Re: [PATCH v8] interrupts: allow guest to set/clear MSI-X mask bit

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 16/09/2013 12:23, Xu, YongweiX wrote:
>> -----Original Message-----
>> From: Jan Beulich [mailto:JBeulich@suse.com]
>> Sent: Monday, September 16, 2013 5:37 PM
>> To: Joby Poriyath; Xu, YongweiX
>> Cc: Sander Eikelenboom; xen-devel
>> Subject: RE: [Xen-devel] [PATCH v8] interrupts: allow guest to set/clear MSI-X
>> mask bit
>>
>>>>> On 16.09.13 at 10:33, "Xu, YongweiX" <yongweix.xu@intel.com> wrote:
>>> I found your patch (Xen C/S:27480 7843bc3502ae) introduced a new
>>> issue, when I boot up a rhel6.4 guest with assigned a e1000e/igb/ixgbe
>>> PF or VF and more than 1 vcpu, the guest's network will be broken in a
>>> short time and cannot be recovered.
>>> The test machine was SandyBridge-EP and IvyTown-EP.
>> I would be very helpful if you could give some more detail: What specifically
>> doesn't work, logs, ...
>>
>> That's particularly important since, if indeed broken, the patch would need to
>> be reverted from at least the stable trees.
>>
>> Jan
> I've made further test about this issue, the config file as the attachment:rhel6u4.hvm(with qemu-xen), the result as below:
> 1. Boot up rhel6.4 guest with igbvf/ixgbevf/igbpf/ixgbepf/e1000e nic and 1 vcpu, the guest network works fine.
> 2. Boot up rhel6.4 guest with igbvf/ixgbevf/igbpf/ixgbepf/e1000e nic and 2(or more) vcpus, the guest can get IP first, but after about 10~20 seconds, the network will be broken.
> We can see only boot guest with more than 1 vcpu would cause this issue.
>
> Only when boot guest with e1000e nic and 2(2 or more)vcpus it would print call trace log, but I think it's enough to explain that the network broken caused by MSI-X, as the attachment:guest_with_e1000e.log.

And does reverting that specific changeset fix the issue?

I ask, because that change set specifically fixes SRIOV passthrough for
HVM guests using the ixgbevf driver, which was broken by an earlier
security enhancement.

~Andrew