hw/isa/piix3.c - qemu - Git at Google

 /*
  * QEMU PIIX PCI ISA Bridge Emulation
  *
  * Copyright (c) 2006 Fabrice Bellard
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include "qemu/osdep.h"
 #include "qemu/range.h"
 #include "qapi/error.h"
 #include "hw/dma/i8257.h"
 #include "hw/southbridge/piix.h"
 #include "hw/irq.h"
 #include "hw/isa/isa.h"
 #include "hw/xen/xen.h"
 #include "sysemu/runstate.h"
 #include "migration/vmstate.h"
 #include "hw/acpi/acpi_aml_interface.h"

 #define XEN_PIIX_NUM_PIRQS      128ULL

 static void piix3_set_irq_pic(PIIX3State *piix3, int pic_irq)
 {
     qemu_set_irq(piix3->pic[pic_irq],
                  !!(piix3->pic_levels &
                     (((1ULL << PIIX_NUM_PIRQS) - 1) <<
                      (pic_irq * PIIX_NUM_PIRQS))));
 }

 static void piix3_set_irq_level_internal(PIIX3State *piix3, int pirq, int level)
 {
     int pic_irq;
     uint64_t mask;

     pic_irq = piix3->dev.config[PIIX_PIRQCA + pirq];
     if (pic_irq >= PIIX_NUM_PIC_IRQS) {
         return;
     }

     mask = 1ULL << ((pic_irq * PIIX_NUM_PIRQS) + pirq);
     piix3->pic_levels &= ~mask;
     piix3->pic_levels |= mask * !!level;
 }

 static void piix3_set_irq_level(PIIX3State *piix3, int pirq, int level)
 {
     int pic_irq;

     pic_irq = piix3->dev.config[PIIX_PIRQCA + pirq];
     if (pic_irq >= PIIX_NUM_PIC_IRQS) {
         return;
     }

     piix3_set_irq_level_internal(piix3, pirq, level);

     piix3_set_irq_pic(piix3, pic_irq);
 }

 static void piix3_set_irq(void *opaque, int pirq, int level)
 {
     PIIX3State *piix3 = opaque;
     piix3_set_irq_level(piix3, pirq, level);
 }

 /*
  * Return the global irq number corresponding to a given device irq
  * pin. We could also use the bus number to have a more precise mapping.
  */
 static int pci_slot_get_pirq(PCIDevice *pci_dev, int pci_intx)
 {
     int slot_addend;
     slot_addend = PCI_SLOT(pci_dev->devfn) - 1;
     return (pci_intx + slot_addend) & 3;
 }

 static PCIINTxRoute piix3_route_intx_pin_to_irq(void *opaque, int pin)
 {
     PIIX3State *piix3 = opaque;
     int irq = piix3->dev.config[PIIX_PIRQCA + pin];
     PCIINTxRoute route;

     if (irq < PIIX_NUM_PIC_IRQS) {
         route.mode = PCI_INTX_ENABLED;
         route.irq = irq;
     } else {
         route.mode = PCI_INTX_DISABLED;
         route.irq = -1;
     }
     return route;
 }

 /* irq routing is changed. so rebuild bitmap */
 static void piix3_update_irq_levels(PIIX3State *piix3)
 {
     PCIBus *bus = pci_get_bus(&piix3->dev);
     int pirq;

     piix3->pic_levels = 0;
     for (pirq = 0; pirq < PIIX_NUM_PIRQS; pirq++) {
         piix3_set_irq_level(piix3, pirq, pci_bus_get_irq_level(bus, pirq));
     }
 }

 static void piix3_write_config(PCIDevice *dev,
                                uint32_t address, uint32_t val, int len)
 {
     pci_default_write_config(dev, address, val, len);
     if (ranges_overlap(address, len, PIIX_PIRQCA, 4)) {
         PIIX3State *piix3 = PIIX3_PCI_DEVICE(dev);
         int pic_irq;

         pci_bus_fire_intx_routing_notifier(pci_get_bus(&piix3->dev));
         piix3_update_irq_levels(piix3);
         for (pic_irq = 0; pic_irq < PIIX_NUM_PIC_IRQS; pic_irq++) {
             piix3_set_irq_pic(piix3, pic_irq);
         }
     }
 }

 static void piix3_write_config_xen(PCIDevice *dev,
                                    uint32_t address, uint32_t val, int len)
 {
     int i;

     /* Scan for updates to PCI link routes (0x60-0x63). */
     for (i = 0; i < len; i++) {
         uint8_t v = (val >> (8 * i)) & 0xff;
         if (v & 0x80) {
             v = 0;
         }
         v &= 0xf;
         if (((address + i) >= PIIX_PIRQCA) && ((address + i) <= PIIX_PIRQCD)) {
             xen_set_pci_link_route(address + i - PIIX_PIRQCA, v);
         }
     }

     piix3_write_config(dev, address, val, len);
 }

 static void piix3_reset(DeviceState *dev)
 {
     PIIX3State *d = PIIX3_PCI_DEVICE(dev);
     uint8_t *pci_conf = d->dev.config;

     pci_conf[0x04] = 0x07; /* master, memory and I/O */
     pci_conf[0x05] = 0x00;
     pci_conf[0x06] = 0x00;
     pci_conf[0x07] = 0x02; /* PCI_status_devsel_medium */
     pci_conf[0x4c] = 0x4d;
     pci_conf[0x4e] = 0x03;
     pci_conf[0x4f] = 0x00;
     pci_conf[0x60] = 0x80;
     pci_conf[0x61] = 0x80;
     pci_conf[0x62] = 0x80;
     pci_conf[0x63] = 0x80;
     pci_conf[0x69] = 0x02;
     pci_conf[0x70] = 0x80;
     pci_conf[0x76] = 0x0c;
     pci_conf[0x77] = 0x0c;
     pci_conf[0x78] = 0x02;
     pci_conf[0x79] = 0x00;
     pci_conf[0x80] = 0x00;
     pci_conf[0x82] = 0x00;
     pci_conf[0xa0] = 0x08;
     pci_conf[0xa2] = 0x00;
     pci_conf[0xa3] = 0x00;
     pci_conf[0xa4] = 0x00;
     pci_conf[0xa5] = 0x00;
     pci_conf[0xa6] = 0x00;
     pci_conf[0xa7] = 0x00;
     pci_conf[0xa8] = 0x0f;
     pci_conf[0xaa] = 0x00;
     pci_conf[0xab] = 0x00;
     pci_conf[0xac] = 0x00;
     pci_conf[0xae] = 0x00;

     d->pic_levels = 0;
     d->rcr = 0;
 }

 static int piix3_post_load(void *opaque, int version_id)
 {
     PIIX3State *piix3 = opaque;
     int pirq;

     /*
      * Because the i8259 has not been deserialized yet, qemu_irq_raise
      * might bring the system to a different state than the saved one;
      * for example, the interrupt could be masked but the i8259 would
      * not know that yet and would trigger an interrupt in the CPU.
      *
      * Here, we update irq levels without raising the interrupt.
      * Interrupt state will be deserialized separately through the i8259.
      */
     piix3->pic_levels = 0;
     for (pirq = 0; pirq < PIIX_NUM_PIRQS; pirq++) {
         piix3_set_irq_level_internal(piix3, pirq,
             pci_bus_get_irq_level(pci_get_bus(&piix3->dev), pirq));
     }
     return 0;
 }

 static int piix3_pre_save(void *opaque)
 {
     int i;
     PIIX3State *piix3 = opaque;

     for (i = 0; i < ARRAY_SIZE(piix3->pci_irq_levels_vmstate); i++) {
         piix3->pci_irq_levels_vmstate[i] =
             pci_bus_get_irq_level(pci_get_bus(&piix3->dev), i);
     }

     return 0;
 }

 static bool piix3_rcr_needed(void *opaque)
 {
     PIIX3State *piix3 = opaque;

     return (piix3->rcr != 0);
 }

 static const VMStateDescription vmstate_piix3_rcr = {
     .name = "PIIX3/rcr",
     .version_id = 1,
     .minimum_version_id = 1,
     .needed = piix3_rcr_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(rcr, PIIX3State),
         VMSTATE_END_OF_LIST()
     }
 };

 static const VMStateDescription vmstate_piix3 = {
     .name = "PIIX3",
     .version_id = 3,
     .minimum_version_id = 2,
     .post_load = piix3_post_load,
     .pre_save = piix3_pre_save,
     .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(dev, PIIX3State),
         VMSTATE_INT32_ARRAY_V(pci_irq_levels_vmstate, PIIX3State,
                               PIIX_NUM_PIRQS, 3),
         VMSTATE_END_OF_LIST()
     },
     .subsections = (const VMStateDescription*[]) {
         &vmstate_piix3_rcr,
         NULL
     }
 };


 static void rcr_write(void *opaque, hwaddr addr, uint64_t val, unsigned len)
 {
     PIIX3State *d = opaque;

     if (val & 4) {
         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
         return;
     }
     d->rcr = val & 2; /* keep System Reset type only */
 }

 static uint64_t rcr_read(void *opaque, hwaddr addr, unsigned len)
 {
     PIIX3State *d = opaque;

     return d->rcr;
 }

 static const MemoryRegionOps rcr_ops = {
     .read = rcr_read,
     .write = rcr_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
     .impl = {
         .min_access_size = 1,
         .max_access_size = 1,
     },
 };

 static void pci_piix3_realize(PCIDevice *dev, Error **errp)
 {
     PIIX3State *d = PIIX3_PCI_DEVICE(dev);
     ISABus *isa_bus;

     isa_bus = isa_bus_new(DEVICE(d), pci_address_space(dev),
                           pci_address_space_io(dev), errp);
     if (!isa_bus) {
         return;
     }

     memory_region_init_io(&d->rcr_mem, OBJECT(dev), &rcr_ops, d,
                           "piix3-reset-control", 1);
     memory_region_add_subregion_overlap(pci_address_space_io(dev),
                                         PIIX_RCR_IOPORT, &d->rcr_mem, 1);

     i8257_dma_init(isa_bus, 0);
 }

 static void build_pci_isa_aml(AcpiDevAmlIf *adev, Aml *scope)
 {
     BusChild *kid;
     BusState *bus = qdev_get_child_bus(DEVICE(adev), "isa.0");

     /* PIIX PCI to ISA irq remapping */
     aml_append(scope, aml_operation_region("P40C", AML_PCI_CONFIG,
                                          aml_int(0x60), 0x04));
     QTAILQ_FOREACH(kid, &bus->children, sibling) {
         call_dev_aml_func(DEVICE(kid->child), scope);
     }
 }

 static void pci_piix3_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
     AcpiDevAmlIfClass *adevc = ACPI_DEV_AML_IF_CLASS(klass);

     dc->reset       = piix3_reset;
     dc->desc        = "ISA bridge";
     dc->vmsd        = &vmstate_piix3;
     dc->hotpluggable   = false;
     k->vendor_id    = PCI_VENDOR_ID_INTEL;
     /* 82371SB PIIX3 PCI-to-ISA bridge (Step A1) */
     k->device_id    = PCI_DEVICE_ID_INTEL_82371SB_0;
     k->class_id     = PCI_CLASS_BRIDGE_ISA;
     /*
      * Reason: part of PIIX3 southbridge, needs to be wired up by
      * pc_piix.c's pc_init1()
      */
     dc->user_creatable = false;
     adevc->build_dev_aml = build_pci_isa_aml;
 }

 static const TypeInfo piix3_pci_type_info = {
     .name = TYPE_PIIX3_PCI_DEVICE,
     .parent = TYPE_PCI_DEVICE,
     .instance_size = sizeof(PIIX3State),
     .abstract = true,
     .class_init = pci_piix3_class_init,
     .interfaces = (InterfaceInfo[]) {
         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
         { TYPE_ACPI_DEV_AML_IF },
         { },
     },
 };

 static void piix3_realize(PCIDevice *dev, Error **errp)
 {
     ERRP_GUARD();
     PIIX3State *piix3 = PIIX3_PCI_DEVICE(dev);
     PCIBus *pci_bus = pci_get_bus(dev);

     pci_piix3_realize(dev, errp);
     if (*errp) {
         return;
     }

     pci_bus_irqs(pci_bus, piix3_set_irq, pci_slot_get_pirq,
                  piix3, PIIX_NUM_PIRQS);
     pci_bus_set_route_irq_fn(pci_bus, piix3_route_intx_pin_to_irq);
 }

 static void piix3_class_init(ObjectClass *klass, void *data)
 {
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);

     k->config_write = piix3_write_config;
     k->realize = piix3_realize;
 }

 static const TypeInfo piix3_info = {
     .name          = TYPE_PIIX3_DEVICE,
     .parent        = TYPE_PIIX3_PCI_DEVICE,
     .class_init    = piix3_class_init,
 };

 static void piix3_xen_realize(PCIDevice *dev, Error **errp)
 {
     ERRP_GUARD();
     PIIX3State *piix3 = PIIX3_PCI_DEVICE(dev);
     PCIBus *pci_bus = pci_get_bus(dev);

     pci_piix3_realize(dev, errp);
     if (*errp) {
         return;
     }

     /*
      * Xen supports additional interrupt routes from the PCI devices to
      * the IOAPIC: the four pins of each PCI device on the bus are also
      * connected to the IOAPIC directly.
      * These additional routes can be discovered through ACPI.
      */
     pci_bus_irqs(pci_bus, xen_piix3_set_irq, xen_pci_slot_get_pirq,
                  piix3, XEN_PIIX_NUM_PIRQS);
 }

 static void piix3_xen_class_init(ObjectClass *klass, void *data)
 {
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);

     k->config_write = piix3_write_config_xen;
     k->realize = piix3_xen_realize;
 }

 static const TypeInfo piix3_xen_info = {
     .name          = TYPE_PIIX3_XEN_DEVICE,
     .parent        = TYPE_PIIX3_PCI_DEVICE,
     .class_init    = piix3_xen_class_init,
 };

 static void piix3_register_types(void)
 {
     type_register_static(&piix3_pci_type_info);
     type_register_static(&piix3_info);
     type_register_static(&piix3_xen_info);
 }

 type_init(piix3_register_types)
	/*
	* QEMU PIIX PCI ISA Bridge Emulation
	*
	* Copyright (c) 2006 Fabrice Bellard
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include "qemu/osdep.h"
	#include "qemu/range.h"
	#include "qapi/error.h"
	#include "hw/dma/i8257.h"
	#include "hw/southbridge/piix.h"
	#include "hw/irq.h"
	#include "hw/isa/isa.h"
	#include "hw/xen/xen.h"
	#include "sysemu/runstate.h"
	#include "migration/vmstate.h"
	#include "hw/acpi/acpi_aml_interface.h"

	#define XEN_PIIX_NUM_PIRQS 128ULL

	static void piix3_set_irq_pic(PIIX3State *piix3, int pic_irq)
	{
	qemu_set_irq(piix3->pic[pic_irq],
	!!(piix3->pic_levels &
	(((1ULL << PIIX_NUM_PIRQS) - 1) <<
	(pic_irq * PIIX_NUM_PIRQS))));
	}

	static void piix3_set_irq_level_internal(PIIX3State *piix3, int pirq, int level)
	{
	int pic_irq;
	uint64_t mask;

	pic_irq = piix3->dev.config[PIIX_PIRQCA + pirq];
	if (pic_irq >= PIIX_NUM_PIC_IRQS) {
	return;
	}

	mask = 1ULL << ((pic_irq * PIIX_NUM_PIRQS) + pirq);
	piix3->pic_levels &= ~mask;
	piix3->pic_levels \|= mask * !!level;
	}

	static void piix3_set_irq_level(PIIX3State *piix3, int pirq, int level)
	{
	int pic_irq;

	pic_irq = piix3->dev.config[PIIX_PIRQCA + pirq];
	if (pic_irq >= PIIX_NUM_PIC_IRQS) {
	return;
	}

	piix3_set_irq_level_internal(piix3, pirq, level);

	piix3_set_irq_pic(piix3, pic_irq);
	}

	static void piix3_set_irq(void *opaque, int pirq, int level)
	{
	PIIX3State *piix3 = opaque;
	piix3_set_irq_level(piix3, pirq, level);
	}

	/*
	* Return the global irq number corresponding to a given device irq
	* pin. We could also use the bus number to have a more precise mapping.
	*/
	static int pci_slot_get_pirq(PCIDevice *pci_dev, int pci_intx)
	{
	int slot_addend;
	slot_addend = PCI_SLOT(pci_dev->devfn) - 1;
	return (pci_intx + slot_addend) & 3;
	}

	static PCIINTxRoute piix3_route_intx_pin_to_irq(void *opaque, int pin)
	{
	PIIX3State *piix3 = opaque;
	int irq = piix3->dev.config[PIIX_PIRQCA + pin];
	PCIINTxRoute route;

	if (irq < PIIX_NUM_PIC_IRQS) {
	route.mode = PCI_INTX_ENABLED;
	route.irq = irq;
	} else {
	route.mode = PCI_INTX_DISABLED;
	route.irq = -1;
	}
	return route;
	}

	/* irq routing is changed. so rebuild bitmap */
	static void piix3_update_irq_levels(PIIX3State *piix3)
	{
	PCIBus *bus = pci_get_bus(&piix3->dev);
	int pirq;

	piix3->pic_levels = 0;
	for (pirq = 0; pirq < PIIX_NUM_PIRQS; pirq++) {
	piix3_set_irq_level(piix3, pirq, pci_bus_get_irq_level(bus, pirq));
	}
	}

	static void piix3_write_config(PCIDevice *dev,
	uint32_t address, uint32_t val, int len)
	{
	pci_default_write_config(dev, address, val, len);
	if (ranges_overlap(address, len, PIIX_PIRQCA, 4)) {
	PIIX3State *piix3 = PIIX3_PCI_DEVICE(dev);
	int pic_irq;

	pci_bus_fire_intx_routing_notifier(pci_get_bus(&piix3->dev));
	piix3_update_irq_levels(piix3);
	for (pic_irq = 0; pic_irq < PIIX_NUM_PIC_IRQS; pic_irq++) {
	piix3_set_irq_pic(piix3, pic_irq);
	}
	}
	}

	static void piix3_write_config_xen(PCIDevice *dev,
	uint32_t address, uint32_t val, int len)
	{
	int i;

	/* Scan for updates to PCI link routes (0x60-0x63). */
	for (i = 0; i < len; i++) {
	uint8_t v = (val >> (8 * i)) & 0xff;
	if (v & 0x80) {
	v = 0;
	}
	v &= 0xf;
	if (((address + i) >= PIIX_PIRQCA) && ((address + i) <= PIIX_PIRQCD)) {
	xen_set_pci_link_route(address + i - PIIX_PIRQCA, v);
	}
	}

	piix3_write_config(dev, address, val, len);
	}

	static void piix3_reset(DeviceState *dev)
	{
	PIIX3State *d = PIIX3_PCI_DEVICE(dev);
	uint8_t *pci_conf = d->dev.config;

	pci_conf[0x04] = 0x07; /* master, memory and I/O */
	pci_conf[0x05] = 0x00;
	pci_conf[0x06] = 0x00;
	pci_conf[0x07] = 0x02; /* PCI_status_devsel_medium */
	pci_conf[0x4c] = 0x4d;
	pci_conf[0x4e] = 0x03;
	pci_conf[0x4f] = 0x00;
	pci_conf[0x60] = 0x80;
	pci_conf[0x61] = 0x80;
	pci_conf[0x62] = 0x80;
	pci_conf[0x63] = 0x80;
	pci_conf[0x69] = 0x02;
	pci_conf[0x70] = 0x80;
	pci_conf[0x76] = 0x0c;
	pci_conf[0x77] = 0x0c;
	pci_conf[0x78] = 0x02;
	pci_conf[0x79] = 0x00;
	pci_conf[0x80] = 0x00;
	pci_conf[0x82] = 0x00;
	pci_conf[0xa0] = 0x08;
	pci_conf[0xa2] = 0x00;
	pci_conf[0xa3] = 0x00;
	pci_conf[0xa4] = 0x00;
	pci_conf[0xa5] = 0x00;
	pci_conf[0xa6] = 0x00;
	pci_conf[0xa7] = 0x00;
	pci_conf[0xa8] = 0x0f;
	pci_conf[0xaa] = 0x00;
	pci_conf[0xab] = 0x00;
	pci_conf[0xac] = 0x00;
	pci_conf[0xae] = 0x00;

	d->pic_levels = 0;
	d->rcr = 0;
	}

	static int piix3_post_load(void *opaque, int version_id)
	{
	PIIX3State *piix3 = opaque;
	int pirq;

	/*
	* Because the i8259 has not been deserialized yet, qemu_irq_raise
	* might bring the system to a different state than the saved one;
	* for example, the interrupt could be masked but the i8259 would
	* not know that yet and would trigger an interrupt in the CPU.
	*
	* Here, we update irq levels without raising the interrupt.
	* Interrupt state will be deserialized separately through the i8259.
	*/
	piix3->pic_levels = 0;
	for (pirq = 0; pirq < PIIX_NUM_PIRQS; pirq++) {
	piix3_set_irq_level_internal(piix3, pirq,
	pci_bus_get_irq_level(pci_get_bus(&piix3->dev), pirq));
	}
	return 0;
	}

	static int piix3_pre_save(void *opaque)
	{
	int i;
	PIIX3State *piix3 = opaque;

	for (i = 0; i < ARRAY_SIZE(piix3->pci_irq_levels_vmstate); i++) {
	piix3->pci_irq_levels_vmstate[i] =
	pci_bus_get_irq_level(pci_get_bus(&piix3->dev), i);
	}

	return 0;
	}

	static bool piix3_rcr_needed(void *opaque)
	{
	PIIX3State *piix3 = opaque;

	return (piix3->rcr != 0);
	}

	static const VMStateDescription vmstate_piix3_rcr = {
	.name = "PIIX3/rcr",
	.version_id = 1,
	.minimum_version_id = 1,
	.needed = piix3_rcr_needed,
	.fields = (VMStateField[]) {
	VMSTATE_UINT8(rcr, PIIX3State),
	VMSTATE_END_OF_LIST()
	}
	};

	static const VMStateDescription vmstate_piix3 = {
	.name = "PIIX3",
	.version_id = 3,
	.minimum_version_id = 2,
	.post_load = piix3_post_load,
	.pre_save = piix3_pre_save,
	.fields = (VMStateField[]) {
	VMSTATE_PCI_DEVICE(dev, PIIX3State),
	VMSTATE_INT32_ARRAY_V(pci_irq_levels_vmstate, PIIX3State,
	PIIX_NUM_PIRQS, 3),
	VMSTATE_END_OF_LIST()
	},
	.subsections = (const VMStateDescription*[]) {
	&vmstate_piix3_rcr,
	NULL
	}
	};


	static void rcr_write(void *opaque, hwaddr addr, uint64_t val, unsigned len)
	{
	PIIX3State *d = opaque;

	if (val & 4) {
	qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
	return;
	}
	d->rcr = val & 2; /* keep System Reset type only */
	}

	static uint64_t rcr_read(void *opaque, hwaddr addr, unsigned len)
	{
	PIIX3State *d = opaque;

	return d->rcr;
	}

	static const MemoryRegionOps rcr_ops = {
	.read = rcr_read,
	.write = rcr_write,
	.endianness = DEVICE_LITTLE_ENDIAN,
	.impl = {
	.min_access_size = 1,
	.max_access_size = 1,
	},
	};

	static void pci_piix3_realize(PCIDevice dev, Error *errp)
	{
	PIIX3State *d = PIIX3_PCI_DEVICE(dev);
	ISABus *isa_bus;

	isa_bus = isa_bus_new(DEVICE(d), pci_address_space(dev),
	pci_address_space_io(dev), errp);
	if (!isa_bus) {
	return;
	}

	memory_region_init_io(&d->rcr_mem, OBJECT(dev), &rcr_ops, d,
	"piix3-reset-control", 1);
	memory_region_add_subregion_overlap(pci_address_space_io(dev),
	PIIX_RCR_IOPORT, &d->rcr_mem, 1);

	i8257_dma_init(isa_bus, 0);
	}

	static void build_pci_isa_aml(AcpiDevAmlIf adev, Aml scope)
	{
	BusChild *kid;
	BusState *bus = qdev_get_child_bus(DEVICE(adev), "isa.0");

	/* PIIX PCI to ISA irq remapping */
	aml_append(scope, aml_operation_region("P40C", AML_PCI_CONFIG,
	aml_int(0x60), 0x04));
	QTAILQ_FOREACH(kid, &bus->children, sibling) {
	call_dev_aml_func(DEVICE(kid->child), scope);
	}
	}

	static void pci_piix3_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
	AcpiDevAmlIfClass *adevc = ACPI_DEV_AML_IF_CLASS(klass);

	dc->reset = piix3_reset;
	dc->desc = "ISA bridge";
	dc->vmsd = &vmstate_piix3;
	dc->hotpluggable = false;
	k->vendor_id = PCI_VENDOR_ID_INTEL;
	/* 82371SB PIIX3 PCI-to-ISA bridge (Step A1) */
	k->device_id = PCI_DEVICE_ID_INTEL_82371SB_0;
	k->class_id = PCI_CLASS_BRIDGE_ISA;
	/*
	* Reason: part of PIIX3 southbridge, needs to be wired up by
	* pc_piix.c's pc_init1()
	*/
	dc->user_creatable = false;
	adevc->build_dev_aml = build_pci_isa_aml;
	}

	static const TypeInfo piix3_pci_type_info = {
	.name = TYPE_PIIX3_PCI_DEVICE,
	.parent = TYPE_PCI_DEVICE,
	.instance_size = sizeof(PIIX3State),
	.abstract = true,
	.class_init = pci_piix3_class_init,
	.interfaces = (InterfaceInfo[]) {
	{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
	{ TYPE_ACPI_DEV_AML_IF },
	{ },
	},
	};

	static void piix3_realize(PCIDevice dev, Error *errp)
	{
	ERRP_GUARD();
	PIIX3State *piix3 = PIIX3_PCI_DEVICE(dev);
	PCIBus *pci_bus = pci_get_bus(dev);

	pci_piix3_realize(dev, errp);
	if (*errp) {
	return;
	}

	pci_bus_irqs(pci_bus, piix3_set_irq, pci_slot_get_pirq,
	piix3, PIIX_NUM_PIRQS);
	pci_bus_set_route_irq_fn(pci_bus, piix3_route_intx_pin_to_irq);
	}

	static void piix3_class_init(ObjectClass klass, void data)
	{
	PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);

	k->config_write = piix3_write_config;
	k->realize = piix3_realize;
	}

	static const TypeInfo piix3_info = {
	.name = TYPE_PIIX3_DEVICE,
	.parent = TYPE_PIIX3_PCI_DEVICE,
	.class_init = piix3_class_init,
	};

	static void piix3_xen_realize(PCIDevice dev, Error *errp)
	{
	ERRP_GUARD();
	PIIX3State *piix3 = PIIX3_PCI_DEVICE(dev);
	PCIBus *pci_bus = pci_get_bus(dev);

	pci_piix3_realize(dev, errp);
	if (*errp) {
	return;
	}

	/*
	* Xen supports additional interrupt routes from the PCI devices to
	* the IOAPIC: the four pins of each PCI device on the bus are also
	* connected to the IOAPIC directly.
	* These additional routes can be discovered through ACPI.
	*/
	pci_bus_irqs(pci_bus, xen_piix3_set_irq, xen_pci_slot_get_pirq,
	piix3, XEN_PIIX_NUM_PIRQS);
	}

	static void piix3_xen_class_init(ObjectClass klass, void data)
	{
	PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);

	k->config_write = piix3_write_config_xen;
	k->realize = piix3_xen_realize;
	}

	static const TypeInfo piix3_xen_info = {
	.name = TYPE_PIIX3_XEN_DEVICE,
	.parent = TYPE_PIIX3_PCI_DEVICE,
	.class_init = piix3_xen_class_init,
	};

	static void piix3_register_types(void)
	{
	type_register_static(&piix3_pci_type_info);
	type_register_static(&piix3_info);
	type_register_static(&piix3_xen_info);
	}

	type_init(piix3_register_types)