Patchwork [11/16] introduce ICC bus/device/bridge

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Submitter Igor Mammedov
Date April 15, 2013, 10:12 p.m.
Message ID <1366063976-4909-12-git-send-email-imammedo@redhat.com>
Download mbox | patch
Permalink /patch/236742/
State New
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Comments

Igor Mammedov - April 15, 2013, 10:12 p.m.
... to provide hotplug-able bus.

* icc-bridge will serve as a parent for icc-bus and provide
  mmio mapping services to child icc-devices.
* icc-device will replace SysBusDevice as a parent of APIC
  and IOAPIC devices.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
v2:
  * Rebase on top the last HW reorganization series.
  * Move hw/icc_bus.c into hw/cpu/ and hw/icc_bus.h include/hw/i386/
---
 default-configs/i386-softmmu.mak   |  1 +
 default-configs/x86_64-softmmu.mak |  1 +
 hw/cpu/Makefile.objs               |  1 +
 hw/cpu/icc_bus.c                   | 88 ++++++++++++++++++++++++++++++++++++++
 hw/i386/pc_piix.c                  |  7 +++
 hw/i386/pc_q35.c                   |  7 +++
 include/hw/i386/icc_bus.h          | 53 +++++++++++++++++++++++
 7 files changed, 158 insertions(+)
 create mode 100644 hw/cpu/icc_bus.c
 create mode 100644 include/hw/i386/icc_bus.h
Peter Maydell - April 22, 2013, 11:39 a.m.
On 15 April 2013 23:12, Igor Mammedov <imammedo@redhat.com> wrote:
> ... to provide hotplug-able bus.
>
> * icc-bridge will serve as a parent for icc-bus and provide
>   mmio mapping services to child icc-devices.
> * icc-device will replace SysBusDevice as a parent of APIC
>   and IOAPIC devices.
>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> v2:
>   * Rebase on top the last HW reorganization series.
>   * Move hw/icc_bus.c into hw/cpu/ and hw/icc_bus.h include/hw/i386/

This seems inconsistent. I think the header should be in
include/hw/cpu/ to match the location of the .c file.

thanks
-- PMM
Paolo Bonzini - April 22, 2013, 12:27 p.m.
Il 22/04/2013 13:39, Peter Maydell ha scritto:
>> > ... to provide hotplug-able bus.
>> >
>> > * icc-bridge will serve as a parent for icc-bus and provide
>> >   mmio mapping services to child icc-devices.
>> > * icc-device will replace SysBusDevice as a parent of APIC
>> >   and IOAPIC devices.
>> >
>> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
>> > ---
>> > v2:
>> >   * Rebase on top the last HW reorganization series.
>> >   * Move hw/icc_bus.c into hw/cpu/ and hw/icc_bus.h include/hw/i386/
> This seems inconsistent. I think the header should be in
> include/hw/cpu/ to match the location of the .c file.

Agreed.

Paolo
Andreas Färber - April 22, 2013, 1:22 p.m.
Am 16.04.2013 00:12, schrieb Igor Mammedov:
> ... to provide hotplug-able bus.
> 
> * icc-bridge will serve as a parent for icc-bus and provide
>   mmio mapping services to child icc-devices.
> * icc-device will replace SysBusDevice as a parent of APIC
>   and IOAPIC devices.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> v2:
>   * Rebase on top the last HW reorganization series.
>   * Move hw/icc_bus.c into hw/cpu/ and hw/icc_bus.h include/hw/i386/

http://wiki.qemu.org/QOMConventions

Comments below...

> ---
>  default-configs/i386-softmmu.mak   |  1 +
>  default-configs/x86_64-softmmu.mak |  1 +
>  hw/cpu/Makefile.objs               |  1 +
>  hw/cpu/icc_bus.c                   | 88 ++++++++++++++++++++++++++++++++++++++
>  hw/i386/pc_piix.c                  |  7 +++
>  hw/i386/pc_q35.c                   |  7 +++
>  include/hw/i386/icc_bus.h          | 53 +++++++++++++++++++++++
>  7 files changed, 158 insertions(+)
>  create mode 100644 hw/cpu/icc_bus.c
>  create mode 100644 include/hw/i386/icc_bus.h
> 
> diff --git a/default-configs/i386-softmmu.mak b/default-configs/i386-softmmu.mak
> index 4ac0694..0789303 100644
> --- a/default-configs/i386-softmmu.mak
> +++ b/default-configs/i386-softmmu.mak
> @@ -45,3 +45,4 @@ CONFIG_LPC_ICH9=y
>  CONFIG_Q35=y
>  CONFIG_APIC=y
>  CONFIG_IOAPIC=y
> +CONFIG_ICC_BUS=y
> diff --git a/default-configs/x86_64-softmmu.mak b/default-configs/x86_64-softmmu.mak
> index bf4091c..8d03e9a 100644
> --- a/default-configs/x86_64-softmmu.mak
> +++ b/default-configs/x86_64-softmmu.mak
> @@ -45,3 +45,4 @@ CONFIG_LPC_ICH9=y
>  CONFIG_Q35=y
>  CONFIG_APIC=y
>  CONFIG_IOAPIC=y
> +CONFIG_ICC_BUS=y
> diff --git a/hw/cpu/Makefile.objs b/hw/cpu/Makefile.objs
> index a49ca04..4461ece 100644
> --- a/hw/cpu/Makefile.objs
> +++ b/hw/cpu/Makefile.objs
> @@ -1,4 +1,5 @@
>  obj-$(CONFIG_ARM11MPCORE) += arm11mpcore.o
>  obj-$(CONFIG_ARM9MPCORE) += a9mpcore.o
>  obj-$(CONFIG_ARM15MPCORE) += a15mpcore.o
> +obj-$(CONFIG_ICC_BUS) += icc_bus.o
>  
> diff --git a/hw/cpu/icc_bus.c b/hw/cpu/icc_bus.c
> new file mode 100644
> index 0000000..00b9be3
> --- /dev/null
> +++ b/hw/cpu/icc_bus.c
> @@ -0,0 +1,88 @@
> +/* icc_bus.c
> + * emulate x86 ICC(INTERRUPT CONTROLLER COMMUNICATIONS) bus

Does this need to be all-capitals? :)

> + *
> + * Copyright (c) 2013 Red Hat, Inc
> + *
> + * Authors:
> + *     Igor Mammedov <imammedo@redhat.com>
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>
> + */
> +#include "hw/i386/icc_bus.h"
> +#include "hw/sysbus.h"
> +
> +static void icc_bus_initfn(Object *obj)
> +{
> +    BusState *b = BUS(obj);

Whiteline as below?

> +    b->allow_hotplug = true;
> +}
> +
> +static const TypeInfo icc_bus_info = {
> +    .name = TYPE_ICC_BUS,
> +    .parent = TYPE_BUS,
> +    .instance_size = sizeof(ICCBus),
> +    .instance_init = icc_bus_initfn,
> +};
> +
> +static int icc_device_init(DeviceState *dev)
> +{
> +    ICCDevice *id = ICC_DEVICE(dev);
> +    ICCDeviceClass *k = ICC_DEVICE_GET_CLASS(id);
> +
> +    return k->init(id);
> +}
> +
> +static void icc_device_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *k = DEVICE_CLASS(klass);
> +
> +    k->init = icc_device_init;

Please use k->realize for any new base device type or type derived from
SysBusDevice.

If there's nothing to do at this level, you can just provide a dummy
realize function here to override Device's and override it (without
saving the parent's dummy function) in IOAPIC or wherever you need it.

> +    k->bus_type = TYPE_ICC_BUS;
> +}
> +
> +static const TypeInfo icc_device_info = {
> +    .name = TYPE_ICC_DEVICE,
> +    .parent = TYPE_DEVICE,
> +    .abstract = true,
> +    .instance_size = sizeof(ICCDevice),
> +    .class_size = sizeof(ICCDeviceClass),
> +    .class_init = icc_device_class_init,
> +};
> +
> +typedef struct ICCBridgeState {
> +    SysBusDevice busdev;

parent_obj please - makes it clear that it is a QOM struct and flags
accidental uses of obsolete SysBus macros.

> +} ICCBridgeState;
> +#define ICC_BRIGDE(obj) OBJECT_CHECK(ICCBridgeState, (obj), TYPE_ICC_BRIDGE)
> +
> +
> +static void icc_bridge_initfn(Object *obj)
> +{
> +    qbus_create(TYPE_ICC_BUS, DEVICE(obj), "icc-bus");

qbus_create_inplace()?

> +}
> +
> +static const TypeInfo icc_bridge_info = {
> +    .name  = "icc-bridge",

TYPE_ICC_BRIDGE?

> +    .parent = TYPE_SYS_BUS_DEVICE,
> +    .instance_init  = icc_bridge_initfn,
> +    .instance_size  = sizeof(ICCBridgeState),
> +};
> +
> +static void icc_bus_register_types(void)
> +{
> +    type_register_static(&icc_bus_info);
> +    type_register_static(&icc_device_info);
> +    type_register_static(&icc_bridge_info);
> +}
> +
> +type_init(icc_bus_register_types)

BTW Anthony recently suggested to drop the "fn" where there's no init
vs. initfn name conflicts; I don't mind either way.

> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index cff8013..d8c3e1a 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -37,6 +37,7 @@
>  #include "hw/kvm/clock.h"
>  #include "sysemu/sysemu.h"
>  #include "hw/sysbus.h"
> +#include "hw/i386/icc_bus.h"
>  #include "sysemu/arch_init.h"
>  #include "sysemu/blockdev.h"
>  #include "hw/i2c/smbus.h"
> @@ -84,8 +85,13 @@ static void pc_init1(MemoryRegion *system_memory,
>      MemoryRegion *ram_memory;
>      MemoryRegion *pci_memory;
>      MemoryRegion *rom_memory;
> +    DeviceState *icc_bridge;
>      void *fw_cfg = NULL;
>  
> +    icc_bridge = qdev_create(NULL, TYPE_ICC_BRIDGE);
> +    object_property_add_child(qdev_get_machine(), "icc-bridge",
> +                              OBJECT(icc_bridge), NULL);
> +
>      pc_cpus_init(cpu_model);
>      pc_acpi_init("acpi-dsdt.aml");
>  
> @@ -160,6 +166,7 @@ static void pc_init1(MemoryRegion *system_memory,
>      if (pci_enabled) {
>          ioapic_init_gsi(gsi_state, "i440fx");
>      }
> +    qdev_init_nofail(icc_bridge);
>  
>      pc_register_ferr_irq(gsi[13]);
>  
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 6ac1a89..9055145 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -41,6 +41,7 @@
>  #include "hw/ide/pci.h"
>  #include "hw/ide/ahci.h"
>  #include "hw/usb.h"
> +#include "hw/i386/icc_bus.h"
>  
>  /* ICH9 AHCI has 6 ports */
>  #define MAX_SATA_PORTS     6
> @@ -85,6 +86,11 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
>      ICH9LPCState *ich9_lpc;
>      PCIDevice *ahci;
>      qemu_irq *cmos_s3;
> +    DeviceState *icc_bridge;
> +
> +    icc_bridge = qdev_create(NULL, TYPE_ICC_BRIDGE);
> +    object_property_add_child(qdev_get_machine(), "icc-bridge",
> +                              OBJECT(icc_bridge), NULL);
>  
>      pc_cpus_init(cpu_model);
>      pc_acpi_init("q35-acpi-dsdt.aml");
> @@ -168,6 +174,7 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
>      if (pci_enabled) {
>          ioapic_init_gsi(gsi_state, NULL);
>      }
> +    qdev_init_nofail(icc_bridge);
>  
>      pc_register_ferr_irq(gsi[13]);
>  
> diff --git a/include/hw/i386/icc_bus.h b/include/hw/i386/icc_bus.h
> new file mode 100644
> index 0000000..aa30e0c
> --- /dev/null
> +++ b/include/hw/i386/icc_bus.h
> @@ -0,0 +1,53 @@
> +/* icc_bus.h
> + * emulate x86 ICC(INTERRUPT CONTROLLER COMMUNICATIONS) bus
> + *
> + * Copyright (c) 2013 Red Hat, Inc
> + *
> + * Authors:
> + *     Igor Mammedov <imammedo@redhat.com>
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>
> + */
> +#ifndef ICC_BUS_H
> +#define ICC_BUS_H
> +
> +#include "hw/qdev-core.h"
> +
> +#define TYPE_ICC_BUS "icc-bus"
> +
> +#ifndef CONFIG_USER_ONLY
> +typedef struct ICCBus {

/*< private >*/

> +    BusState qbus;

parent_obj

/*< public >*/

...since it is in a header.

> +} ICCBus;
> +#define ICC_BUS(obj) OBJECT_CHECK(ICCBus, (obj), TYPE_ICC_BUS)
> +
> +typedef struct ICCDevice {
> +    DeviceState qdev;

dito

> +} ICCDevice;
> +
> +typedef struct ICCDeviceClass {
> +    DeviceClass parent_class;
> +    int (*init)(ICCDevice *dev);

Please read the realize documentation in qdev-core.h - instead of having
the device provide a specialized init hook, it should override (and if
necessary, save) the parent's realize callback.

> +} ICCDeviceClass;
> +#define TYPE_ICC_DEVICE "icc-device"
> +#define ICC_DEVICE(obj) OBJECT_CHECK(ICCDevice, (obj), TYPE_ICC_DEVICE)
> +#define ICC_DEVICE_CLASS(klass) \
> +     OBJECT_CLASS_CHECK(ICCDeviceClass, (klass), TYPE_ICC_DEVICE)
> +#define ICC_DEVICE_GET_CLASS(obj) \
> +     OBJECT_GET_CLASS(ICCDeviceClass, (obj), TYPE_ICC_DEVICE)
> +
> +#define TYPE_ICC_BRIDGE "icc-bridge"
> +
> +#endif /* CONFIG_USER_ONLY */
> +#endif

General concept looks fine to me. Maybe add a bit more whiteline spacing
between struct and macros and between different QOM types in .c.

Who becomes the MAINTAINER of ICC?

Regards,
Andreas
Igor Mammedov - April 22, 2013, 3:08 p.m.
On Mon, 22 Apr 2013 15:22:30 +0200
Andreas Färber <afaerber@suse.de> wrote:

> Am 16.04.2013 00:12, schrieb Igor Mammedov:
> > ... to provide hotplug-able bus.
> > 
> > * icc-bridge will serve as a parent for icc-bus and provide
> >   mmio mapping services to child icc-devices.
> > * icc-device will replace SysBusDevice as a parent of APIC
> >   and IOAPIC devices.
> > 
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> > v2:
> >   * Rebase on top the last HW reorganization series.
> >   * Move hw/icc_bus.c into hw/cpu/ and hw/icc_bus.h include/hw/i386/
> 
> http://wiki.qemu.org/QOMConventions
> 
> Comments below...
> 
[...]
> > +
> > +static void icc_device_class_init(ObjectClass *klass, void *data)
> > +{
> > +    DeviceClass *k = DEVICE_CLASS(klass);
> > +
> > +    k->init = icc_device_init;
> 
> Please use k->realize for any new base device type or type derived from
> SysBusDevice.
> 
> If there's nothing to do at this level, you can just provide a dummy
> realize function here to override Device's and override it (without
> saving the parent's dummy function) in IOAPIC or wherever you need it.
>
I'll try it, and if changes isn't big, I'll merge into this patch.

> > +    k->bus_type = TYPE_ICC_BUS;
> > +}
> > +
> > +static const TypeInfo icc_device_info = {
> > +    .name = TYPE_ICC_DEVICE,
> > +    .parent = TYPE_DEVICE,
> > +    .abstract = true,
> > +    .instance_size = sizeof(ICCDevice),
> > +    .class_size = sizeof(ICCDeviceClass),
> > +    .class_init = icc_device_class_init,
> > +};
> > +
> > +typedef struct ICCBridgeState {
> > +    SysBusDevice busdev;
> 
> parent_obj please - makes it clear that it is a QOM struct and flags
> accidental uses of obsolete SysBus macros.
done

> 
> > +} ICCBridgeState;
> > +#define ICC_BRIGDE(obj) OBJECT_CHECK(ICCBridgeState, (obj),
> > TYPE_ICC_BRIDGE) +
> > +
> > +static void icc_bridge_initfn(Object *obj)
> > +{
> > +    qbus_create(TYPE_ICC_BUS, DEVICE(obj), "icc-bus");
> 
> qbus_create_inplace()?
done
 
[...]

> 
> BTW Anthony recently suggested to drop the "fn" where there's no init
> vs. initfn name conflicts; I don't mind either way.
changed to init
 
[...]
> 
> /*< private >*/
> 
> > +    BusState qbus;
> 
> parent_obj
done

> 
> /*< public >*/
> 
> ...since it is in a header.
> 
> > +} ICCBus;
> > +#define ICC_BUS(obj) OBJECT_CHECK(ICCBus, (obj), TYPE_ICC_BUS)
> > +
> > +typedef struct ICCDevice {
> > +    DeviceState qdev;
> 
> dito
s/qdev/parent_obj/ will affect APIC and IOAPIC patches make-ing them even
bigger and more difficult to review distracting from real changes.

it would be better to send follow-up patch, that does trivial QOM conversions
afterwards.

I'm not sure that making ICCDevice.qdev private would be good performance wise
since it would require using DEVICE() dynamic cast in apic_check_pic().

I'd like to keep this as is for now and put cleanup patch on TODO list for
1.6 to get rid of DO_UPCAST() macro in apic/ioapic files.

> 
> Who becomes the MAINTAINER of ICC?
Perhaps me??

> 
> Regards,
> Andreas
>

Patch

diff --git a/default-configs/i386-softmmu.mak b/default-configs/i386-softmmu.mak
index 4ac0694..0789303 100644
--- a/default-configs/i386-softmmu.mak
+++ b/default-configs/i386-softmmu.mak
@@ -45,3 +45,4 @@  CONFIG_LPC_ICH9=y
 CONFIG_Q35=y
 CONFIG_APIC=y
 CONFIG_IOAPIC=y
+CONFIG_ICC_BUS=y
diff --git a/default-configs/x86_64-softmmu.mak b/default-configs/x86_64-softmmu.mak
index bf4091c..8d03e9a 100644
--- a/default-configs/x86_64-softmmu.mak
+++ b/default-configs/x86_64-softmmu.mak
@@ -45,3 +45,4 @@  CONFIG_LPC_ICH9=y
 CONFIG_Q35=y
 CONFIG_APIC=y
 CONFIG_IOAPIC=y
+CONFIG_ICC_BUS=y
diff --git a/hw/cpu/Makefile.objs b/hw/cpu/Makefile.objs
index a49ca04..4461ece 100644
--- a/hw/cpu/Makefile.objs
+++ b/hw/cpu/Makefile.objs
@@ -1,4 +1,5 @@ 
 obj-$(CONFIG_ARM11MPCORE) += arm11mpcore.o
 obj-$(CONFIG_ARM9MPCORE) += a9mpcore.o
 obj-$(CONFIG_ARM15MPCORE) += a15mpcore.o
+obj-$(CONFIG_ICC_BUS) += icc_bus.o
 
diff --git a/hw/cpu/icc_bus.c b/hw/cpu/icc_bus.c
new file mode 100644
index 0000000..00b9be3
--- /dev/null
+++ b/hw/cpu/icc_bus.c
@@ -0,0 +1,88 @@ 
+/* icc_bus.c
+ * emulate x86 ICC(INTERRUPT CONTROLLER COMMUNICATIONS) bus
+ *
+ * Copyright (c) 2013 Red Hat, Inc
+ *
+ * Authors:
+ *     Igor Mammedov <imammedo@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ */
+#include "hw/i386/icc_bus.h"
+#include "hw/sysbus.h"
+
+static void icc_bus_initfn(Object *obj)
+{
+    BusState *b = BUS(obj);
+    b->allow_hotplug = true;
+}
+
+static const TypeInfo icc_bus_info = {
+    .name = TYPE_ICC_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(ICCBus),
+    .instance_init = icc_bus_initfn,
+};
+
+static int icc_device_init(DeviceState *dev)
+{
+    ICCDevice *id = ICC_DEVICE(dev);
+    ICCDeviceClass *k = ICC_DEVICE_GET_CLASS(id);
+
+    return k->init(id);
+}
+
+static void icc_device_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *k = DEVICE_CLASS(klass);
+
+    k->init = icc_device_init;
+    k->bus_type = TYPE_ICC_BUS;
+}
+
+static const TypeInfo icc_device_info = {
+    .name = TYPE_ICC_DEVICE,
+    .parent = TYPE_DEVICE,
+    .abstract = true,
+    .instance_size = sizeof(ICCDevice),
+    .class_size = sizeof(ICCDeviceClass),
+    .class_init = icc_device_class_init,
+};
+
+typedef struct ICCBridgeState {
+    SysBusDevice busdev;
+} ICCBridgeState;
+#define ICC_BRIGDE(obj) OBJECT_CHECK(ICCBridgeState, (obj), TYPE_ICC_BRIDGE)
+
+
+static void icc_bridge_initfn(Object *obj)
+{
+    qbus_create(TYPE_ICC_BUS, DEVICE(obj), "icc-bus");
+}
+
+static const TypeInfo icc_bridge_info = {
+    .name  = "icc-bridge",
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_init  = icc_bridge_initfn,
+    .instance_size  = sizeof(ICCBridgeState),
+};
+
+static void icc_bus_register_types(void)
+{
+    type_register_static(&icc_bus_info);
+    type_register_static(&icc_device_info);
+    type_register_static(&icc_bridge_info);
+}
+
+type_init(icc_bus_register_types)
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index cff8013..d8c3e1a 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -37,6 +37,7 @@ 
 #include "hw/kvm/clock.h"
 #include "sysemu/sysemu.h"
 #include "hw/sysbus.h"
+#include "hw/i386/icc_bus.h"
 #include "sysemu/arch_init.h"
 #include "sysemu/blockdev.h"
 #include "hw/i2c/smbus.h"
@@ -84,8 +85,13 @@  static void pc_init1(MemoryRegion *system_memory,
     MemoryRegion *ram_memory;
     MemoryRegion *pci_memory;
     MemoryRegion *rom_memory;
+    DeviceState *icc_bridge;
     void *fw_cfg = NULL;
 
+    icc_bridge = qdev_create(NULL, TYPE_ICC_BRIDGE);
+    object_property_add_child(qdev_get_machine(), "icc-bridge",
+                              OBJECT(icc_bridge), NULL);
+
     pc_cpus_init(cpu_model);
     pc_acpi_init("acpi-dsdt.aml");
 
@@ -160,6 +166,7 @@  static void pc_init1(MemoryRegion *system_memory,
     if (pci_enabled) {
         ioapic_init_gsi(gsi_state, "i440fx");
     }
+    qdev_init_nofail(icc_bridge);
 
     pc_register_ferr_irq(gsi[13]);
 
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 6ac1a89..9055145 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -41,6 +41,7 @@ 
 #include "hw/ide/pci.h"
 #include "hw/ide/ahci.h"
 #include "hw/usb.h"
+#include "hw/i386/icc_bus.h"
 
 /* ICH9 AHCI has 6 ports */
 #define MAX_SATA_PORTS     6
@@ -85,6 +86,11 @@  static void pc_q35_init(QEMUMachineInitArgs *args)
     ICH9LPCState *ich9_lpc;
     PCIDevice *ahci;
     qemu_irq *cmos_s3;
+    DeviceState *icc_bridge;
+
+    icc_bridge = qdev_create(NULL, TYPE_ICC_BRIDGE);
+    object_property_add_child(qdev_get_machine(), "icc-bridge",
+                              OBJECT(icc_bridge), NULL);
 
     pc_cpus_init(cpu_model);
     pc_acpi_init("q35-acpi-dsdt.aml");
@@ -168,6 +174,7 @@  static void pc_q35_init(QEMUMachineInitArgs *args)
     if (pci_enabled) {
         ioapic_init_gsi(gsi_state, NULL);
     }
+    qdev_init_nofail(icc_bridge);
 
     pc_register_ferr_irq(gsi[13]);
 
diff --git a/include/hw/i386/icc_bus.h b/include/hw/i386/icc_bus.h
new file mode 100644
index 0000000..aa30e0c
--- /dev/null
+++ b/include/hw/i386/icc_bus.h
@@ -0,0 +1,53 @@ 
+/* icc_bus.h
+ * emulate x86 ICC(INTERRUPT CONTROLLER COMMUNICATIONS) bus
+ *
+ * Copyright (c) 2013 Red Hat, Inc
+ *
+ * Authors:
+ *     Igor Mammedov <imammedo@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ */
+#ifndef ICC_BUS_H
+#define ICC_BUS_H
+
+#include "hw/qdev-core.h"
+
+#define TYPE_ICC_BUS "icc-bus"
+
+#ifndef CONFIG_USER_ONLY
+typedef struct ICCBus {
+    BusState qbus;
+} ICCBus;
+#define ICC_BUS(obj) OBJECT_CHECK(ICCBus, (obj), TYPE_ICC_BUS)
+
+typedef struct ICCDevice {
+    DeviceState qdev;
+} ICCDevice;
+
+typedef struct ICCDeviceClass {
+    DeviceClass parent_class;
+    int (*init)(ICCDevice *dev);
+} ICCDeviceClass;
+#define TYPE_ICC_DEVICE "icc-device"
+#define ICC_DEVICE(obj) OBJECT_CHECK(ICCDevice, (obj), TYPE_ICC_DEVICE)
+#define ICC_DEVICE_CLASS(klass) \
+     OBJECT_CLASS_CHECK(ICCDeviceClass, (klass), TYPE_ICC_DEVICE)
+#define ICC_DEVICE_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(ICCDeviceClass, (obj), TYPE_ICC_DEVICE)
+
+#define TYPE_ICC_BRIDGE "icc-bridge"
+
+#endif /* CONFIG_USER_ONLY */
+#endif