Re: [Qemu-devel] [Xen-devel] [PATCH RFC V1 00/11] Xen PCI Passthrough

[Anthony Liguori <anthony@codemonkey.ws>]

On 10/04/2011 09:58 AM, Avi Kivity wrote:
> On 10/04/2011 04:51 PM, Anthony PERARD wrote:
>> Hi all,
>>
>> This patch series introduce the PCI passthrough for Xen.
>>
>> First, we have HostPCIDevice that help to access one PCI device of the host.
>>
>> Then, there are several additions in the QEMU code. One is qemu_run_one_timer
>> to run a specific timer. It is used by PCI passthrough to run a timer about
>> power management. Another is pci_check_bar_overlap.
>>
>> There are also several change in pci_ids and pci_regs.
>>
>> Last part, but not least, the PCI passthrough device himself. Cut in 3 parts
>> (or file), there is one to take care of the initialisation of a passthrough
>> device. The second one handle everything about the config address space, there
>> are specifics functions for every config register. The third one is to handle
>> MSI.
>>
>> I'm still working on setting a PCI passthrough device through QMP from libxl
>> (xen tool stack). It is just a call to device_add, with the driver parametter
>> hostaddr="0000:00:1b.0".
>>
>> There is some minor things missing:
>> - copyright header
>> - PCI IO space multiplexer
>>
>>
>
> We also have pci passthrough in qemu-kvm (I think based on the same Neocleus
> code). Rather than having two pci assignment implementations, I think we should
> have just one, with the differences (programming the hypervisor) abstracted at
> that level.

I agree in principle but how close is qemu-kvm pci passthrough to a mergable 
state?  Would it make sense to merge the Xen code first and then abstract it?

Regards,

Anthony Liguori

>