Re: [Xen-devel] [RFC + Queries] Flow of PCI passthrough in ARM

[manish jaggi <manishjaggi.oss@xxxxxxxxx>]

On 20 October 2014 20:24, Stefano Stabellini
<stefano.stabellini@xxxxxxxxxxxxx> wrote:
> On Mon, 20 Oct 2014, manish jaggi wrote:
>> On 8 October 2014 20:21, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> 
>> wrote:
>> > On Wed, Oct 08, 2014 at 07:17:48PM +0530, manish jaggi wrote:
>> >> On 8 October 2014 19:15, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
>> >> > On Wed, 2014-10-08 at 19:07 +0530, manish jaggi wrote:
>> >> >> Thanks for replying. As detailed in this thread, I need to create a
>> >> >> hypercall that would send the following information to Xen at the time
>> >> >> of PCI attach
>> >> >> { sbdf , domU sbdf, domainId }.
>> >> >> I am not able to find a way to get the domU sbdf from dom0 at the time
>> >> >> of pci-attach.
>> >> >
>> >> > I think it would need to be done by the pciback driver in the dom0
>> >> > kernel, which AFAIK is the thing which consistently knows both physical
>> >> > and virtual sbdf for a given assigned device.
>> >> >
>> >> > Ian.
>> >> >
>> >> Correct, can you point out which data structure holds the domU sbdf
>> >> corresponding to the actual sbdf in pciback.
>> >
>> > See 'xen_pcibk_export_device' or 'xen_pcibk_publish_pci_root'
>> > is that what you are referring to?
>>
>> Xen docs also mention about xen-pciback.passthrough=1. If I set this
>> in dom0 i see that the device is enumerated as the same sbdf in domU,
>> but
>> a) it is not shown in lspci
>> b) no front-back communication is done for reading devices configuration 
>> space
>> .
>> Is option useful / fully implemented for ARM ?
>
> I don't think this option is very useful. I wouldn't worry about it for
> now.

Stefano / Ian / Konard / Julien,

Attached is a first raw code FYI RFC Patches of PCI passthrough support on ARM.
- Linux Patch (3.18)
- Xen Patch  (4.5 staging)
---(Smmu changes not included, thats a separate patch altogether)
This patches show the logic, at places need of improvements in code
organization/quality. I wanted to share to get initial comments.
This is working with SRIOV as well.

Please have a look and let me know your positive comments

Attachment: 0002-Removing-X86-as-a-dependency-on-XEN_PCI_FRONTEND-and.patch
Description: Binary data

Attachment: 0005-PCI-passthrough-support-for-Xen.patch
Description: Binary data

Attachment: 0002-SMMU-fix-sbdf-patch.patch
Description: Binary data

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