Re: [Qemu-devel] [Xen-devel] [XEN][RFC PATCH 14/15] xl-parsing: Parse the new option device_models

[Julien Grall <julien.grall@citrix.com>]

On 04/03/2012 02:31 PM, Ian Jackson wrote:
> Stefano Stabellini writes ("Re: [Xen-devel] [XEN][RFC PATCH 14/15] xl-parsing: Parse the new option device_models"):
>    
>> On Mon, 2 Apr 2012, Ian Jackson wrote:
>>      
>>> I don't think this is really a suitable interface.  The PCI space in
>>> the guest is controlled by the device models(s) and the user should
>>> surely specify which devices should be provided by which dms, in terms
>>> of devices not in terms of PCI space.
>>>        
>>
>> Julien added a name parameter to select the device, maybe we need
>> something clearer?
>> Specifying the PCI address is important, because we have to make sure
>> the PCI addresses of the devices remain the same in a given VM across
>> multiple boots.
>>      
> Are the PCI addresses not assigned in a deterministic fashion by code
> in qemu-dm, in this case in the qemu-dm which is emulating the pci
> bridge ?  If not then that needs to be fixed, surely ?
>    
Indeed but each QEMU emulate a subset of the hardware.
So how QEMU can know the available PCI addresses ?
I think that toolstack must allocate the BDF, otherwise we need to have
communication between each qemu-dm.