Re: [PATCH] PCI: Mark broken INTx masking for BENET devices

[Gavin Shan <gwshan@linux.vnet.ibm.com>]

On Fri, Jan 09, 2015 at 07:40:08AM +0000, Venkat Duvvuru wrote:
>> >
>> > Venkat, On IBM's Power7 box, I passed through following adpater to guest
>> with
>> > following
>> ...
>> >
>> > Steps to recreate the issue
>> > ===========================
>> >
>> > 1. Configure the NIC and ping it from external.
>> > 2. Inject EEH error by running following command in host side. After about
>> >    20 seconds, I got following message from host side. With the patch
>> applied
>> >    to host kernel, I didn't see the warning messages:
>> 
>> This seems really dubious and I don't see any justification at all for declaring
>> DisINTx broken for all devices for the vendor.  Typically to call DisINTx broken
>> for a given device, you can just boot the guest with pci=nomsi to force INTx
>> to be used.  If that works, then DisINTx masking works.  If you require EEH
>> injection to to trigger this, then the problem is more likely some containment
>> issue during EEH recovery.  Thanks,
>> 
>> Alex
>Yes I agree with Alex. 
>pci=nomsi is what exactly we did to see if DisINTx is broken or not and DisINTx works fine in our setup.
>I think, we need to analyze this EEH injection scenario further, to root cause the problem.
>We will post you updates on our findings after the analysis.

Thanks for suggestions. I'll do more experiments to locate the EEH. With the older
QEMU version, I didn't find this issue, so I guess it would be introduced by recent
QEMU VFIO changes.

Note: pci=nomsi didn't give me usable console from the guest side. I don't know why
yet. Need some time to investigate.

Thanks,
Gavin