Citrix PV Bus device

diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
index 205d22e..8e28831 100644
--- a/hw/i386/Makefile.objs
+++ b/hw/i386/Makefile.objs
@@ -4,3 +4,4 @@  obj-y += pc.o pc_piix.o pc_q35.o
 obj-$(CONFIG_XEN) += xen_domainbuild.o xen_machine_pv.o
 
 obj-y += kvmvapic.o
+obj-y += citrix_pv_bus.o
diff --git a/hw/i386/citrix_pv_bus.c b/hw/i386/citrix_pv_bus.c
new file mode 100644
index 0000000..c17cfa6
--- /dev/null
+++ b/hw/i386/citrix_pv_bus.c
@@ -0,0 +1,126 @@ 
+/* Copyright (c) Citrix Systems Inc.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, 
+ * with or without modification, are permitted provided 
+ * that the following conditions are met:
+ * 
+ * *   Redistributions of source code must retain the above 
+ *     copyright notice, this list of conditions and the 
+ *     following disclaimer.
+ * *   Redistributions in binary form must reproduce the above 
+ *     copyright notice, this list of conditions and the 
+ *     following disclaimer in the documentation and/or other 
+ *     materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
+ * SUCH DAMAGE.
+ */
+
+#include "hw/hw.h"
+#include "hw/pci/pci.h"
+#include "trace.h"
+
+#define TYPE_CITRIX_PV_BUS_DEVICE  "citrix-pv"
+
+#define CITRIX_PV_BUS_DEVICE(obj) \
+     OBJECT_CHECK(CitrixPVBusDevice, (obj), TYPE_CITRIX_PV_BUS_DEVICE)
+
+typedef struct CitrixPVBusDevice {
+    /*< private >*/
+    PCIDevice       parent_obj;
+    /*< public >*/
+    uint8_t         revision;
+    uint32_t        size;
+    MemoryRegion    mmio;
+} CitrixPVBusDevice;
+
+static uint64_t citrix_pv_bus_mmio_read(void *opaque, hwaddr addr,
+                                        unsigned size)
+{
+    trace_citrix_pv_bus_mmio_read(addr);
+
+    return ~(uint64_t)0;
+}
+
+static void citrix_pv_bus_mmio_write(void *opaque, hwaddr addr,
+                                     uint64_t val, unsigned size)
+{
+    trace_citrix_pv_bus_mmio_write(addr);
+}
+
+static const MemoryRegionOps citrix_pv_bus_mmio_ops = {
+    .read = &citrix_pv_bus_mmio_read,
+    .write = &citrix_pv_bus_mmio_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static int citrix_pv_bus_init(PCIDevice *pci_dev)
+{
+    CitrixPVBusDevice *d = CITRIX_PV_BUS_DEVICE(pci_dev);
+    uint8_t *pci_conf;
+
+    pci_conf = pci_dev->config;
+
+    pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_MEMORY);
+    pci_set_byte(pci_conf + PCI_REVISION_ID, d->revision);
+
+    pci_config_set_prog_interface(pci_conf, 0);
+
+    pci_conf[PCI_INTERRUPT_PIN] = 1;
+
+    memory_region_init_io(&d->mmio, &citrix_pv_bus_mmio_ops, d,
+                          "citrix-bus-mmio", d->size);
+
+    pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
+                     &d->mmio);
+
+    return 0;
+}
+
+static Property citrix_pv_bus_props[] = {
+    DEFINE_PROP_UINT8("revision", CitrixPVBusDevice, revision, 0x01),
+    DEFINE_PROP_UINT32("size", CitrixPVBusDevice, size, 0x400000),
+    DEFINE_PROP_END_OF_LIST()
+};
+
+static void citrix_pv_bus_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->init = citrix_pv_bus_init;
+    k->vendor_id = PCI_VENDOR_ID_CITRIX;
+    k->device_id = PCI_DEVICE_ID_CITRIX_PV_BUS;
+    k->class_id = PCI_CLASS_SYSTEM_OTHER;
+    k->subsystem_vendor_id = PCI_VENDOR_ID_CITRIX;
+    k->subsystem_id = PCI_DEVICE_ID_CITRIX_PV_BUS;
+    dc->desc = "Citrix PV Bus";
+    dc->props = citrix_pv_bus_props;
+}
+
+static const TypeInfo citrix_pv_bus_type_info = {
+    .name          = TYPE_CITRIX_PV_BUS_DEVICE,
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(CitrixPVBusDevice),
+    .class_init    = citrix_pv_bus_class_init,
+};
+
+static void citrix_pv_bus_register_types(void)
+{
+    type_register_static(&citrix_pv_bus_type_info);
+}
+
+type_init(citrix_pv_bus_register_types)
diff --git a/include/hw/pci/pci_ids.h b/include/hw/pci/pci_ids.h
index d8dc2f1..95b236f 100644
--- a/include/hw/pci/pci_ids.h
+++ b/include/hw/pci/pci_ids.h
@@ -142,8 +142,11 @@ 
 
 #define PCI_DEVICE_ID_INTEL_Q35_MCH      0x29c0
 
-#define PCI_VENDOR_ID_XEN               0x5853
-#define PCI_DEVICE_ID_XEN_PLATFORM      0x0001
+#define PCI_VENDOR_ID_CITRIX             0x5853
+#define PCI_DEVICE_ID_CITRIX_PV_BUS      0x0002
+
+#define PCI_VENDOR_ID_XEN                (PCI_VENDOR_ID_CITRIX)
+#define PCI_DEVICE_ID_XEN_PLATFORM       0x0001
 
 #define PCI_VENDOR_ID_NEC                0x1033
 #define PCI_DEVICE_ID_NEC_UPD720200      0x0194
diff --git a/trace-events b/trace-events
index c5f1ccb..63052b9 100644
--- a/trace-events
+++ b/trace-events
@@ -1161,3 +1161,7 @@  kvm_run_exit(int cpu_index, uint32_t reason) "cpu_index %d, reason %d"
 # qom/object.c
 object_dynamic_cast_assert(const char *type, const char *target, const char *file, int line, const char *func) "%s->%s (%s:%d:%s)"
 object_class_dynamic_cast_assert(const char *type, const char *target, const char *file, int line, const char *func) "%s->%s (%s:%d:%s)"
+
+# hw/i386/citrix_pv_bus.c
+citrix_pv_bus_mmio_read(uint64_t addr) "WARNING: read from Citrix PV MMIO space (address %"PRIx64")"
+citrix_pv_bus_mmio_write(uint64_t addr) "WARNING: write to Citrix PV MMIO space (address %"PRIx64")"