hw/misc: Add an iBT device model

Implement an IPMI BT interface model using a chardev backend to
communicate with an external PowerNV machine. It uses the OpenIPMI
simulator protocol for virtual machines described in :

    https://github.com/cminyard/openipmi/blob/master/lanserv/README.vm

and implemented by the 'ipmi-bmc-extern' model on the host side.

To use, start the Aspeed BMC machine with :

    -chardev socket,id=ipmi0,host=localhost,port=9002,ipv4,server,nowait \
    -global driver=aspeed.ibt,property=chardev,value=ipmi0

and the PowerNV machine with :

    -chardev socket,id=ipmi0,host=localhost,port=9002,reconnect=10 \
    -device ipmi-bmc-extern,id=bmc0,chardev=ipmi0 \
    -device isa-ipmi-bt,bmc=bmc0,irq=10 -nodefaults

Cc: Hao Wu <wuhaotsh@google.com>
Cc: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20210407171637.777743-20-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/arm/aspeed_ast2600.c

@@ -217,6 +217,8 @@ static void aspeed_soc_ast2600_init(Object *obj)
 
     object_initialize_child(obj, "lpc", &s->lpc, TYPE_ASPEED_LPC);
 
+    object_initialize_child(obj, "ibt", &s->ibt, TYPE_ASPEED_IBT);
+
     snprintf(typename, sizeof(typename), "aspeed.hace-%s", socname);
     object_initialize_child(obj, "hace", &s->hace, typename);
 
@@ -510,6 +512,16 @@ static void aspeed_soc_ast2600_realize(DeviceState *dev, Error **errp)
                        qdev_get_gpio_in(DEVICE(&s->a7mpcore),
                                 sc->irqmap[ASPEED_DEV_KCS] + aspeed_lpc_kcs_4));
 
+    /* iBT */
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->ibt), errp)) {
+        return;
+    }
+    memory_region_add_subregion(&s->lpc.iomem,
+                   sc->memmap[ASPEED_DEV_IBT] - sc->memmap[ASPEED_DEV_LPC],
+                   &s->ibt.iomem);
+    sysbus_connect_irq(SYS_BUS_DEVICE(&s->ibt), 0,
+                       aspeed_soc_get_irq(s, ASPEED_DEV_IBT));
+
     /* HACE */
     object_property_set_link(OBJECT(&s->hace), "dram", OBJECT(s->dram_mr),
                              &error_abort);

hw/arm/aspeed_soc.c

@@ -217,6 +217,8 @@ static void aspeed_soc_init(Object *obj)
 
     object_initialize_child(obj, "lpc", &s->lpc, TYPE_ASPEED_LPC);
 
+    object_initialize_child(obj, "ibt", &s->ibt, TYPE_ASPEED_IBT);
+
     snprintf(typename, sizeof(typename), "aspeed.hace-%s", socname);
     object_initialize_child(obj, "hace", &s->hace, typename);
 
@@ -439,6 +441,16 @@ static void aspeed_soc_realize(DeviceState *dev, Error **errp)
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->lpc), 1 + aspeed_lpc_kcs_4,
                        qdev_get_gpio_in(DEVICE(&s->lpc), aspeed_lpc_kcs_4));
 
+    /* iBT */
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->ibt), errp)) {
+        return;
+    }
+    memory_region_add_subregion(&s->lpc.iomem,
+                   sc->memmap[ASPEED_DEV_IBT] - sc->memmap[ASPEED_DEV_LPC],
+                   &s->ibt.iomem);
+    sysbus_connect_irq(SYS_BUS_DEVICE(&s->lpc), 1 + aspeed_lpc_ibt,
+                       qdev_get_gpio_in(DEVICE(&s->lpc), aspeed_lpc_ibt));
+
     /* HACE */
     object_property_set_link(OBJECT(&s->hace), "dram", OBJECT(s->dram_mr),
                              &error_abort);