Re: [PATCH] pci: quirk: Apply APM ACS quirk to XGene devices

[Feng Kan]

>
> I don't know what that means, does the hardware support an equivalent
> to source validation or not?

Yes, source validation is done through the smmu.

  What's the response of the root port if
> the downstream device issues a transaction spoofing devices not within
> the bus number ranges of the bridge?
HW guys informs me there is way to disable transactions between root port.
I will confirm later.

>
>> Alex, the goal here is to enable virtualization to work correctly.
>> Please let me know if the
>> above is sufficient. Much thanks.
>
> Of course, but that means that the hardware vendor is vouching that
> this device provides the equivalent isolation for each of the missing
> components of ACS.  Claiming to have isolation capabilities that don't
> exist would be irresponsible and put users of that hardware at risk.
Agreed, I believe we do have isolation in our case based on the conference
we had today.

> Thanks,
>
> Alex