Re: [Qemu-devel] [PATCH 1/2] i386: Add a Virtual Machine Generation ID device

[Gal Hammer <ghammer@redhat.com>]

On 19/10/2014 18:14, Michael S. Tsirkin wrote:
> On Sun, Oct 19, 2014 at 04:43:07PM +0300, Gal Hammer wrote:
>> Based on Microsoft's sepecifications (paper can be dowloaded from
>> http://go.microsoft.com/fwlink/?LinkId=260709), add a device
>> description to the SSDT ACPI table and its implementation.
>>
>> The GUID is set using a global "vmgenid.uuid" parameter.
>>
>> Signed-off-by: Gal Hammer <ghammer@redhat.com>
>>
>> ---
>>   default-configs/i386-softmmu.mak     |   1 +
>>   default-configs/x86_64-softmmu.mak   |   1 +
>>   hw/acpi/core.c                       |   8 +++
>>   hw/acpi/ich9.c                       |   8 +++
>>   hw/acpi/piix4.c                      |   8 +++
>>   hw/i386/acpi-build.c                 |   8 +++
>>   hw/i386/acpi-dsdt.dsl                |   4 +-
>>   hw/i386/acpi-dsdt.hex.generated      |   6 +-
>>   hw/i386/pc.c                         |   8 +++
>>   hw/i386/q35-acpi-dsdt.dsl            |   5 +-
>>   hw/i386/q35-acpi-dsdt.hex.generated  |   8 +--
>>   hw/i386/ssdt-misc.dsl                |  36 +++++++++++
>>   hw/i386/ssdt-misc.hex.generated      |   8 +--
>>   hw/isa/lpc_ich9.c                    |   1 +
>>   hw/misc/Makefile.objs                |   1 +
>>   hw/misc/vmgenid.c                    | 116 +++++++++++++++++++++++++++++++++++
>>   include/hw/acpi/acpi.h               |   2 +
>>   include/hw/acpi/acpi_dev_interface.h |   4 ++
>>   include/hw/acpi/ich9.h               |   2 +
>>   include/hw/i386/pc.h                 |   3 +
>>   include/hw/misc/vmgenid.h            |  21 +++++++
>>   21 files changed, 246 insertions(+), 13 deletions(-)
>>   create mode 100644 hw/misc/vmgenid.c
>>   create mode 100644 include/hw/misc/vmgenid.h
>
> Please document the host/guest API.
> It seems that you are using a hard-coded hardware address,
> and using up a GPE.

I'll add a document file which describes the device's implementation.

>
>
>>
>> diff --git a/default-configs/i386-softmmu.mak b/default-configs/i386-softmmu.mak
>> index 8e08841..bd33c75 100644
>> --- a/default-configs/i386-softmmu.mak
>> +++ b/default-configs/i386-softmmu.mak
>> @@ -45,3 +45,4 @@ CONFIG_IOAPIC=y
>>   CONFIG_ICC_BUS=y
>>   CONFIG_PVPANIC=y
>>   CONFIG_MEM_HOTPLUG=y
>> +CONFIG_VMGENID=y
>> diff --git a/default-configs/x86_64-softmmu.mak b/default-configs/x86_64-softmmu.mak
>> index 66557ac..006fc7c 100644
>> --- a/default-configs/x86_64-softmmu.mak
>> +++ b/default-configs/x86_64-softmmu.mak
>> @@ -45,3 +45,4 @@ CONFIG_IOAPIC=y
>>   CONFIG_ICC_BUS=y
>>   CONFIG_PVPANIC=y
>>   CONFIG_MEM_HOTPLUG=y
>> +CONFIG_VMGENID=y
>> diff --git a/hw/acpi/core.c b/hw/acpi/core.c
>> index a7368fb..a01c980 100644
>> --- a/hw/acpi/core.c
>> +++ b/hw/acpi/core.c
>> @@ -28,6 +28,8 @@
>>   #include "qapi-visit.h"
>>   #include "qapi-event.h"
>>
>> +#define ACPI_VM_GENERATION_ID_CHANGED_STATUS 1
>> +
>>   struct acpi_table_header {
>>       uint16_t _length;         /* our length, not actual part of the hdr */
>>                                 /* allows easier parsing for fw_cfg clients */
>> @@ -680,3 +682,9 @@ void acpi_update_sci(ACPIREGS *regs, qemu_irq irq)
>>                          (regs->pm1.evt.en & ACPI_BITMASK_TIMER_ENABLE) &&
>>                          !(pm1a_sts & ACPI_BITMASK_TIMER_STATUS));
>>   }
>> +
>> +void acpi_vm_generation_id_changed(ACPIREGS *acpi_regs, qemu_irq irq)
>> +{
>> +    acpi_regs->gpe.sts[0] |= ACPI_VM_GENERATION_ID_CHANGED_STATUS;
>> +    acpi_update_sci(acpi_regs, irq);
>> +}
>> diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
>> index 7b14bbb..5501c0e 100644
>> --- a/hw/acpi/ich9.c
>> +++ b/hw/acpi/ich9.c
>> @@ -316,3 +316,11 @@ void ich9_pm_ospm_status(AcpiDeviceIf *adev, ACPIOSTInfoList ***list)
>>
>>       acpi_memory_ospm_status(&s->pm.acpi_memory_hotplug, list);
>>   }
>> +
>> +void ich9_vm_generation_id_changed(AcpiDeviceIf *adev)
>> +{
>> +    ICH9LPCState *s = ICH9_LPC_DEVICE(adev);
>> +    ICH9LPCPMRegs *pm = &s->pm;
>> +
>> +    acpi_vm_generation_id_changed(&pm->acpi_regs, pm->irq);
>> +}
>> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
>> index 0bfa814..ad0ef68 100644
>> --- a/hw/acpi/piix4.c
>> +++ b/hw/acpi/piix4.c
>> @@ -580,6 +580,13 @@ static void piix4_ospm_status(AcpiDeviceIf *adev, ACPIOSTInfoList ***list)
>>       acpi_memory_ospm_status(&s->acpi_memory_hotplug, list);
>>   }
>>
>> +static void piix4_vm_generation_id_changed(AcpiDeviceIf *adev)
>> +{
>> +    PIIX4PMState *s = PIIX4_PM(adev);
>> +
>> +    acpi_vm_generation_id_changed(&s->ar, s->irq);
>> +}
>> +
>>   static Property piix4_pm_properties[] = {
>>       DEFINE_PROP_UINT32("smb_io_base", PIIX4PMState, smb_io_base, 0),
>>       DEFINE_PROP_UINT8(ACPI_PM_PROP_S3_DISABLED, PIIX4PMState, disable_s3, 0),
>> @@ -617,6 +624,7 @@ static void piix4_pm_class_init(ObjectClass *klass, void *data)
>>       hc->plug = piix4_device_plug_cb;
>>       hc->unplug_request = piix4_device_unplug_request_cb;
>>       adevc->ospm_status = piix4_ospm_status;
>> +    adevc->vm_generation_id_changed = piix4_vm_generation_id_changed;
>>   }
>>
>>   static const TypeInfo piix4_pm_info = {
>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>> index 00be4bb..27d0494 100644
>> --- a/hw/i386/acpi-build.c
>> +++ b/hw/i386/acpi-build.c
>> @@ -42,6 +42,7 @@
>>   #include "hw/acpi/memory_hotplug.h"
>>   #include "sysemu/tpm.h"
>>   #include "hw/acpi/tpm.h"
>> +#include "hw/misc/vmgenid.h"
>>
>>   /* Supported chipsets: */
>>   #include "hw/acpi/piix4.h"
>> @@ -96,6 +97,7 @@ typedef struct AcpiMiscInfo {
>>       const unsigned char *dsdt_code;
>>       unsigned dsdt_size;
>>       uint16_t pvpanic_port;
>> +    bool vm_generation_id_set;
>>   } AcpiMiscInfo;
>>
>>   typedef struct AcpiBuildPciBusHotplugState {
>> @@ -216,6 +218,7 @@ static void acpi_get_misc_info(AcpiMiscInfo *info)
>>       info->has_hpet = hpet_find();
>>       info->has_tpm = tpm_find();
>>       info->pvpanic_port = pvpanic_port();
>> +    info->vm_generation_id_set = vm_generation_id_set();
>>   }
>>
>>   static void acpi_get_pci_info(PcPciInfo *info)
>> @@ -1088,6 +1091,11 @@ build_ssdt(GArray *table_data, GArray *linker,
>>       ACPI_BUILD_SET_LE(ssdt_ptr, sizeof(ssdp_misc_aml),
>>                         ssdt_isa_pest[0], 16, misc->pvpanic_port);
>>
>> +    if (!misc->vm_generation_id_set) {
>> +        ACPI_BUILD_SET_LE(ssdt_ptr, sizeof(ssdp_misc_aml),
>> +                          ssdt_acpi_vm_gid_addr[0], 32, 0);
>> +    }
>> +
>>       ACPI_BUILD_SET_LE(ssdt_ptr, sizeof(ssdp_misc_aml),
>>                         ssdt_mctrl_nr_slots[0], 32, nr_mem);
>>
>> diff --git a/hw/i386/acpi-dsdt.dsl b/hw/i386/acpi-dsdt.dsl
>> index 559f4b6..10b4afb 100644
>> --- a/hw/i386/acpi-dsdt.dsl
>> +++ b/hw/i386/acpi-dsdt.dsl
>> @@ -307,7 +307,9 @@ DefinitionBlock (
>>       Scope(\_GPE) {
>>           Name(_HID, "ACPI0006")
>>
>> -        Method(_L00) {
>> +        External(\_SB.VMGI, DeviceObj)
>> +        Method(_E00) {
>> +            Notify(\_SB.VMGI, 0x80)
>>           }
>>           Method(_E01) {
>>               // PCI hotplug event
>> diff --git a/hw/i386/acpi-dsdt.hex.generated b/hw/i386/acpi-dsdt.hex.generated
>> index a21bf41..3fd06d2 100644
>> --- a/hw/i386/acpi-dsdt.hex.generated
>> +++ b/hw/i386/acpi-dsdt.hex.generated
>> @@ -8,7 +8,7 @@ static unsigned char AcpiDsdtAmlCode[] = {
>>   0x0,
>>   0x0,
>>   0x1,
>> -0x1f,
>> +0x18,
>>   0x42,
>>   0x58,
>>   0x50,
>> @@ -32,8 +32,8 @@ static unsigned char AcpiDsdtAmlCode[] = {
>>   0x54,
>>   0x4c,
>>   0x28,
>> -0x5,
>> -0x10,
>> +0x8,
>> +0x14,
>>   0x20,
>>   0x10,
>>   0x49,
>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>> index d045e8b..95ec233 100644
>> --- a/hw/i386/pc.c
>> +++ b/hw/i386/pc.c
>> @@ -59,6 +59,7 @@
>>   #include "hw/pci/pci_host.h"
>>   #include "acpi-build.h"
>>   #include "hw/mem/pc-dimm.h"
>> +#include "hw/misc/vmgenid.h"
>>   #include "trace.h"
>>   #include "qapi/visitor.h"
>>
>> @@ -1361,6 +1362,7 @@ void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
>>       int i;
>>       DriveInfo *fd[MAX_FD];
>>       DeviceState *hpet = NULL;
>> +    DeviceState *vmgenid;
>>       int pit_isa_irq = 0;
>>       qemu_irq pit_alt_irq = NULL;
>>       qemu_irq rtc_irq = NULL;
>> @@ -1459,6 +1461,12 @@ void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
>>           fd[i] = drive_get(IF_FLOPPY, 0, i);
>>       }
>>       *floppy = fdctrl_init_isa(isa_bus, fd);
>> +
>> +    vmgenid = qdev_try_create(NULL, VMGENID_DEVICE);
>> +    if (vmgenid) {
>> +        qdev_init_nofail(vmgenid);
>> +        sysbus_mmio_map(SYS_BUS_DEVICE(vmgenid), 0, VMGENID_BASE_ADDRESS);
>> +    }
>>   }
>>
>>   void pc_nic_init(ISABus *isa_bus, PCIBus *pci_bus)
>> diff --git a/hw/i386/q35-acpi-dsdt.dsl b/hw/i386/q35-acpi-dsdt.dsl
>> index 054b035..b1d04e2 100644
>> --- a/hw/i386/q35-acpi-dsdt.dsl
>> +++ b/hw/i386/q35-acpi-dsdt.dsl
>> @@ -415,7 +415,10 @@ DefinitionBlock (
>>       Scope(\_GPE) {
>>           Name(_HID, "ACPI0006")
>>
>> -        Method(_L00) {
>> +        External(\_SB.VMGI, DeviceObj)
>> +        Method(_E00)
>> +        {
>> +            Notify(\_SB.VMGI, 0x80)
>>           }
>>           Method(_L01) {
>>           }
>> diff --git a/hw/i386/q35-acpi-dsdt.hex.generated b/hw/i386/q35-acpi-dsdt.hex.generated
>> index c9eb4ac..866e648 100644
>> --- a/hw/i386/q35-acpi-dsdt.hex.generated
>> +++ b/hw/i386/q35-acpi-dsdt.hex.generated
>> @@ -8,7 +8,7 @@ static unsigned char Q35AcpiDsdtAmlCode[] = {
>>   0x0,
>>   0x0,
>>   0x1,
>> -0xb7,
>> +0xac,
>>   0x42,
>>   0x58,
>>   0x50,
>> @@ -31,9 +31,9 @@ static unsigned char Q35AcpiDsdtAmlCode[] = {
>>   0x4e,
>>   0x54,
>>   0x4c,
>> -0x15,
>> -0x11,
>> -0x13,
>> +0x28,
>> +0x8,
>> +0x14,
>>   0x20,
>>   0x10,
>>   0x49,
>> diff --git a/hw/i386/ssdt-misc.dsl b/hw/i386/ssdt-misc.dsl
>> index 0fd4480..6ae09fb 100644
>> --- a/hw/i386/ssdt-misc.dsl
>> +++ b/hw/i386/ssdt-misc.dsl
>> @@ -13,6 +13,7 @@
>>    * with this program; if not, see <http://www.gnu.org/licenses/>.
>>    */
>>   #include "hw/acpi/pc-hotplug.h"
>> +#include "hw/misc/vmgenid.h"
>>
>>   ACPI_EXTRACT_ALL_CODE ssdp_misc_aml
>>
>> @@ -118,6 +119,41 @@ DefinitionBlock ("ssdt-misc.aml", "SSDT", 0x01, "BXPC", "BXSSDTSUSP", 0x1)
>>           }
>>       }
>>
>> +    Scope(\_SB) {
>> +        Device(VMGI) {
>> +            Name(_HID, "QEMU0002")
>> +            Name(_CID, "VM_Gen_Counter")
>> +            Name(_DDN, "VM_Gen_Counter")
>> +
>> +            ACPI_EXTRACT_NAME_DWORD_CONST ssdt_acpi_vm_gid_addr
>> +            Name(VGIA, VMGENID_BASE_ADDRESS)
>> +
>> +            OperationRegion(VGID, SystemMemory,
>> +                VMGENID_BASE_ADDRESS, VMGENID_BASE_ADDR_LEN)
>> +
>> +            Name(_CRS, ResourceTemplate() {
>> +                Memory32Fixed(ReadOnly,
>> +                    VMGENID_BASE_ADDRESS, VMGENID_BASE_ADDR_LEN)
>> +            })
>> +
>> +            Method(_STA, 0, NotSerialized) {
>> +                Store(VGIA, Local0)
>> +                If (LEqual(Local0, Zero)) {
>> +                    Return (0x00)
>> +                } Else {
>> +                    Return (0x0F)
>> +                }
>> +            }
>> +
>> +            Method(ADDR, 0, Serialized) {
>> +                Store(Package(2) { }, Local0)
>> +                Store(VGIA, Index(Local0, 0))
>> +                Store(0x0000, Index(Local0, 1))
>> +                return (Local0)
>> +            }
>> +        }
>> +    }
>> +
>>       External(MEMORY_SLOT_NOTIFY_METHOD, MethodObj)
>>       Scope(\_SB.PCI0) {
>>           Device(MEMORY_HOTPLUG_DEVICE) {
>> diff --git a/hw/i386/ssdt-misc.hex.generated b/hw/i386/ssdt-misc.hex.generated
>> index ba4268a..f0b7a27 100644
>> --- a/hw/i386/ssdt-misc.hex.generated
>> +++ b/hw/i386/ssdt-misc.hex.generated
>> @@ -26,7 +26,7 @@ static unsigned char ssdp_misc_aml[] = {
>>   0x0,
>>   0x0,
>>   0x1,
>> -0x8b,
>> +0x80,
>>   0x42,
>>   0x58,
>>   0x50,
>> @@ -49,9 +49,9 @@ static unsigned char ssdp_misc_aml[] = {
>>   0x4e,
>>   0x54,
>>   0x4c,
>> -0x15,
>> -0x11,
>> -0x13,
>> +0x28,
>> +0x8,
>> +0x14,
>>   0x20,
>>   0x10,
>>   0x42,
>> diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
>> index 530b074..3a012fa 100644
>> --- a/hw/isa/lpc_ich9.c
>> +++ b/hw/isa/lpc_ich9.c
>> @@ -678,6 +678,7 @@ static void ich9_lpc_class_init(ObjectClass *klass, void *data)
>>       hc->plug = ich9_device_plug_cb;
>>       hc->unplug_request = ich9_device_unplug_request_cb;
>>       adevc->ospm_status = ich9_pm_ospm_status;
>> +    adevc->vm_generation_id_changed = ich9_vm_generation_id_changed;
>>   }
>>
>>   static const TypeInfo ich9_lpc_info = {
>> diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
>> index 979e532..c18b800 100644
>> --- a/hw/misc/Makefile.objs
>> +++ b/hw/misc/Makefile.objs
>> @@ -41,3 +41,4 @@ obj-$(CONFIG_SLAVIO) += slavio_misc.o
>>   obj-$(CONFIG_ZYNQ) += zynq_slcr.o
>>
>>   obj-$(CONFIG_PVPANIC) += pvpanic.o
>> +obj-$(CONFIG_VMGENID) += vmgenid.o
>> diff --git a/hw/misc/vmgenid.c b/hw/misc/vmgenid.c
>> new file mode 100644
>> index 0000000..01aacd4
>> --- /dev/null
>> +++ b/hw/misc/vmgenid.c
>> @@ -0,0 +1,116 @@
>> +/*
>> + *  Virtual Machine Generation ID Device
>> + *
>> + *  Copyright (C) 2014 Red Hat Inc.
>> + *
>> + *  Authors: Gal Hammer <ghammer@redhat.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
>> + * See the COPYING file in the top-level directory.
>> + *
>> + */
>> +
>> +#include "hw/i386/pc.h"
>> +#include "hw/sysbus.h"
>> +#include "hw/misc/vmgenid.h"
>> +#include "hw/acpi/acpi_dev_interface.h"
>> +
>> +#define PROPERTY_UUID "uuid"
>> +
>> +#define VMGENID(obj) OBJECT_CHECK(VmGenIdState, (obj), VMGENID_DEVICE)
>> +
>> +typedef struct VmGenIdState {
>> +    SysBusDevice parent_obj;
>> +    MemoryRegion iomem;
>> +    uint8_t guid[16];
>> +    bool guid_set;
>> +} VmGenIdState;
>> +
>> +bool vm_generation_id_set(void)
>> +{
>> +    Object *obj = object_resolve_path_type("", VMGENID_DEVICE, NULL);
>> +    VmGenIdState *s = VMGENID(obj);
>> +
>> +    if (!obj) {
>> +        return false;
>> +    }
>> +    return s->guid_set;
>> +}
>> +
>> +static uint64_t vmgenid_ram_read(void *opaque, hwaddr addr,
>> +                                 unsigned size)
>> +{
>> +    VmGenIdState *s = VMGENID(opaque);
>> +    uint64_t value;
>> +
>> +    memcpy(&value, s->guid + addr, size);
>> +    return value;
>> +}
>> +
>> +static const MemoryRegionOps vmgenid_ram_ops = {
>> +    .read = vmgenid_ram_read,
>> +    .valid = {
>> +        .min_access_size = 4,
>> +        .max_access_size = 4,
>> +    },
>> +    .endianness = DEVICE_NATIVE_ENDIAN,
>> +};
>> +
>> +static void vmgenid_set_uuid(Object *obj, const char *value, Error **errp)
>> +{
>> +    VmGenIdState *s = VMGENID(obj);
>> +    Object *acpi_obj;
>> +    bool first_set = !s->guid_set;
>> +
>> +    if (qemu_uuid_parse(value, s->guid) < 0) {
>> +        error_setg(errp, "Fail to parse UUID string.");
>> +        return;
>> +    }
>> +    s->guid_set = true;
>> +
>> +    /* Skip the acpi notification when setting the vm generation id for the
>> +     * first time. This is done because in a q35 machine the gpe register is
>> +     * allocated after the device is initialized. */
>> +    if (!first_set) {
>> +        acpi_obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, NULL);
>> +        if (acpi_obj) {
>> +            AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(acpi_obj);
>> +            AcpiDeviceIf *adev = ACPI_DEVICE_IF(acpi_obj);
>> +
>> +            adevc->vm_generation_id_changed(adev);
>> +        }
>> +    }
>> +}
>> +
>> +static void vmgenid_init(Object *obj)
>> +{
>> +    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
>> +    VmGenIdState *s = VMGENID(obj);
>> +
>> +    memory_region_init_io(&s->iomem, obj, &vmgenid_ram_ops, s, "vgid", 16);
>> +    sysbus_init_mmio(sbd, &s->iomem);
>
> This will cause an exit on each access to the GID.
> I'm guessing this is too expensive.

Yes, it does cause an exit, but I don't think it is critical because the 
GID is rarely read by the guest OS. As far as I can tell it is only 
accessed on reboot and when the GID is changed.

Do you prefer that I'll use the cpu_physical_memory_write function? Or 
do you have a diffrent idea on how to implement it?

>
>
>> +
>> +    object_property_add_str(obj, PROPERTY_UUID, NULL, vmgenid_set_uuid, NULL);
>> +}
>> +
>> +static void vmgenid_class_init(ObjectClass *klass, void *data)
>> +{
>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>> +
>> +    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
>> +}
>> +
>> +static const TypeInfo vmgenid_device_info = {
>> +    .name          = VMGENID_DEVICE,
>> +    .parent        = TYPE_SYS_BUS_DEVICE,
>> +    .instance_size = sizeof(VmGenIdState),
>> +    .instance_init = vmgenid_init,
>> +    .class_init    = vmgenid_class_init,
>> +};
>> +
>> +static void vmgenid_register_types(void)
>> +{
>> +    type_register_static(&vmgenid_device_info);
>> +}
>> +
>> +type_init(vmgenid_register_types)
>> diff --git a/include/hw/acpi/acpi.h b/include/hw/acpi/acpi.h
>> index 1f678b4..9373b4d 100644
>> --- a/include/hw/acpi/acpi.h
>> +++ b/include/hw/acpi/acpi.h
>> @@ -185,4 +185,6 @@ unsigned acpi_table_len(void *current);
>>   void acpi_table_add(const QemuOpts *opts, Error **errp);
>>   void acpi_table_add_builtin(const QemuOpts *opts, Error **errp);
>>
>> +void acpi_vm_generation_id_changed(ACPIREGS *acpi_regs, qemu_irq irq);
>> +
>>   #endif /* !QEMU_HW_ACPI_H */
>> diff --git a/include/hw/acpi/acpi_dev_interface.h b/include/hw/acpi/acpi_dev_interface.h
>> index f245f8d..757ce60 100644
>> --- a/include/hw/acpi/acpi_dev_interface.h
>> +++ b/include/hw/acpi/acpi_dev_interface.h
>> @@ -28,6 +28,9 @@ typedef struct AcpiDeviceIf {
>>    * ospm_status: returns status of ACPI device objects, reported
>>    *              via _OST method if device supports it.
>>    *
>> + * vm_generation_id_changed: notify the guest that it generation
>> + *                           id was changed.
>> + *
>>    * Interface is designed for providing unified interface
>>    * to generic ACPI functionality that could be used without
>>    * knowledge about internals of actual device that implements
>> @@ -39,5 +42,6 @@ typedef struct AcpiDeviceIfClass {
>>
>>       /* <public> */
>>       void (*ospm_status)(AcpiDeviceIf *adev, ACPIOSTInfoList ***list);
>> +    void (*vm_generation_id_changed)(AcpiDeviceIf *adev);
>>   } AcpiDeviceIfClass;
>>   #endif
>> diff --git a/include/hw/acpi/ich9.h b/include/hw/acpi/ich9.h
>> index 7e42448..3b4eed5 100644
>> --- a/include/hw/acpi/ich9.h
>> +++ b/include/hw/acpi/ich9.h
>> @@ -62,4 +62,6 @@ void ich9_pm_add_properties(Object *obj, ICH9LPCPMRegs *pm, Error **errp);
>>   void ich9_pm_device_plug_cb(ICH9LPCPMRegs *pm, DeviceState *dev, Error **errp);
>>
>>   void ich9_pm_ospm_status(AcpiDeviceIf *adev, ACPIOSTInfoList ***list);
>> +
>> +void ich9_vm_generation_id_changed(AcpiDeviceIf *adev);
>>   #endif /* HW_ACPI_ICH9_H */
>> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
>> index 1c2602e..87912b2 100644
>> --- a/include/hw/i386/pc.h
>> +++ b/include/hw/i386/pc.h
>> @@ -290,6 +290,9 @@ void pc_system_firmware_init(MemoryRegion *rom_memory,
>>   /* pvpanic.c */
>>   uint16_t pvpanic_port(void);
>>
>> +/* vmgenid.c */
>> +bool vm_generation_id_set(void);
>> +
>>   /* e820 types */
>>   #define E820_RAM        1
>>   #define E820_RESERVED   2
>> diff --git a/include/hw/misc/vmgenid.h b/include/hw/misc/vmgenid.h
>> new file mode 100644
>> index 0000000..3d44421
>> --- /dev/null
>> +++ b/include/hw/misc/vmgenid.h
>> @@ -0,0 +1,21 @@
>> +/*
>> + *  Virtual Machine Generation ID Device
>> + *
>> + *  Copyright (C) 2014 Red Hat Inc.
>> + *
>> + *  Authors: Gal Hammer <ghammer@redhat.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
>> + * See the COPYING file in the top-level directory.
>> + *
>> + */
>> +
>> +#ifndef HW_MISC_VMGENID_H
>> +#define HW_MISC_VMGENID_H
>> +
>> +#define VMGENID_DEVICE "vmgenid"
>> +
>> +#define VMGENID_BASE_ADDRESS    0xfedf0000
>> +#define VMGENID_BASE_ADDR_LEN   16
>> +
>> +#endif
>> --
>> 1.9.3