attach a pcie root port as hostdev

[Jiatong Shen]

Thank you very much..

On Wed, Aug 4, 2021 at 10:39 PM Laine Stump <laine at redhat.com> wrote:

>
>
> On 8/4/21 3:21 AM, Jiatong Shen wrote:
> > Hello community,
> >
> > I am working on plugging a xilinx fpga card as a hostdev.  This fpga
> > card has 2 functions, each has a different role, for some reason, I
> > would like to attach both of them but do not want to attach them
> > separately, so I have tried to attach a pci bridge where fpga cards
> > connect to. but got the following  error,
> >
> > error: Failed to attach device from bridge.xml
> >
> error: internal error: Non-endpoint PCI devices cannot be assigned to guests
>
> >
> >
> > so, my question is is it possible to attach a pci-bridge as hostdev?
> > thank you.
>
> No, it isn't possible. VFIO only supports attaching endpoint devices.
>
> You will need to attach each of your endpoint devices separately. (If
> the issue is that you want both devices to show up on the same root port
> in the guest, that is easily accomplished by manually setting the
> guest-side pci address of the devices to have the same same bus/slot,
> but different function; this does mean that you can't hotplug, but will
> deliver the desired topology. Note that although I've heard of people
> who thought that they needed devices to be on the same slot, I've never
> seen any evidence that this was actually required by any OS or driver)
>
>

-- 

Best Regards,

Jiatong Shen
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