diff mbox

[3/4] xen:hw:pci-host:piix: introduce xen_igd_i440fx_init

Message ID 1406201429-21700-4-git-send-email-tiejun.chen@intel.com
State New
Headers show

Commit Message

Tiejun Chen July 24, 2014, 11:30 a.m. UTC 
This is almost same as an original i440fx_init but just
work with that xen igd host bridge to passthrough.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
 hw/pci-host/piix.c   | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/i386/pc.h | 10 +++++++
 2 files changed, 89 insertions(+)

Comments

Michael S. Tsirkin July 29, 2014, 11:19 a.m. UTC | #1 
On Thu, Jul 24, 2014 at 07:30:28PM +0800, Tiejun Chen wrote:
> This is almost same as an original i440fx_init but just
> work with that xen igd host bridge to passthrough.
> 
> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
> ---
>  hw/pci-host/piix.c   | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/i386/pc.h | 10 +++++++
>  2 files changed, 89 insertions(+)
> 
> diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
> index 9feddf5..7ef08d7 100644
> --- a/hw/pci-host/piix.c
> +++ b/hw/pci-host/piix.c
> @@ -407,6 +407,85 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
>      return b;
>  }
>  
> +PCIBus *xen_igd_i440fx_init(PCII440FXState **pi440fx_state,
> +                    int *piix3_devfn,
> +                    ISABus **isa_bus, qemu_irq *pic,
> +                    MemoryRegion *address_space_mem,
> +                    MemoryRegion *address_space_io,
> +                    ram_addr_t ram_size,
> +                    ram_addr_t below_4g_mem_size,
> +                    ram_addr_t above_4g_mem_size,
> +                    MemoryRegion *pci_address_space,
> +                    MemoryRegion *ram_memory)
> +{
> +    DeviceState *dev;
> +    PCIBus *b;
> +    PCIDevice *d;
> +    PCIHostState *s;
> +    PIIX3State *piix3;
> +    PCII440FXState *f;
> +    unsigned i;
> +    I440FXState *i440fx;
> +
> +    dev = qdev_create(NULL, TYPE_I440FX_PCI_HOST_BRIDGE);
> +    s = PCI_HOST_BRIDGE(dev);
> +    b = pci_bus_new(dev, NULL, pci_address_space,
> +                    address_space_io, 0, TYPE_PCI_BUS);
> +    s->bus = b;
> +    object_property_add_child(qdev_get_machine(), "i440fx", OBJECT(dev), NULL);
> +    qdev_init_nofail(dev);
> +
> +    d = pci_create_simple(b, 0, TYPE_I440FX_XEN_PCI_DEVICE);
> +    *pi440fx_state = I440FX_XEN_PCI_DEVICE(d);
> +    f = *pi440fx_state;
> +    f->system_memory = address_space_mem;
> +    f->pci_address_space = pci_address_space;
> +    f->ram_memory = ram_memory;
> +
> +    i440fx = I440FX_PCI_HOST_BRIDGE(dev);
> +    i440fx->pci_info.w32.begin = below_4g_mem_size;
> +
> +    /* setup pci memory mapping */
> +    pc_pci_as_mapping_init(OBJECT(f), f->system_memory,
> +                           f->pci_address_space);
> +
> +    memory_region_init_alias(&f->smram_region, OBJECT(d), "smram-region",
> +                             f->pci_address_space, 0xa0000, 0x20000);
> +    memory_region_add_subregion_overlap(f->system_memory, 0xa0000,
> +                                        &f->smram_region, 1);
> +    memory_region_set_enabled(&f->smram_region, false);
> +    init_pam(dev, f->ram_memory, f->system_memory, f->pci_address_space,
> +             &f->pam_regions[0], PAM_BIOS_BASE, PAM_BIOS_SIZE);
> +    for (i = 0; i < 12; ++i) {
> +        init_pam(dev, f->ram_memory, f->system_memory, f->pci_address_space,
> +                 &f->pam_regions[i+1], PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE,
> +                 PAM_EXPAN_SIZE);
> +    }
> +
> +    /* 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. */
> +    piix3 = DO_UPCAST(PIIX3State, dev,
> +            pci_create_simple_multifunction(b, -1, true, "PIIX3-xen"));
> +    pci_bus_irqs(b, xen_piix3_set_irq, xen_pci_slot_get_pirq,
> +            piix3, XEN_PIIX_NUM_PIRQS);
> +    piix3->pic = pic;
> +    *isa_bus = ISA_BUS(qdev_get_child_bus(DEVICE(piix3), "isa.0"));
> +
> +    *piix3_devfn = piix3->dev.devfn;
> +
> +    ram_size = ram_size / 8 / 1024 / 1024;
> +    if (ram_size > 255) {
> +        ram_size = 255;
> +    }
> +    d->config[0x57] = ram_size;
> +
> +    i440fx_update_memory_mappings(f);
> +
> +    return b;
> +}

Too much copy-paste. Please refactor to avoid code duplication.
Is the only difference here the use of TYPE_I440FX_XEN_PCI_DEVICE?
Then you can pass type in as a parameter to a common static sub-function.

> +
>  PCIBus *find_i440fx(void)
>  {
>      PCIHostState *s = OBJECT_CHECK(PCIHostState,
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 1c0c382..51656d9 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -239,6 +239,16 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
>                      MemoryRegion *pci_memory,
>                      MemoryRegion *ram_memory);
>  
> +PCIBus *xen_igd_i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
> +                    ISABus **isa_bus, qemu_irq *pic,
> +                    MemoryRegion *address_space_mem,
> +                    MemoryRegion *address_space_io,
> +                    ram_addr_t ram_size,
> +                    ram_addr_t below_4g_mem_size,
> +                    ram_addr_t above_4g_mem_size,
> +                    MemoryRegion *pci_memory,
> +                    MemoryRegion *ram_memory);
> +
>  PCIBus *find_i440fx(void);
>  /* piix4.c */
>  extern PCIDevice *piix4_dev;
> -- 
> 1.9.1
Tiejun Chen July 30, 2014, 8:24 a.m. UTC | #2 
On 2014/7/29 19:19, Michael S. Tsirkin wrote:
> On Thu, Jul 24, 2014 at 07:30:28PM +0800, Tiejun Chen wrote:
>> This is almost same as an original i440fx_init but just
>> work with that xen igd host bridge to passthrough.
>>
>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>> ---
>>   hw/pci-host/piix.c   | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   include/hw/i386/pc.h | 10 +++++++
>>   2 files changed, 89 insertions(+)
>>
>> diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
>> index 9feddf5..7ef08d7 100644
>> --- a/hw/pci-host/piix.c
>> +++ b/hw/pci-host/piix.c
>> @@ -407,6 +407,85 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
>>       return b;
>>   }
>>
>> +PCIBus *xen_igd_i440fx_init(PCII440FXState **pi440fx_state,
>> +                    int *piix3_devfn,
>> +                    ISABus **isa_bus, qemu_irq *pic,
>> +                    MemoryRegion *address_space_mem,
>> +                    MemoryRegion *address_space_io,
>> +                    ram_addr_t ram_size,
>> +                    ram_addr_t below_4g_mem_size,
>> +                    ram_addr_t above_4g_mem_size,
>> +                    MemoryRegion *pci_address_space,
>> +                    MemoryRegion *ram_memory)
>> +{
>> +    DeviceState *dev;
>> +    PCIBus *b;
>> +    PCIDevice *d;
>> +    PCIHostState *s;
>> +    PIIX3State *piix3;
>> +    PCII440FXState *f;
>> +    unsigned i;
>> +    I440FXState *i440fx;
>> +
>> +    dev = qdev_create(NULL, TYPE_I440FX_PCI_HOST_BRIDGE);
>> +    s = PCI_HOST_BRIDGE(dev);
>> +    b = pci_bus_new(dev, NULL, pci_address_space,
>> +                    address_space_io, 0, TYPE_PCI_BUS);
>> +    s->bus = b;
>> +    object_property_add_child(qdev_get_machine(), "i440fx", OBJECT(dev), NULL);
>> +    qdev_init_nofail(dev);
>> +
>> +    d = pci_create_simple(b, 0, TYPE_I440FX_XEN_PCI_DEVICE);
>> +    *pi440fx_state = I440FX_XEN_PCI_DEVICE(d);
>> +    f = *pi440fx_state;
>> +    f->system_memory = address_space_mem;
>> +    f->pci_address_space = pci_address_space;
>> +    f->ram_memory = ram_memory;
>> +
>> +    i440fx = I440FX_PCI_HOST_BRIDGE(dev);
>> +    i440fx->pci_info.w32.begin = below_4g_mem_size;
>> +
>> +    /* setup pci memory mapping */
>> +    pc_pci_as_mapping_init(OBJECT(f), f->system_memory,
>> +                           f->pci_address_space);
>> +
>> +    memory_region_init_alias(&f->smram_region, OBJECT(d), "smram-region",
>> +                             f->pci_address_space, 0xa0000, 0x20000);
>> +    memory_region_add_subregion_overlap(f->system_memory, 0xa0000,
>> +                                        &f->smram_region, 1);
>> +    memory_region_set_enabled(&f->smram_region, false);
>> +    init_pam(dev, f->ram_memory, f->system_memory, f->pci_address_space,
>> +             &f->pam_regions[0], PAM_BIOS_BASE, PAM_BIOS_SIZE);
>> +    for (i = 0; i < 12; ++i) {
>> +        init_pam(dev, f->ram_memory, f->system_memory, f->pci_address_space,
>> +                 &f->pam_regions[i+1], PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE,
>> +                 PAM_EXPAN_SIZE);
>> +    }
>> +
>> +    /* 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. */
>> +    piix3 = DO_UPCAST(PIIX3State, dev,
>> +            pci_create_simple_multifunction(b, -1, true, "PIIX3-xen"));
>> +    pci_bus_irqs(b, xen_piix3_set_irq, xen_pci_slot_get_pirq,
>> +            piix3, XEN_PIIX_NUM_PIRQS);
>> +    piix3->pic = pic;
>> +    *isa_bus = ISA_BUS(qdev_get_child_bus(DEVICE(piix3), "isa.0"));
>> +
>> +    *piix3_devfn = piix3->dev.devfn;
>> +
>> +    ram_size = ram_size / 8 / 1024 / 1024;
>> +    if (ram_size > 255) {
>> +        ram_size = 255;
>> +    }
>> +    d->config[0x57] = ram_size;
>> +
>> +    i440fx_update_memory_mappings(f);
>> +
>> +    return b;
>> +}
>
> Too much copy-paste. Please refactor to avoid code duplication.

Okay.

> Is the only difference here the use of TYPE_I440FX_XEN_PCI_DEVICE?

Yes.

> Then you can pass type in as a parameter to a common static sub-function.

I'm fine but as I remember Paolo don't like we intervene a common 
function. And we'll introduce something specific to IGD, like that faked 
PCIe device.

Thanks
Tiejun

>
>> +
>>   PCIBus *find_i440fx(void)
>>   {
>>       PCIHostState *s = OBJECT_CHECK(PCIHostState,
>> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
>> index 1c0c382..51656d9 100644
>> --- a/include/hw/i386/pc.h
>> +++ b/include/hw/i386/pc.h
>> @@ -239,6 +239,16 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
>>                       MemoryRegion *pci_memory,
>>                       MemoryRegion *ram_memory);
>>
>> +PCIBus *xen_igd_i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
>> +                    ISABus **isa_bus, qemu_irq *pic,
>> +                    MemoryRegion *address_space_mem,
>> +                    MemoryRegion *address_space_io,
>> +                    ram_addr_t ram_size,
>> +                    ram_addr_t below_4g_mem_size,
>> +                    ram_addr_t above_4g_mem_size,
>> +                    MemoryRegion *pci_memory,
>> +                    MemoryRegion *ram_memory);
>> +
>>   PCIBus *find_i440fx(void);
>>   /* piix4.c */
>>   extern PCIDevice *piix4_dev;
>> --
>> 1.9.1
>
>
Michael S. Tsirkin July 30, 2014, 5:46 p.m. UTC | #3 
On Wed, Jul 30, 2014 at 04:24:25PM +0800, Chen, Tiejun wrote:
> On 2014/7/29 19:19, Michael S. Tsirkin wrote:
> >On Thu, Jul 24, 2014 at 07:30:28PM +0800, Tiejun Chen wrote:
> >>This is almost same as an original i440fx_init but just
> >>work with that xen igd host bridge to passthrough.
> >>
> >>Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
> >>---
> >>  hw/pci-host/piix.c   | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  include/hw/i386/pc.h | 10 +++++++
> >>  2 files changed, 89 insertions(+)
> >>
> >>diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
> >>index 9feddf5..7ef08d7 100644
> >>--- a/hw/pci-host/piix.c
> >>+++ b/hw/pci-host/piix.c
> >>@@ -407,6 +407,85 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
> >>      return b;
> >>  }
> >>
> >>+PCIBus *xen_igd_i440fx_init(PCII440FXState **pi440fx_state,
> >>+                    int *piix3_devfn,
> >>+                    ISABus **isa_bus, qemu_irq *pic,
> >>+                    MemoryRegion *address_space_mem,
> >>+                    MemoryRegion *address_space_io,
> >>+                    ram_addr_t ram_size,
> >>+                    ram_addr_t below_4g_mem_size,
> >>+                    ram_addr_t above_4g_mem_size,
> >>+                    MemoryRegion *pci_address_space,
> >>+                    MemoryRegion *ram_memory)
> >>+{
> >>+    DeviceState *dev;
> >>+    PCIBus *b;
> >>+    PCIDevice *d;
> >>+    PCIHostState *s;
> >>+    PIIX3State *piix3;
> >>+    PCII440FXState *f;
> >>+    unsigned i;
> >>+    I440FXState *i440fx;
> >>+
> >>+    dev = qdev_create(NULL, TYPE_I440FX_PCI_HOST_BRIDGE);
> >>+    s = PCI_HOST_BRIDGE(dev);
> >>+    b = pci_bus_new(dev, NULL, pci_address_space,
> >>+                    address_space_io, 0, TYPE_PCI_BUS);
> >>+    s->bus = b;
> >>+    object_property_add_child(qdev_get_machine(), "i440fx", OBJECT(dev), NULL);
> >>+    qdev_init_nofail(dev);
> >>+
> >>+    d = pci_create_simple(b, 0, TYPE_I440FX_XEN_PCI_DEVICE);
> >>+    *pi440fx_state = I440FX_XEN_PCI_DEVICE(d);
> >>+    f = *pi440fx_state;
> >>+    f->system_memory = address_space_mem;
> >>+    f->pci_address_space = pci_address_space;
> >>+    f->ram_memory = ram_memory;
> >>+
> >>+    i440fx = I440FX_PCI_HOST_BRIDGE(dev);
> >>+    i440fx->pci_info.w32.begin = below_4g_mem_size;
> >>+
> >>+    /* setup pci memory mapping */
> >>+    pc_pci_as_mapping_init(OBJECT(f), f->system_memory,
> >>+                           f->pci_address_space);
> >>+
> >>+    memory_region_init_alias(&f->smram_region, OBJECT(d), "smram-region",
> >>+                             f->pci_address_space, 0xa0000, 0x20000);
> >>+    memory_region_add_subregion_overlap(f->system_memory, 0xa0000,
> >>+                                        &f->smram_region, 1);
> >>+    memory_region_set_enabled(&f->smram_region, false);
> >>+    init_pam(dev, f->ram_memory, f->system_memory, f->pci_address_space,
> >>+             &f->pam_regions[0], PAM_BIOS_BASE, PAM_BIOS_SIZE);
> >>+    for (i = 0; i < 12; ++i) {
> >>+        init_pam(dev, f->ram_memory, f->system_memory, f->pci_address_space,
> >>+                 &f->pam_regions[i+1], PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE,
> >>+                 PAM_EXPAN_SIZE);
> >>+    }
> >>+
> >>+    /* 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. */
> >>+    piix3 = DO_UPCAST(PIIX3State, dev,
> >>+            pci_create_simple_multifunction(b, -1, true, "PIIX3-xen"));
> >>+    pci_bus_irqs(b, xen_piix3_set_irq, xen_pci_slot_get_pirq,
> >>+            piix3, XEN_PIIX_NUM_PIRQS);
> >>+    piix3->pic = pic;
> >>+    *isa_bus = ISA_BUS(qdev_get_child_bus(DEVICE(piix3), "isa.0"));
> >>+
> >>+    *piix3_devfn = piix3->dev.devfn;
> >>+
> >>+    ram_size = ram_size / 8 / 1024 / 1024;
> >>+    if (ram_size > 255) {
> >>+        ram_size = 255;
> >>+    }
> >>+    d->config[0x57] = ram_size;
> >>+
> >>+    i440fx_update_memory_mappings(f);
> >>+
> >>+    return b;
> >>+}
> >
> >Too much copy-paste. Please refactor to avoid code duplication.
> 
> Okay.
> 
> >Is the only difference here the use of TYPE_I440FX_XEN_PCI_DEVICE?
> 
> Yes.
> 
> >Then you can pass type in as a parameter to a common static sub-function.
> 
> I'm fine but as I remember Paolo don't like we intervene a common function.
> And we'll introduce something specific to IGD, like that faked PCIe device.
> 
> Thanks
> Tiejun

Exactly, so in this way, there is no "if (xen-igd-pt)" in common code.

> >
> >>+
> >>  PCIBus *find_i440fx(void)
> >>  {
> >>      PCIHostState *s = OBJECT_CHECK(PCIHostState,
> >>diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> >>index 1c0c382..51656d9 100644
> >>--- a/include/hw/i386/pc.h
> >>+++ b/include/hw/i386/pc.h
> >>@@ -239,6 +239,16 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
> >>                      MemoryRegion *pci_memory,
> >>                      MemoryRegion *ram_memory);
> >>
> >>+PCIBus *xen_igd_i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
> >>+                    ISABus **isa_bus, qemu_irq *pic,
> >>+                    MemoryRegion *address_space_mem,
> >>+                    MemoryRegion *address_space_io,
> >>+                    ram_addr_t ram_size,
> >>+                    ram_addr_t below_4g_mem_size,
> >>+                    ram_addr_t above_4g_mem_size,
> >>+                    MemoryRegion *pci_memory,
> >>+                    MemoryRegion *ram_memory);
> >>+
> >>  PCIBus *find_i440fx(void);
> >>  /* piix4.c */
> >>  extern PCIDevice *piix4_dev;
> >>--
> >>1.9.1
> >
> >
diff mbox

Patch

diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
index 9feddf5..7ef08d7 100644
--- a/hw/pci-host/piix.c
+++ b/hw/pci-host/piix.c
@@ -407,6 +407,85 @@  PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
     return b;
 }
 
+PCIBus *xen_igd_i440fx_init(PCII440FXState **pi440fx_state,
+                    int *piix3_devfn,
+                    ISABus **isa_bus, qemu_irq *pic,
+                    MemoryRegion *address_space_mem,
+                    MemoryRegion *address_space_io,
+                    ram_addr_t ram_size,
+                    ram_addr_t below_4g_mem_size,
+                    ram_addr_t above_4g_mem_size,
+                    MemoryRegion *pci_address_space,
+                    MemoryRegion *ram_memory)
+{
+    DeviceState *dev;
+    PCIBus *b;
+    PCIDevice *d;
+    PCIHostState *s;
+    PIIX3State *piix3;
+    PCII440FXState *f;
+    unsigned i;
+    I440FXState *i440fx;
+
+    dev = qdev_create(NULL, TYPE_I440FX_PCI_HOST_BRIDGE);
+    s = PCI_HOST_BRIDGE(dev);
+    b = pci_bus_new(dev, NULL, pci_address_space,
+                    address_space_io, 0, TYPE_PCI_BUS);
+    s->bus = b;
+    object_property_add_child(qdev_get_machine(), "i440fx", OBJECT(dev), NULL);
+    qdev_init_nofail(dev);
+
+    d = pci_create_simple(b, 0, TYPE_I440FX_XEN_PCI_DEVICE);
+    *pi440fx_state = I440FX_XEN_PCI_DEVICE(d);
+    f = *pi440fx_state;
+    f->system_memory = address_space_mem;
+    f->pci_address_space = pci_address_space;
+    f->ram_memory = ram_memory;
+
+    i440fx = I440FX_PCI_HOST_BRIDGE(dev);
+    i440fx->pci_info.w32.begin = below_4g_mem_size;
+
+    /* setup pci memory mapping */
+    pc_pci_as_mapping_init(OBJECT(f), f->system_memory,
+                           f->pci_address_space);
+
+    memory_region_init_alias(&f->smram_region, OBJECT(d), "smram-region",
+                             f->pci_address_space, 0xa0000, 0x20000);
+    memory_region_add_subregion_overlap(f->system_memory, 0xa0000,
+                                        &f->smram_region, 1);
+    memory_region_set_enabled(&f->smram_region, false);
+    init_pam(dev, f->ram_memory, f->system_memory, f->pci_address_space,
+             &f->pam_regions[0], PAM_BIOS_BASE, PAM_BIOS_SIZE);
+    for (i = 0; i < 12; ++i) {
+        init_pam(dev, f->ram_memory, f->system_memory, f->pci_address_space,
+                 &f->pam_regions[i+1], PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE,
+                 PAM_EXPAN_SIZE);
+    }
+
+    /* 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. */
+    piix3 = DO_UPCAST(PIIX3State, dev,
+            pci_create_simple_multifunction(b, -1, true, "PIIX3-xen"));
+    pci_bus_irqs(b, xen_piix3_set_irq, xen_pci_slot_get_pirq,
+            piix3, XEN_PIIX_NUM_PIRQS);
+    piix3->pic = pic;
+    *isa_bus = ISA_BUS(qdev_get_child_bus(DEVICE(piix3), "isa.0"));
+
+    *piix3_devfn = piix3->dev.devfn;
+
+    ram_size = ram_size / 8 / 1024 / 1024;
+    if (ram_size > 255) {
+        ram_size = 255;
+    }
+    d->config[0x57] = ram_size;
+
+    i440fx_update_memory_mappings(f);
+
+    return b;
+}
+
 PCIBus *find_i440fx(void)
 {
     PCIHostState *s = OBJECT_CHECK(PCIHostState,
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 1c0c382..51656d9 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -239,6 +239,16 @@  PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
                     MemoryRegion *pci_memory,
                     MemoryRegion *ram_memory);
 
+PCIBus *xen_igd_i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
+                    ISABus **isa_bus, qemu_irq *pic,
+                    MemoryRegion *address_space_mem,
+                    MemoryRegion *address_space_io,
+                    ram_addr_t ram_size,
+                    ram_addr_t below_4g_mem_size,
+                    ram_addr_t above_4g_mem_size,
+                    MemoryRegion *pci_memory,
+                    MemoryRegion *ram_memory);
+
 PCIBus *find_i440fx(void);
 /* piix4.c */
 extern PCIDevice *piix4_dev;