Re: [Qemu-devel] [v3][PATCH 3/4] xen:hw:pci-host:piix: create host bridge to passthrough

["Chen, Tiejun" <tiejun.chen@intel.com>]

On 2014/8/4 21:50, Michael S. Tsirkin wrote:
> On Thu, Jul 31, 2014 at 08:09:33PM +0800, Tiejun Chen wrote:
>> Implement a pci host bridge specific to passthrough. Actually
>> this just inherits the standard one.
>>
>> This is based on http://patchwork.ozlabs.org/patch/363810/.
>>
>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>> ---
>>   hw/pci-host/piix.c   | 41 +++++++++++++++++++++++++++++++++++++++++
>>   include/hw/i386/pc.h |  2 ++
>>   2 files changed, 43 insertions(+)
>>
>> v3:
>>
>> * Rebase
>>
>> v2:
>>
>> * Just add prefix with XEN_IGD_PASSTHROUGH/xen_igd_passthrough
>>
>> diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
>> index 0cd82b8..26ba1e5 100644
>> --- a/hw/pci-host/piix.c
>> +++ b/hw/pci-host/piix.c
>> @@ -93,6 +93,9 @@ typedef struct PIIX3State {
>>   #define I440FX_PCI_DEVICE(obj) \
>>       OBJECT_CHECK(PCII440FXState, (obj), TYPE_I440FX_PCI_DEVICE)
>>
>> +#define XEN_IGD_PASSTHROUGH_I440FX_PCI_DEVICE(obj) \
>> +    OBJECT_CHECK(PCII440FXState, (obj), TYPE_XEN_IGD_PASSTHROUGH_I440FX_PCI_DEVICE)
>> +
>>   struct PCII440FXState {
>>       /*< private >*/
>>       PCIDevice parent_obj;
>> @@ -303,6 +306,16 @@ static int i440fx_initfn(PCIDevice *dev)
>>       return 0;
>>   }
>>
>> +static int xen_igd_passthrough_i440fx_initfn(PCIDevice *dev)
>> +{
>> +    PCII440FXState *d = XEN_IGD_PASSTHROUGH_I440FX_PCI_DEVICE(dev);
>> +
>> +    dev->config[I440FX_SMRAM] = 0x02;
>> +
>> +    cpu_smm_register(&i440fx_set_smm, d);
>> +    return 0;
>> +}
>> +
>
> This is exactly i440fx_initfn.
> Don't copy and paste code like this, reuse existing functions.
>

We can't reuse i440fx_initfn() simply after we introduce 
XEN_IGD_PASSTHROUGH_I440FX_PCI_DEVICE(). But with a further concern I 
think we also pass type into I440FX_PCI_DEVIC() to index different 
objects here. Please see next version.

Thanks
Tiejun