hw/i386/xen/xen_platform.c - qemu - Git at Google

 /*
  * XEN platform pci device, formerly known as the event channel device
  *
  * Copyright (c) 2003-2004 Intel Corp.
  * Copyright (c) 2006 XenSource
  *
  * 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 "qapi/error.h"
 #include "hw/ide/pci.h"
 #include "hw/pci/pci.h"
 #include "migration/vmstate.h"
 #include "net/net.h"
 #include "trace.h"
 #include "sysemu/xen.h"
 #include "sysemu/block-backend.h"
 #include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "qom/object.h"

 #ifdef CONFIG_XEN
 #include "hw/xen/xen_native.h"
 #endif

 /* The rule is that xen_native.h must come first */
 #include "hw/xen/xen.h"

 //#define DEBUG_PLATFORM

 #ifdef DEBUG_PLATFORM
 #define DPRINTF(fmt, ...) do { \
     fprintf(stderr, "xen_platform: " fmt, ## __VA_ARGS__); \
 } while (0)
 #else
 #define DPRINTF(fmt, ...) do { } while (0)
 #endif

 #define PFFLAG_ROM_LOCK 1 /* Sets whether ROM memory area is RW or RO */

 struct PCIXenPlatformState {
     /*< private >*/
     PCIDevice parent_obj;
     /*< public >*/

     MemoryRegion fixed_io;
     MemoryRegion bar;
     MemoryRegion mmio_bar;
     uint8_t flags; /* used only for version_id == 2 */
     uint16_t driver_product_version;

     /* Log from guest drivers */
     char log_buffer[4096];
     int log_buffer_off;
 };

 #define TYPE_XEN_PLATFORM "xen-platform"
 OBJECT_DECLARE_SIMPLE_TYPE(PCIXenPlatformState, XEN_PLATFORM)

 #define XEN_PLATFORM_IOPORT 0x10

 /* Send bytes to syslog */
 static void log_writeb(PCIXenPlatformState *s, char val)
 {
     if (val == '\n' || s->log_buffer_off == sizeof(s->log_buffer) - 1) {
         /* Flush buffer */
         s->log_buffer[s->log_buffer_off] = 0;
         trace_xen_platform_log(s->log_buffer);
         s->log_buffer_off = 0;
     } else {
         s->log_buffer[s->log_buffer_off++] = val;
     }
 }

 /*
  * Unplug device flags.
  *
  * The logic got a little confused at some point in the past but this is
  * what they do now.
  *
  * bit 0: Unplug all IDE and SCSI disks.
  * bit 1: Unplug all NICs.
  * bit 2: Unplug IDE disks except primary master. This is overridden if
  *        bit 0 is also present in the mask.
  * bit 3: Unplug all NVMe disks.
  *
  */
 #define _UNPLUG_IDE_SCSI_DISKS 0
 #define UNPLUG_IDE_SCSI_DISKS (1u << _UNPLUG_IDE_SCSI_DISKS)

 #define _UNPLUG_ALL_NICS 1
 #define UNPLUG_ALL_NICS (1u << _UNPLUG_ALL_NICS)

 #define _UNPLUG_AUX_IDE_DISKS 2
 #define UNPLUG_AUX_IDE_DISKS (1u << _UNPLUG_AUX_IDE_DISKS)

 #define _UNPLUG_NVME_DISKS 3
 #define UNPLUG_NVME_DISKS (1u << _UNPLUG_NVME_DISKS)

 static bool pci_device_is_passthrough(PCIDevice *d)
 {
     if (!strcmp(d->name, "xen-pci-passthrough")) {
         return true;
     }

     if (xen_mode == XEN_EMULATE && !strcmp(d->name, "vfio-pci")) {
         return true;
     }

     return false;
 }

 static void unplug_nic(PCIBus *b, PCIDevice *d, void *o)
 {
     /* We have to ignore passthrough devices */
     if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
             PCI_CLASS_NETWORK_ETHERNET
             && !pci_device_is_passthrough(d)) {
         object_unparent(OBJECT(d));
     }
 }

 /* Remove the peer of the NIC device. Normally, this would be a tap device. */
 static void del_nic_peer(NICState *nic, void *opaque)
 {
     NetClientState *nc;

     nc = qemu_get_queue(nic);
     if (nc->peer)
         qemu_del_net_client(nc->peer);
 }

 static void pci_unplug_nics(PCIBus *bus)
 {
     qemu_foreach_nic(del_nic_peer, NULL);
     pci_for_each_device(bus, 0, unplug_nic, NULL);
 }

 /*
  * The Xen HVM unplug protocol [1] specifies a mechanism to allow guests to
  * request unplug of 'aux' disks (which is stated to mean all IDE disks,
  * except the primary master).
  *
  * NOTE: The semantics of what happens if unplug of all disks and 'aux' disks
  *       is simultaneously requested is not clear. The implementation assumes
  *       that an 'all' request overrides an 'aux' request.
  *
  * [1] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/hvm-emulated-unplug.pandoc
  */
 static void pci_xen_ide_unplug(PCIDevice *d, bool aux)
 {
     DeviceState *dev = DEVICE(d);
     PCIIDEState *pci_ide;
     int i;
     IDEDevice *idedev;
     IDEBus *idebus;
     BlockBackend *blk;

     pci_ide = PCI_IDE(dev);

     for (i = aux ? 1 : 0; i < 4; i++) {
         idebus = &pci_ide->bus[i / 2];
         blk = idebus->ifs[i % 2].blk;

         if (blk && idebus->ifs[i % 2].drive_kind != IDE_CD) {
             if (!(i % 2)) {
                 idedev = idebus->master;
             } else {
                 idedev = idebus->slave;
             }

             blk_drain(blk);
             blk_flush(blk);

             blk_detach_dev(blk, DEVICE(idedev));
             idebus->ifs[i % 2].blk = NULL;
             idedev->conf.blk = NULL;
             monitor_remove_blk(blk);
             blk_unref(blk);
         }
     }
     pci_device_reset(d);
 }

 static void unplug_disks(PCIBus *b, PCIDevice *d, void *opaque)
 {
     uint32_t flags = *(uint32_t *)opaque;
     bool aux = (flags & UNPLUG_AUX_IDE_DISKS) &&
         !(flags & UNPLUG_IDE_SCSI_DISKS);

     /* We have to ignore passthrough devices */
     if (pci_device_is_passthrough(d))
         return;

     switch (pci_get_word(d->config + PCI_CLASS_DEVICE)) {
     case PCI_CLASS_STORAGE_IDE:
         pci_xen_ide_unplug(d, aux);
         break;

     case PCI_CLASS_STORAGE_SCSI:
         if (!aux) {
             object_unparent(OBJECT(d));
         }
         break;

     case PCI_CLASS_STORAGE_EXPRESS:
         if (flags & UNPLUG_NVME_DISKS) {
             object_unparent(OBJECT(d));
         }

     default:
         break;
     }
 }

 static void pci_unplug_disks(PCIBus *bus, uint32_t flags)
 {
     pci_for_each_device(bus, 0, unplug_disks, &flags);
 }

 static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
 {
     PCIXenPlatformState *s = opaque;

     switch (addr) {
     case 0: {
         PCIDevice *pci_dev = PCI_DEVICE(s);
         /* Unplug devices. See comment above flag definitions */
         if (val & (UNPLUG_IDE_SCSI_DISKS | UNPLUG_AUX_IDE_DISKS |
                    UNPLUG_NVME_DISKS)) {
             DPRINTF("unplug disks\n");
             pci_unplug_disks(pci_get_bus(pci_dev), val);
         }
         if (val & UNPLUG_ALL_NICS) {
             DPRINTF("unplug nics\n");
             pci_unplug_nics(pci_get_bus(pci_dev));
         }
         break;
     }
     case 2:
         switch (val) {
         case 1:
             DPRINTF("Citrix Windows PV drivers loaded in guest\n");
             break;
         case 0:
             DPRINTF("Guest claimed to be running PV product 0?\n");
             break;
         default:
             DPRINTF("Unknown PV product %d loaded in guest\n", val);
             break;
         }
         s->driver_product_version = val;
         break;
     }
 }

 static void platform_fixed_ioport_writel(void *opaque, uint32_t addr,
                                          uint32_t val)
 {
     switch (addr) {
     case 0:
         /* PV driver version */
         break;
     }
 }

 static void platform_fixed_ioport_writeb(void *opaque, uint32_t addr, uint32_t val)
 {
     PCIXenPlatformState *s = opaque;

     switch (addr) {
     case 0: /* Platform flags */
         if (xen_mode == XEN_EMULATE) {
             /* XX: Use i440gx/q35 PAM setup to do this? */
             s->flags = val & PFFLAG_ROM_LOCK;
 #ifdef CONFIG_XEN
         } else {
             hvmmem_type_t mem_type = (val & PFFLAG_ROM_LOCK) ?
                 HVMMEM_ram_ro : HVMMEM_ram_rw;

             if (xen_set_mem_type(xen_domid, mem_type, 0xc0, 0x40)) {
                 DPRINTF("unable to change ro/rw state of ROM memory area!\n");
             } else {
                 s->flags = val & PFFLAG_ROM_LOCK;
                 DPRINTF("changed ro/rw state of ROM memory area. now is %s state.\n",
                         (mem_type == HVMMEM_ram_ro ? "ro" : "rw"));
             }
 #endif
         }
         break;

     case 2:
         log_writeb(s, val);
         break;
     }
 }

 static uint32_t platform_fixed_ioport_readw(void *opaque, uint32_t addr)
 {
     switch (addr) {
     case 0:
         /* Magic value so that you can identify the interface. */
         return 0x49d2;
     default:
         return 0xffff;
     }
 }

 static uint32_t platform_fixed_ioport_readb(void *opaque, uint32_t addr)
 {
     PCIXenPlatformState *s = opaque;

     switch (addr) {
     case 0:
         /* Platform flags */
         return s->flags;
     case 2:
         /* Version number */
         return 1;
     default:
         return 0xff;
     }
 }

 static void platform_fixed_ioport_reset(void *opaque)
 {
     PCIXenPlatformState *s = opaque;

     platform_fixed_ioport_writeb(s, 0, 0);
 }

 static uint64_t platform_fixed_ioport_read(void *opaque,
                                            hwaddr addr,
                                            unsigned size)
 {
     switch (size) {
     case 1:
         return platform_fixed_ioport_readb(opaque, addr);
     case 2:
         return platform_fixed_ioport_readw(opaque, addr);
     default:
         return -1;
     }
 }

 static void platform_fixed_ioport_write(void *opaque, hwaddr addr,

                                         uint64_t val, unsigned size)
 {
     switch (size) {
     case 1:
         platform_fixed_ioport_writeb(opaque, addr, val);
         break;
     case 2:
         platform_fixed_ioport_writew(opaque, addr, val);
         break;
     case 4:
         platform_fixed_ioport_writel(opaque, addr, val);
         break;
     }
 }


 static const MemoryRegionOps platform_fixed_io_ops = {
     .read = platform_fixed_ioport_read,
     .write = platform_fixed_ioport_write,
     .valid = {
         .unaligned = true,
     },
     .impl = {
         .min_access_size = 1,
         .max_access_size = 4,
         .unaligned = true,
     },
     .endianness = DEVICE_LITTLE_ENDIAN,
 };

 static void platform_fixed_ioport_init(PCIXenPlatformState* s)
 {
     memory_region_init_io(&s->fixed_io, OBJECT(s), &platform_fixed_io_ops, s,
                           "xen-fixed", 16);
     memory_region_add_subregion(get_system_io(), XEN_PLATFORM_IOPORT,
                                 &s->fixed_io);
 }

 /* Xen Platform PCI Device */

 static uint64_t xen_platform_ioport_readb(void *opaque, hwaddr addr,
                                           unsigned int size)
 {
     if (addr == 0) {
         return platform_fixed_ioport_readb(opaque, 0);
     } else {
         return ~0u;
     }
 }

 static void xen_platform_ioport_writeb(void *opaque, hwaddr addr,
                                        uint64_t val, unsigned int size)
 {
     PCIXenPlatformState *s = opaque;
     PCIDevice *pci_dev = PCI_DEVICE(s);

     switch (addr) {
     case 0: /* Platform flags */
         platform_fixed_ioport_writeb(opaque, 0, (uint32_t)val);
         break;
     case 4:
         if (val == 1) {
             /*
              * SUSE unplug for Xenlinux
              * xen-kmp used this since xen-3.0.4, instead the official protocol
              * from xen-3.3+ It did an unconditional "outl(1, (ioaddr + 4));"
              * Pre VMDP 1.7 used 4 and 8 depending on how VMDP was configured.
              * If VMDP was to control both disk and LAN it would use 4.
              * If it controlled just disk or just LAN, it would use 8 below.
              */
             pci_unplug_disks(pci_get_bus(pci_dev), UNPLUG_IDE_SCSI_DISKS);
             pci_unplug_nics(pci_get_bus(pci_dev));
         }
         break;
     case 8:
         switch (val) {
         case 1:
             pci_unplug_disks(pci_get_bus(pci_dev), UNPLUG_IDE_SCSI_DISKS);
             break;
         case 2:
             pci_unplug_nics(pci_get_bus(pci_dev));
             break;
         default:
             log_writeb(s, (uint32_t)val);
             break;
         }
         break;
     default:
         break;
     }
 }

 static const MemoryRegionOps xen_pci_io_ops = {
     .read  = xen_platform_ioport_readb,
     .write = xen_platform_ioport_writeb,
     .impl.min_access_size = 1,
     .impl.max_access_size = 1,
 };

 static void platform_ioport_bar_setup(PCIXenPlatformState *d)
 {
     memory_region_init_io(&d->bar, OBJECT(d), &xen_pci_io_ops, d,
                           "xen-pci", 0x100);
 }

 static uint64_t platform_mmio_read(void *opaque, hwaddr addr,
                                    unsigned size)
 {
     DPRINTF("Warning: attempted read from physical address "
             "0x" HWADDR_FMT_plx " in xen platform mmio space\n", addr);

     return 0;
 }

 static void platform_mmio_write(void *opaque, hwaddr addr,
                                 uint64_t val, unsigned size)
 {
     DPRINTF("Warning: attempted write of 0x%"PRIx64" to physical "
             "address 0x" HWADDR_FMT_plx " in xen platform mmio space\n",
             val, addr);
 }

 static const MemoryRegionOps platform_mmio_handler = {
     .read = &platform_mmio_read,
     .write = &platform_mmio_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };

 static void platform_mmio_setup(PCIXenPlatformState *d)
 {
     memory_region_init_io(&d->mmio_bar, OBJECT(d), &platform_mmio_handler, d,
                           "xen-mmio", 0x1000000);
 }

 static int xen_platform_post_load(void *opaque, int version_id)
 {
     PCIXenPlatformState *s = opaque;

     platform_fixed_ioport_writeb(s, 0, s->flags);

     return 0;
 }

 static const VMStateDescription vmstate_xen_platform = {
     .name = "platform",
     .version_id = 4,
     .minimum_version_id = 4,
     .post_load = xen_platform_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(parent_obj, PCIXenPlatformState),
         VMSTATE_UINT8(flags, PCIXenPlatformState),
         VMSTATE_END_OF_LIST()
     }
 };

 static void xen_platform_realize(PCIDevice *dev, Error **errp)
 {
     PCIXenPlatformState *d = XEN_PLATFORM(dev);
     uint8_t *pci_conf;

     /* Device will crash on reset if xen is not initialized */
     if (xen_mode == XEN_DISABLED) {
         error_setg(errp, "xen-platform device requires a Xen guest");
         return;
     }

     pci_conf = dev->config;

     pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_IO | PCI_COMMAND_MEMORY);

     pci_config_set_prog_interface(pci_conf, 0);

     pci_conf[PCI_INTERRUPT_PIN] = 1;

     platform_ioport_bar_setup(d);
     pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_IO, &d->bar);

     /* reserve 16MB mmio address for share memory*/
     platform_mmio_setup(d);
     pci_register_bar(dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
                      &d->mmio_bar);

     platform_fixed_ioport_init(d);
 }

 static void platform_reset(DeviceState *dev)
 {
     PCIXenPlatformState *s = XEN_PLATFORM(dev);

     platform_fixed_ioport_reset(s);
 }

 static void xen_platform_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);

     k->realize = xen_platform_realize;
     k->vendor_id = PCI_VENDOR_ID_XEN;
     k->device_id = PCI_DEVICE_ID_XEN_PLATFORM;
     k->class_id = PCI_CLASS_OTHERS << 8 | 0x80;
     k->subsystem_vendor_id = PCI_VENDOR_ID_XEN;
     k->subsystem_id = PCI_DEVICE_ID_XEN_PLATFORM;
     k->revision = 1;
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
     dc->desc = "XEN platform pci device";
     dc->reset = platform_reset;
     dc->vmsd = &vmstate_xen_platform;
 }

 static const TypeInfo xen_platform_info = {
     .name          = TYPE_XEN_PLATFORM,
     .parent        = TYPE_PCI_DEVICE,
     .instance_size = sizeof(PCIXenPlatformState),
     .class_init    = xen_platform_class_init,
     .interfaces = (InterfaceInfo[]) {
         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
         { },
     },
 };

 static void xen_platform_register_types(void)
 {
     type_register_static(&xen_platform_info);
 }

 type_init(xen_platform_register_types)
	/*
	* XEN platform pci device, formerly known as the event channel device
	*
	* Copyright (c) 2003-2004 Intel Corp.
	* Copyright (c) 2006 XenSource
	*
	* 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 "qapi/error.h"
	#include "hw/ide/pci.h"
	#include "hw/pci/pci.h"
	#include "migration/vmstate.h"
	#include "net/net.h"
	#include "trace.h"
	#include "sysemu/xen.h"
	#include "sysemu/block-backend.h"
	#include "qemu/error-report.h"
	#include "qemu/module.h"
	#include "qom/object.h"

	#ifdef CONFIG_XEN
	#include "hw/xen/xen_native.h"
	#endif

	/* The rule is that xen_native.h must come first */
	#include "hw/xen/xen.h"

	//#define DEBUG_PLATFORM

	#ifdef DEBUG_PLATFORM
	#define DPRINTF(fmt, ...) do { \
	fprintf(stderr, "xen_platform: " fmt, ## __VA_ARGS__); \
	} while (0)
	#else
	#define DPRINTF(fmt, ...) do { } while (0)
	#endif

	#define PFFLAG_ROM_LOCK 1 /* Sets whether ROM memory area is RW or RO */

	struct PCIXenPlatformState {
	/< private >/
	PCIDevice parent_obj;
	/< public >/

	MemoryRegion fixed_io;
	MemoryRegion bar;
	MemoryRegion mmio_bar;
	uint8_t flags; /* used only for version_id == 2 */
	uint16_t driver_product_version;

	/* Log from guest drivers */
	char log_buffer[4096];
	int log_buffer_off;
	};

	#define TYPE_XEN_PLATFORM "xen-platform"
	OBJECT_DECLARE_SIMPLE_TYPE(PCIXenPlatformState, XEN_PLATFORM)

	#define XEN_PLATFORM_IOPORT 0x10

	/* Send bytes to syslog */
	static void log_writeb(PCIXenPlatformState *s, char val)
	{
	if (val == '\n' \|\| s->log_buffer_off == sizeof(s->log_buffer) - 1) {
	/* Flush buffer */
	s->log_buffer[s->log_buffer_off] = 0;
	trace_xen_platform_log(s->log_buffer);
	s->log_buffer_off = 0;
	} else {
	s->log_buffer[s->log_buffer_off++] = val;
	}
	}

	/*
	* Unplug device flags.
	*
	* The logic got a little confused at some point in the past but this is
	* what they do now.
	*
	* bit 0: Unplug all IDE and SCSI disks.
	* bit 1: Unplug all NICs.
	* bit 2: Unplug IDE disks except primary master. This is overridden if
	* bit 0 is also present in the mask.
	* bit 3: Unplug all NVMe disks.
	*
	*/
	#define _UNPLUG_IDE_SCSI_DISKS 0
	#define UNPLUG_IDE_SCSI_DISKS (1u << _UNPLUG_IDE_SCSI_DISKS)

	#define _UNPLUG_ALL_NICS 1
	#define UNPLUG_ALL_NICS (1u << _UNPLUG_ALL_NICS)

	#define _UNPLUG_AUX_IDE_DISKS 2
	#define UNPLUG_AUX_IDE_DISKS (1u << _UNPLUG_AUX_IDE_DISKS)

	#define _UNPLUG_NVME_DISKS 3
	#define UNPLUG_NVME_DISKS (1u << _UNPLUG_NVME_DISKS)

	static bool pci_device_is_passthrough(PCIDevice *d)
	{
	if (!strcmp(d->name, "xen-pci-passthrough")) {
	return true;
	}

	if (xen_mode == XEN_EMULATE && !strcmp(d->name, "vfio-pci")) {
	return true;
	}

	return false;
	}

	static void unplug_nic(PCIBus b, PCIDevice d, void *o)
	{
	/* We have to ignore passthrough devices */
	if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
	PCI_CLASS_NETWORK_ETHERNET
	&& !pci_device_is_passthrough(d)) {
	object_unparent(OBJECT(d));
	}
	}

	/* Remove the peer of the NIC device. Normally, this would be a tap device. */
	static void del_nic_peer(NICState nic, void opaque)
	{
	NetClientState *nc;

	nc = qemu_get_queue(nic);
	if (nc->peer)
	qemu_del_net_client(nc->peer);
	}

	static void pci_unplug_nics(PCIBus *bus)
	{
	qemu_foreach_nic(del_nic_peer, NULL);
	pci_for_each_device(bus, 0, unplug_nic, NULL);
	}

	/*
	* The Xen HVM unplug protocol [1] specifies a mechanism to allow guests to
	* request unplug of 'aux' disks (which is stated to mean all IDE disks,
	* except the primary master).
	*
	* NOTE: The semantics of what happens if unplug of all disks and 'aux' disks
	* is simultaneously requested is not clear. The implementation assumes
	* that an 'all' request overrides an 'aux' request.
	*
	* [1] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/hvm-emulated-unplug.pandoc
	*/
	static void pci_xen_ide_unplug(PCIDevice *d, bool aux)
	{
	DeviceState *dev = DEVICE(d);
	PCIIDEState *pci_ide;
	int i;
	IDEDevice *idedev;
	IDEBus *idebus;
	BlockBackend *blk;

	pci_ide = PCI_IDE(dev);

	for (i = aux ? 1 : 0; i < 4; i++) {
	idebus = &pci_ide->bus[i / 2];
	blk = idebus->ifs[i % 2].blk;

	if (blk && idebus->ifs[i % 2].drive_kind != IDE_CD) {
	if (!(i % 2)) {
	idedev = idebus->master;
	} else {
	idedev = idebus->slave;
	}

	blk_drain(blk);
	blk_flush(blk);

	blk_detach_dev(blk, DEVICE(idedev));
	idebus->ifs[i % 2].blk = NULL;
	idedev->conf.blk = NULL;
	monitor_remove_blk(blk);
	blk_unref(blk);
	}
	}
	pci_device_reset(d);
	}

	static void unplug_disks(PCIBus b, PCIDevice d, void *opaque)
	{
	uint32_t flags = (uint32_t )opaque;
	bool aux = (flags & UNPLUG_AUX_IDE_DISKS) &&
	!(flags & UNPLUG_IDE_SCSI_DISKS);

	/* We have to ignore passthrough devices */
	if (pci_device_is_passthrough(d))
	return;

	switch (pci_get_word(d->config + PCI_CLASS_DEVICE)) {
	case PCI_CLASS_STORAGE_IDE:
	pci_xen_ide_unplug(d, aux);
	break;

	case PCI_CLASS_STORAGE_SCSI:
	if (!aux) {
	object_unparent(OBJECT(d));
	}
	break;

	case PCI_CLASS_STORAGE_EXPRESS:
	if (flags & UNPLUG_NVME_DISKS) {
	object_unparent(OBJECT(d));
	}

	default:
	break;
	}
	}

	static void pci_unplug_disks(PCIBus *bus, uint32_t flags)
	{
	pci_for_each_device(bus, 0, unplug_disks, &flags);
	}

	static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
	{
	PCIXenPlatformState *s = opaque;

	switch (addr) {
	case 0: {
	PCIDevice *pci_dev = PCI_DEVICE(s);
	/* Unplug devices. See comment above flag definitions */
	if (val & (UNPLUG_IDE_SCSI_DISKS \| UNPLUG_AUX_IDE_DISKS \|
	UNPLUG_NVME_DISKS)) {
	DPRINTF("unplug disks\n");
	pci_unplug_disks(pci_get_bus(pci_dev), val);
	}
	if (val & UNPLUG_ALL_NICS) {
	DPRINTF("unplug nics\n");
	pci_unplug_nics(pci_get_bus(pci_dev));
	}
	break;
	}
	case 2:
	switch (val) {
	case 1:
	DPRINTF("Citrix Windows PV drivers loaded in guest\n");
	break;
	case 0:
	DPRINTF("Guest claimed to be running PV product 0?\n");
	break;
	default:
	DPRINTF("Unknown PV product %d loaded in guest\n", val);
	break;
	}
	s->driver_product_version = val;
	break;
	}
	}

	static void platform_fixed_ioport_writel(void *opaque, uint32_t addr,
	uint32_t val)
	{
	switch (addr) {
	case 0:
	/* PV driver version */
	break;
	}
	}

	static void platform_fixed_ioport_writeb(void *opaque, uint32_t addr, uint32_t val)
	{
	PCIXenPlatformState *s = opaque;

	switch (addr) {
	case 0: /* Platform flags */
	if (xen_mode == XEN_EMULATE) {
	/* XX: Use i440gx/q35 PAM setup to do this? */
	s->flags = val & PFFLAG_ROM_LOCK;
	#ifdef CONFIG_XEN
	} else {
	hvmmem_type_t mem_type = (val & PFFLAG_ROM_LOCK) ?
	HVMMEM_ram_ro : HVMMEM_ram_rw;

	if (xen_set_mem_type(xen_domid, mem_type, 0xc0, 0x40)) {
	DPRINTF("unable to change ro/rw state of ROM memory area!\n");
	} else {
	s->flags = val & PFFLAG_ROM_LOCK;
	DPRINTF("changed ro/rw state of ROM memory area. now is %s state.\n",
	(mem_type == HVMMEM_ram_ro ? "ro" : "rw"));
	}
	#endif
	}
	break;

	case 2:
	log_writeb(s, val);
	break;
	}
	}

	static uint32_t platform_fixed_ioport_readw(void *opaque, uint32_t addr)
	{
	switch (addr) {
	case 0:
	/* Magic value so that you can identify the interface. */
	return 0x49d2;
	default:
	return 0xffff;
	}
	}

	static uint32_t platform_fixed_ioport_readb(void *opaque, uint32_t addr)
	{
	PCIXenPlatformState *s = opaque;

	switch (addr) {
	case 0:
	/* Platform flags */
	return s->flags;
	case 2:
	/* Version number */
	return 1;
	default:
	return 0xff;
	}
	}

	static void platform_fixed_ioport_reset(void *opaque)
	{
	PCIXenPlatformState *s = opaque;

	platform_fixed_ioport_writeb(s, 0, 0);
	}

	static uint64_t platform_fixed_ioport_read(void *opaque,
	hwaddr addr,
	unsigned size)
	{
	switch (size) {
	case 1:
	return platform_fixed_ioport_readb(opaque, addr);
	case 2:
	return platform_fixed_ioport_readw(opaque, addr);
	default:
	return -1;
	}
	}

	static void platform_fixed_ioport_write(void *opaque, hwaddr addr,

	uint64_t val, unsigned size)
	{
	switch (size) {
	case 1:
	platform_fixed_ioport_writeb(opaque, addr, val);
	break;
	case 2:
	platform_fixed_ioport_writew(opaque, addr, val);
	break;
	case 4:
	platform_fixed_ioport_writel(opaque, addr, val);
	break;
	}
	}


	static const MemoryRegionOps platform_fixed_io_ops = {
	.read = platform_fixed_ioport_read,
	.write = platform_fixed_ioport_write,
	.valid = {
	.unaligned = true,
	},
	.impl = {
	.min_access_size = 1,
	.max_access_size = 4,
	.unaligned = true,
	},
	.endianness = DEVICE_LITTLE_ENDIAN,
	};

	static void platform_fixed_ioport_init(PCIXenPlatformState* s)
	{
	memory_region_init_io(&s->fixed_io, OBJECT(s), &platform_fixed_io_ops, s,
	"xen-fixed", 16);
	memory_region_add_subregion(get_system_io(), XEN_PLATFORM_IOPORT,
	&s->fixed_io);
	}

	/* Xen Platform PCI Device */

	static uint64_t xen_platform_ioport_readb(void *opaque, hwaddr addr,
	unsigned int size)
	{
	if (addr == 0) {
	return platform_fixed_ioport_readb(opaque, 0);
	} else {
	return ~0u;
	}
	}

	static void xen_platform_ioport_writeb(void *opaque, hwaddr addr,
	uint64_t val, unsigned int size)
	{
	PCIXenPlatformState *s = opaque;
	PCIDevice *pci_dev = PCI_DEVICE(s);

	switch (addr) {
	case 0: /* Platform flags */
	platform_fixed_ioport_writeb(opaque, 0, (uint32_t)val);
	break;
	case 4:
	if (val == 1) {
	/*
	* SUSE unplug for Xenlinux
	* xen-kmp used this since xen-3.0.4, instead the official protocol
	* from xen-3.3+ It did an unconditional "outl(1, (ioaddr + 4));"
	* Pre VMDP 1.7 used 4 and 8 depending on how VMDP was configured.
	* If VMDP was to control both disk and LAN it would use 4.
	* If it controlled just disk or just LAN, it would use 8 below.
	*/
	pci_unplug_disks(pci_get_bus(pci_dev), UNPLUG_IDE_SCSI_DISKS);
	pci_unplug_nics(pci_get_bus(pci_dev));
	}
	break;
	case 8:
	switch (val) {
	case 1:
	pci_unplug_disks(pci_get_bus(pci_dev), UNPLUG_IDE_SCSI_DISKS);
	break;
	case 2:
	pci_unplug_nics(pci_get_bus(pci_dev));
	break;
	default:
	log_writeb(s, (uint32_t)val);
	break;
	}
	break;
	default:
	break;
	}
	}

	static const MemoryRegionOps xen_pci_io_ops = {
	.read = xen_platform_ioport_readb,
	.write = xen_platform_ioport_writeb,
	.impl.min_access_size = 1,
	.impl.max_access_size = 1,
	};

	static void platform_ioport_bar_setup(PCIXenPlatformState *d)
	{
	memory_region_init_io(&d->bar, OBJECT(d), &xen_pci_io_ops, d,
	"xen-pci", 0x100);
	}

	static uint64_t platform_mmio_read(void *opaque, hwaddr addr,
	unsigned size)
	{
	DPRINTF("Warning: attempted read from physical address "
	"0x" HWADDR_FMT_plx " in xen platform mmio space\n", addr);

	return 0;
	}

	static void platform_mmio_write(void *opaque, hwaddr addr,
	uint64_t val, unsigned size)
	{
	DPRINTF("Warning: attempted write of 0x%"PRIx64" to physical "
	"address 0x" HWADDR_FMT_plx " in xen platform mmio space\n",
	val, addr);
	}

	static const MemoryRegionOps platform_mmio_handler = {
	.read = &platform_mmio_read,
	.write = &platform_mmio_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	};

	static void platform_mmio_setup(PCIXenPlatformState *d)
	{
	memory_region_init_io(&d->mmio_bar, OBJECT(d), &platform_mmio_handler, d,
	"xen-mmio", 0x1000000);
	}

	static int xen_platform_post_load(void *opaque, int version_id)
	{
	PCIXenPlatformState *s = opaque;

	platform_fixed_ioport_writeb(s, 0, s->flags);

	return 0;
	}

	static const VMStateDescription vmstate_xen_platform = {
	.name = "platform",
	.version_id = 4,
	.minimum_version_id = 4,
	.post_load = xen_platform_post_load,
	.fields = (VMStateField[]) {
	VMSTATE_PCI_DEVICE(parent_obj, PCIXenPlatformState),
	VMSTATE_UINT8(flags, PCIXenPlatformState),
	VMSTATE_END_OF_LIST()
	}
	};

	static void xen_platform_realize(PCIDevice dev, Error *errp)
	{
	PCIXenPlatformState *d = XEN_PLATFORM(dev);
	uint8_t *pci_conf;

	/* Device will crash on reset if xen is not initialized */
	if (xen_mode == XEN_DISABLED) {
	error_setg(errp, "xen-platform device requires a Xen guest");
	return;
	}

	pci_conf = dev->config;

	pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_IO \| PCI_COMMAND_MEMORY);

	pci_config_set_prog_interface(pci_conf, 0);

	pci_conf[PCI_INTERRUPT_PIN] = 1;

	platform_ioport_bar_setup(d);
	pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_IO, &d->bar);

	/* reserve 16MB mmio address for share memory*/
	platform_mmio_setup(d);
	pci_register_bar(dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
	&d->mmio_bar);

	platform_fixed_ioport_init(d);
	}

	static void platform_reset(DeviceState *dev)
	{
	PCIXenPlatformState *s = XEN_PLATFORM(dev);

	platform_fixed_ioport_reset(s);
	}

	static void xen_platform_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);

	k->realize = xen_platform_realize;
	k->vendor_id = PCI_VENDOR_ID_XEN;
	k->device_id = PCI_DEVICE_ID_XEN_PLATFORM;
	k->class_id = PCI_CLASS_OTHERS << 8 \| 0x80;
	k->subsystem_vendor_id = PCI_VENDOR_ID_XEN;
	k->subsystem_id = PCI_DEVICE_ID_XEN_PLATFORM;
	k->revision = 1;
	set_bit(DEVICE_CATEGORY_MISC, dc->categories);
	dc->desc = "XEN platform pci device";
	dc->reset = platform_reset;
	dc->vmsd = &vmstate_xen_platform;
	}

	static const TypeInfo xen_platform_info = {
	.name = TYPE_XEN_PLATFORM,
	.parent = TYPE_PCI_DEVICE,
	.instance_size = sizeof(PCIXenPlatformState),
	.class_init = xen_platform_class_init,
	.interfaces = (InterfaceInfo[]) {
	{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
	{ },
	},
	};

	static void xen_platform_register_types(void)
	{
	type_register_static(&xen_platform_info);
	}

	type_init(xen_platform_register_types)