/ipmi_bmc_extern.c | 5 +++--
 hw/ipmi/ipmi_bmc_sim.c    | 2 +-
 include/hw/ipmi/ipmi.h    | 1 +
 qemu-options.hx           | 9 ++++++++-
 5 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/hw/ipmi/ipmi.c b/hw/ipmi/ipmi.c
index fdeaa5269f..ffd972f78b 100644
--- a/hw/ipmi/ipmi.c
+++ b/hw/ipmi/ipmi.c
@@ -110,6 +110,7 @@ void ipmi_bmc_find_and_link(Object *obj, Object **bmc)
 
 static const Property ipmi_bmc_properties[] = {
     DEFINE_PROP_UINT8("slave_addr",  IPMIBmc, slave_addr, 0x20),
+    DEFINE_PROP_UINT8("instance",    IPMIBmc, instance, 0),
 };
 
 static void bmc_class_init(ObjectClass *oc, void *data)
diff --git a/hw/ipmi/ipmi_bmc_extern.c b/hw/ipmi/ipmi_bmc_extern.c
index d015500254..11c28d03ab 100644
--- a/hw/ipmi/ipmi_bmc_extern.c
+++ b/hw/ipmi/ipmi_bmc_extern.c
@@ -488,7 +488,8 @@ static const VMStateDescription vmstate_ipmi_bmc_extern = {
 
 static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
 {
-    IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(dev);
+    IPMIBmc *b = IPMI_BMC(dev);
+    IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(b);
 
     if (!qemu_chr_fe_backend_connected(&ibe->chr)) {
         error_setg(errp, "IPMI external bmc requires chardev attribute");
@@ -498,7 +499,7 @@ static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
     qemu_chr_fe_set_handlers(&ibe->chr, can_receive, receive,
                              chr_event, NULL, ibe, NULL, true);
 
-    vmstate_register(NULL, 0, &vmstate_ipmi_bmc_extern, ibe);
+    vmstate_register(NULL, b->instance, &vmstate_ipmi_bmc_extern, ibe);
 }
 
 static void ipmi_bmc_extern_init(Object *obj)
diff --git a/hw/ipmi/ipmi_bmc_sim.c b/hw/ipmi/ipmi_bmc_sim.c
index 6157ac7120..c1b39dbdc5 100644
--- a/hw/ipmi/ipmi_bmc_sim.c
+++ b/hw/ipmi/ipmi_bmc_sim.c
@@ -2188,7 +2188,7 @@ static void ipmi_sim_realize(DeviceState *dev, Error **errp)
 
     ibs->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ipmi_timeout, ibs);
 
-    vmstate_register(NULL, 0, &vmstate_ipmi_sim, ibs);
+    vmstate_register(NULL, b->instance, &vmstate_ipmi_sim, ibs);
 }
 
 static const Property ipmi_sim_properties[] = {
diff --git a/include/hw/ipmi/ipmi.h b/include/hw/ipmi/ipmi.h
index 77a7213ed9..4436d70842 100644
--- a/include/hw/ipmi/ipmi.h
+++ b/include/hw/ipmi/ipmi.h
@@ -183,6 +183,7 @@ struct IPMIBmc {
     DeviceState parent;
 
     uint8_t slave_addr;
+    uint8_t instance;
 
     IPMIInterface *intf;
 };
diff --git a/qemu-options.hx b/qemu-options.hx
index dc694a99a3..186433ac13 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1120,6 +1120,10 @@ SRST
     ``slave_addr=val``
         Define slave address to use for the BMC. The default is 0x20.
 
+    ``instance=val``
+        For more than one BMC on the same system, each instance needs
+	a unique number.  The default is 0.
+
     ``sdrfile=file``
         file containing raw Sensor Data Records (SDR) data. The default
         is none.
@@ -1137,7 +1141,7 @@ SRST
         is set, get "Get GUID" command to the BMC will return it.
         Otherwise "Get GUID" will return an error.
 
-``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]``
+``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val][,instance=id]``
     Add a connection to an external IPMI BMC simulator. Instead of
     locally emulating the BMC like the above item, instead connect to an
     external entity that provides the IPMI services.
@@ -1151,6 +1155,9 @@ SRST
     simulator running on a secure port on localhost, so neither the
     simulator nor QEMU is exposed to any outside network.
 
+    You can have more than one external BMC connection with this, but
+    you must set a unique instance for each BMC.
+
     See the "lanserv/README.vm" file in the OpenIPMI library for more
     details on the external interface.
 
-- 
2.43.0