[PATCH v3 2/2] pseries/eeh: Add Pseries pcibios_bus_add_device

[Alexey Kardashevskiy]

On 18/10/17 01:11, Bryant G. Ly wrote:
> Adding Juan back into the cc: jjalvare at linux.vnet.ibm.com
> 
> 
> On 10/16/17 10:38 PM, Michael Ellerman wrote:
>> "Bryant G. Ly" <bryantly at linux.vnet.ibm.com> writes:
>>> On 10/12/17 1:29 PM, Bjorn Helgaas wrote:
>> ...
>>>> If that's the case, how to you ever bind a driver to these VFs?  The
>>>> changelog says you don't want VF drivers to load *immediately*, so I
>>>> assume you do want them to load eventually.
>>>>
>>> The VF's that get dynamically created within the configure SR-IOV call, 
>>> on the Pseries Platform, wont be matched with a driver. - We do not
>>> want it to match.
>>>
>>> The Power Hypervisor will load the VFs. The VF's will get assigned(by 
>>> the user) > via the HMC or Novalink in this environment which will
>>> then trigger PHYP to load the VF device node to the device tree.
>> What about the other "Power Hypervisor"? ie. KVM running on Power.
> This path is only exercised when configuring SR-IOV for Pseries LPAR,
> therefore it will not affect PowerNV or KVM(opal).

PowerNV KVM guest is a pseries machine so this code will execute there.

> Which is the reason for
> the separation of calls to the machine dependent stuff.
>> We also use the pseries platform when running under KVM.
>>
>> cheers
>>
> If anyone plans to enable SR-IOV on Pseries platform, firmware must provide the
> resources to enable the VFs and map them with system resources.

This is what the PowerNV platform does.

> A new version
> of the PAPR Document will be added to document these system resources.

The guest simply gets yet another PCI device, how is IOV different here?

In regard of EEH, the API does not change afaik, it is up to the hypervisor
(KVM+QEMU) to handle IOV case correctly.


> Lastly,
> we were not aware that there is an intention to enable SR-IOV in adapters assigned
> to a VM with Pseries running on KVM.

There is no any special enablement of IOV for a VM on powernv, once
configured in the powernv host, we can just pass VFs to QEMU and therefore
to a pseries guest, it is just a normal PCI device.

Do you assign a PF to a VM and create VFs from inside the VM? Or only pHyp
is allowed to do that? Sorry, I know nothing about pHyp on this matter.


> Furthermore, this could be left as a todo
> for the future if this type of configuration is needed.




-- 
Alexey