Please apply "partially revert "xen: Remove event channel..."

Please apply "partially revert "xen: Remove event channel..."

[Ian Jackson]

tl;dr:
 Please apply

    da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
    partially revert "xen: Remove event channel notification through
      Xen PCI platform device"

 to all stable branches which have a version of the original broken
 commit.  This includes at least 4.9.y.

Background:

osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
...
>  test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass

osstest doesn't consider this a regresion because it looks for
regressions within a branch, and this is the first test of Linux 4.9.
However, this is a regression from the kernel we are currently using.

L1 dom0 console log:
  http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log

It seems to have got stuck halfway through booting.

The message
  (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
shows where osstest timed out on this test, and started its log
capture process (including collecting debug key output).

Complete logs for this job here:
  http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html

Juergen Gross tells me that this is due to the lack of
da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.

Thanks,
Ian.

PS: Stefano, Boris: did you already request a backport of this commit?
If not, why not ?

Re: Please apply "partially revert "xen: Remove event channel..."

[Boris Ostrovsky]

On 04/07/2017 07:58 AM, Ian Jackson wrote:
> tl;dr:
>  Please apply
>
>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
>     partially revert "xen: Remove event channel notification through
>       Xen PCI platform device"
>
>  to all stable branches which have a version of the original broken
>  commit.  This includes at least 4.9.y.
>
> Background:
>
> osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
> ...
>>  test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass
> osstest doesn't consider this a regresion because it looks for
> regressions within a branch, and this is the first test of Linux 4.9.
> However, this is a regression from the kernel we are currently using.
>
> L1 dom0 console log:
>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log
>
> It seems to have got stuck halfway through booting.
>
> The message
>   (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
> shows where osstest timed out on this test, and started its log
> capture process (including collecting debug key output).
>
> Complete logs for this job here:
>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html
>
> Juergen Gross tells me that this is due to the lack of
> da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.
>
> Thanks,
> Ian.
>
> PS: Stefano, Boris: did you already request a backport of this commit?
> If not, why not ?

No, but this should indeed be backported to 4.9+

-boris

Re: Please apply "partially revert "xen: Remove event channel..."

[Stefano Stabellini]

On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
> On 04/07/2017 07:58 AM, Ian Jackson wrote:
> > tl;dr:
> >  Please apply
> >
> >     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
> >     partially revert "xen: Remove event channel notification through
> >       Xen PCI platform device"
> >
> >  to all stable branches which have a version of the original broken
> >  commit.  This includes at least 4.9.y.
> >
> > Background:
> >
> > osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
> > ...
> >>  test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass
> > osstest doesn't consider this a regresion because it looks for
> > regressions within a branch, and this is the first test of Linux 4.9.
> > However, this is a regression from the kernel we are currently using.
> >
> > L1 dom0 console log:
> >   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log
> >
> > It seems to have got stuck halfway through booting.
> >
> > The message
> >   (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
> > shows where osstest timed out on this test, and started its log
> > capture process (including collecting debug key output).
> >
> > Complete logs for this job here:
> >   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html
> >
> > Juergen Gross tells me that this is due to the lack of
> > da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.
> >
> > Thanks,
> > Ian.
> >
> > PS: Stefano, Boris: did you already request a backport of this commit?
> > If not, why not ?
> 
> No, but this should indeed be backported to 4.9+

Boris, are you going to do that?

While we wait for the kernel.org stable maintainers to do the backport,
would it help OSSTest if I backported
da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1 to the linux-arm-xen branch
myself now?

Re: Please apply "partially revert "xen: Remove event channel..."

[Boris Ostrovsky]

On 04/07/2017 01:36 PM, Stefano Stabellini wrote:
> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>> On 04/07/2017 07:58 AM, Ian Jackson wrote:
>>> tl;dr:
>>>  Please apply
>>>
>>>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
>>>     partially revert "xen: Remove event channel notification through
>>>       Xen PCI platform device"
>>>
>>>  to all stable branches which have a version of the original broken
>>>  commit.  This includes at least 4.9.y.
>>>
>>> Background:
>>>
>>> osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
>>> ...
>>>>  test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass
>>> osstest doesn't consider this a regresion because it looks for
>>> regressions within a branch, and this is the first test of Linux 4.9.
>>> However, this is a regression from the kernel we are currently using.
>>>
>>> L1 dom0 console log:
>>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log
>>>
>>> It seems to have got stuck halfway through booting.
>>>
>>> The message
>>>   (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
>>> shows where osstest timed out on this test, and started its log
>>> capture process (including collecting debug key output).
>>>
>>> Complete logs for this job here:
>>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html
>>>
>>> Juergen Gross tells me that this is due to the lack of
>>> da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.
>>>
>>> Thanks,
>>> Ian.
>>>
>>> PS: Stefano, Boris: did you already request a backport of this commit?
>>> If not, why not ?
>> No, but this should indeed be backported to 4.9+
> Boris, are you going to do that?

Is there anything that needs to be done beyond just applying it to 4.9
(4.10 apparently already has it).

-boris


>
> While we wait for the kernel.org stable maintainers to do the backport,
> would it help OSSTest if I backported
> da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1 to the linux-arm-xen branch
> myself now?

Re: Please apply "partially revert "xen: Remove event channel..."

[Stefano Stabellini]

On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
> On 04/07/2017 01:36 PM, Stefano Stabellini wrote:
> > On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
> >> On 04/07/2017 07:58 AM, Ian Jackson wrote:
> >>> tl;dr:
> >>>  Please apply
> >>>
> >>>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
> >>>     partially revert "xen: Remove event channel notification through
> >>>       Xen PCI platform device"
> >>>
> >>>  to all stable branches which have a version of the original broken
> >>>  commit.  This includes at least 4.9.y.
> >>>
> >>> Background:
> >>>
> >>> osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
> >>> ...
> >>>>  test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass
> >>> osstest doesn't consider this a regresion because it looks for
> >>> regressions within a branch, and this is the first test of Linux 4.9.
> >>> However, this is a regression from the kernel we are currently using.
> >>>
> >>> L1 dom0 console log:
> >>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log
> >>>
> >>> It seems to have got stuck halfway through booting.
> >>>
> >>> The message
> >>>   (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
> >>> shows where osstest timed out on this test, and started its log
> >>> capture process (including collecting debug key output).
> >>>
> >>> Complete logs for this job here:
> >>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html
> >>>
> >>> Juergen Gross tells me that this is due to the lack of
> >>> da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.
> >>>
> >>> Thanks,
> >>> Ian.
> >>>
> >>> PS: Stefano, Boris: did you already request a backport of this commit?
> >>> If not, why not ?
> >> No, but this should indeed be backported to 4.9+
> > Boris, are you going to do that?
> 
> Is there anything that needs to be done beyond just applying it to 4.9
> (4.10 apparently already has it).

No, I don't think so. 4.9 already has the offending commit.

Re: Please apply "partially revert "xen: Remove event channel..."

[Boris Ostrovsky]

On 04/07/2017 06:11 PM, Stefano Stabellini wrote:
> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>> On 04/07/2017 01:36 PM, Stefano Stabellini wrote:
>>> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>>>> On 04/07/2017 07:58 AM, Ian Jackson wrote:
>>>>> tl;dr:
>>>>>  Please apply
>>>>>
>>>>>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
>>>>>     partially revert "xen: Remove event channel notification through
>>>>>       Xen PCI platform device"
>>>>>
>>>>>  to all stable branches which have a version of the original broken
>>>>>  commit.  This includes at least 4.9.y.
>>>>>
>>>>> Background:
>>>>>
>>>>> osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
>>>>> ...
>>>>>>  test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass
>>>>> osstest doesn't consider this a regresion because it looks for
>>>>> regressions within a branch, and this is the first test of Linux 4.9.
>>>>> However, this is a regression from the kernel we are currently using.
>>>>>
>>>>> L1 dom0 console log:
>>>>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log
>>>>>
>>>>> It seems to have got stuck halfway through booting.
>>>>>
>>>>> The message
>>>>>   (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
>>>>> shows where osstest timed out on this test, and started its log
>>>>> capture process (including collecting debug key output).
>>>>>
>>>>> Complete logs for this job here:
>>>>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html
>>>>>
>>>>> Juergen Gross tells me that this is due to the lack of
>>>>> da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.
>>>>>
>>>>> Thanks,
>>>>> Ian.
>>>>>
>>>>> PS: Stefano, Boris: did you already request a backport of this commit?
>>>>> If not, why not ?
>>>> No, but this should indeed be backported to 4.9+
>>> Boris, are you going to do that?
>> Is there anything that needs to be done beyond just applying it to 4.9
>> (4.10 apparently already has it).
> No, I don't think so. 4.9 already has the offending commit.


Looks like there will be a new version of the original patch
(72a9b186292) so we should hold off with backport request to 4.9:

https://lists.xenproject.org/archives/html/xen-devel/2017-04/msg01468.html

-boris

Re: Please apply "partially revert "xen: Remove event channel..."

[Juergen Gross]

On 10/04/17 15:47, Boris Ostrovsky wrote:
> On 04/07/2017 06:11 PM, Stefano Stabellini wrote:
>> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>>> On 04/07/2017 01:36 PM, Stefano Stabellini wrote:
>>>> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>>>>> On 04/07/2017 07:58 AM, Ian Jackson wrote:
>>>>>> tl;dr:
>>>>>>  Please apply
>>>>>>
>>>>>>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
>>>>>>     partially revert "xen: Remove event channel notification through
>>>>>>       Xen PCI platform device"
>>>>>>
>>>>>>  to all stable branches which have a version of the original broken
>>>>>>  commit.  This includes at least 4.9.y.
>>>>>>
>>>>>> Background:
>>>>>>
>>>>>> osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
>>>>>> ...
>>>>>>>  test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass
>>>>>> osstest doesn't consider this a regresion because it looks for
>>>>>> regressions within a branch, and this is the first test of Linux 4.9.
>>>>>> However, this is a regression from the kernel we are currently using.
>>>>>>
>>>>>> L1 dom0 console log:
>>>>>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log
>>>>>>
>>>>>> It seems to have got stuck halfway through booting.
>>>>>>
>>>>>> The message
>>>>>>   (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
>>>>>> shows where osstest timed out on this test, and started its log
>>>>>> capture process (including collecting debug key output).
>>>>>>
>>>>>> Complete logs for this job here:
>>>>>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html
>>>>>>
>>>>>> Juergen Gross tells me that this is due to the lack of
>>>>>> da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.
>>>>>>
>>>>>> Thanks,
>>>>>> Ian.
>>>>>>
>>>>>> PS: Stefano, Boris: did you already request a backport of this commit?
>>>>>> If not, why not ?
>>>>> No, but this should indeed be backported to 4.9+
>>>> Boris, are you going to do that?
>>> Is there anything that needs to be done beyond just applying it to 4.9
>>> (4.10 apparently already has it).
>> No, I don't think so. 4.9 already has the offending commit.
> 
> 
> Looks like there will be a new version of the original patch
> (72a9b186292) so we should hold off with backport request to 4.9:
> 
> https://lists.xenproject.org/archives/html/xen-devel/2017-04/msg01468.html

TBH: I'm not convinced by the reasoning why 72a9b186292 has to be
reworked: Do we really care for Xen versions < 4.0 and a theoretical
problem (after all the author admitted the bug isn't being hit in
reality due to a short-circuit in the code)?

And even if we do: I'd rather add another patch to stable later than
keeping a real bug in Linux 4.9 which has been hit at least 3 times
up to now (by Stefano, George and Ian).


Juergen

Re: Please apply "partially revert "xen: Remove event channel..."

[Boris Ostrovsky]

On 04/10/2017 09:57 AM, Juergen Gross wrote:
> On 10/04/17 15:47, Boris Ostrovsky wrote:
>> On 04/07/2017 06:11 PM, Stefano Stabellini wrote:
>>> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>>>> On 04/07/2017 01:36 PM, Stefano Stabellini wrote:
>>>>> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>>>>>> On 04/07/2017 07:58 AM, Ian Jackson wrote:
>>>>>>> tl;dr:
>>>>>>>  Please apply
>>>>>>>
>>>>>>>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
>>>>>>>     partially revert "xen: Remove event channel notification through
>>>>>>>       Xen PCI platform device"
>>>>>>>
>>>>>>>  to all stable branches which have a version of the original broken
>>>>>>>  commit.  This includes at least 4.9.y.
>>>>>>>
>>>>>>> Background:
>>>>>>>
>>>>>>> osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
>>>>>>> ...
>>>>>>>>  test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass
>>>>>>> osstest doesn't consider this a regresion because it looks for
>>>>>>> regressions within a branch, and this is the first test of Linux 4.9.
>>>>>>> However, this is a regression from the kernel we are currently using.
>>>>>>>
>>>>>>> L1 dom0 console log:
>>>>>>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log
>>>>>>>
>>>>>>> It seems to have got stuck halfway through booting.
>>>>>>>
>>>>>>> The message
>>>>>>>   (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
>>>>>>> shows where osstest timed out on this test, and started its log
>>>>>>> capture process (including collecting debug key output).
>>>>>>>
>>>>>>> Complete logs for this job here:
>>>>>>>   http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html
>>>>>>>
>>>>>>> Juergen Gross tells me that this is due to the lack of
>>>>>>> da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Ian.
>>>>>>>
>>>>>>> PS: Stefano, Boris: did you already request a backport of this commit?
>>>>>>> If not, why not ?
>>>>>> No, but this should indeed be backported to 4.9+
>>>>> Boris, are you going to do that?
>>>> Is there anything that needs to be done beyond just applying it to 4.9
>>>> (4.10 apparently already has it).
>>> No, I don't think so. 4.9 already has the offending commit.
>>
>> Looks like there will be a new version of the original patch
>> (72a9b186292) so we should hold off with backport request to 4.9:
>>
>> https://lists.xenproject.org/archives/html/xen-devel/2017-04/msg01468.html
> TBH: I'm not convinced by the reasoning why 72a9b186292 has to be
> reworked: Do we really care for Xen versions < 4.0 and a theoretical
> problem (after all the author admitted the bug isn't being hit in
> reality due to a short-circuit in the code)?

I don't know what the deal is with <4.0 Xen and I am not sure whether we
can boot new-ish Linux on those releases regardless of this specific
issue. I am certainly only testing Xen 4.1+ and have been doing this for
at least last 2-3 years.


>
> And even if we do: I'd rather add another patch to stable later than
> keeping a real bug in Linux 4.9 which has been hit at least 3 times
> up to now (by Stefano, George and Ian).

That would depend on how soon the new patch shows up.

-boris

Re: Please apply "partially revert "xen: Remove event channel..."

[Juergen Gross]

On 10/04/17 17:32, Raslan, KarimAllah wrote:
> 
> Ahmed, Karim Allah
> karahmed@amazon.de
> 
> 
> 
>> On Apr 10, 2017, at 3:57 PM, Juergen Gross <jgross@suse.com> wrote:
>>
>> On 10/04/17 15:47, Boris Ostrovsky wrote:
>>> On 04/07/2017 06:11 PM, Stefano Stabellini wrote:
>>>> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>>>>> On 04/07/2017 01:36 PM, Stefano Stabellini wrote:
>>>>>> On Fri, 7 Apr 2017, Boris Ostrovsky wrote:
>>>>>>> On 04/07/2017 07:58 AM, Ian Jackson wrote:
>>>>>>>> tl;dr:
>>>>>>>> Please apply
>>>>>>>>
>>>>>>>>    da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
>>>>>>>>    partially revert "xen: Remove event channel notification through
>>>>>>>>      Xen PCI platform device"
>>>>>>>>
>>>>>>>> to all stable branches which have a version of the original broken
>>>>>>>> commit.  This includes at least 4.9.y.
>>>>>>>>
>>>>>>>> Background:
>>>>>>>>
>>>>>>>> osstest service owner writes ("[linux-4.9 baseline test] 107238: tolerable FAIL"):
>>>>>>>> ...
>>>>>>>>> test-amd64-amd64-qemuu-nested-intel 13 xen-boot/l1  fail never pass
>>>>>>>> osstest doesn't consider this a regresion because it looks for
>>>>>>>> regressions within a branch, and this is the first test of Linux 4.9.
>>>>>>>> However, this is a regression from the kernel we are currently using.
>>>>>>>>
>>>>>>>> L1 dom0 console log:
>>>>>>>>  http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/huxelrebe0---var-log-xen-osstest-serial-l1.guest.osstest.log
>>>>>>>>
>>>>>>>> It seems to have got stuck halfway through booting.
>>>>>>>>
>>>>>>>> The message
>>>>>>>>  (XEN) *** Serial input -> Xen (type 'CTRL-x' three times to switch input to DOM0)
>>>>>>>> shows where osstest timed out on this test, and started its log
>>>>>>>> capture process (including collecting debug key output).
>>>>>>>>
>>>>>>>> Complete logs for this job here:
>>>>>>>>  http://logs.test-lab.xenproject.org/osstest/logs/107238/test-amd64-amd64-qemuu-nested-intel/info.html
>>>>>>>>
>>>>>>>> Juergen Gross tells me that this is due to the lack of
>>>>>>>> da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1.
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Ian.
>>>>>>>>
>>>>>>>> PS: Stefano, Boris: did you already request a backport of this commit?
>>>>>>>> If not, why not ?
>>>>>>> No, but this should indeed be backported to 4.9+
>>>>>> Boris, are you going to do that?
>>>>> Is there anything that needs to be done beyond just applying it to 4.9
>>>>> (4.10 apparently already has it).
>>>> No, I don't think so. 4.9 already has the offending commit.
>>>
>>>
>>> Looks like there will be a new version of the original patch
>>> (72a9b186292) so we should hold off with backport request to 4.9:
>>>
>>> https://lists.xenproject.org/archives/html/xen-devel/2017-04/msg01468.html
>>
>> TBH: I'm not convinced by the reasoning why 72a9b186292 has to be
>> reworked: Do we really care for Xen versions < 4.0 and a theoretical
>> problem (after all the author admitted the bug isn't being hit in
>> reality due to a short-circuit in the code)?
> 
> IMHO, even if 72a9b186292 has not been reworked we should completely revert it
> not only partially revert it. Before this commit at least kernel 4.9+ would
> work on older Xen versions (< 4.0) while now, it will not even boot.

Just to make sure we understand which Xen versions are to be
supported: which Xen versions are you at Amazon currently using?


Juergen

Re: Please apply "partially revert "xen: Remove event channel..."

[Greg KH]

On Fri, Apr 07, 2017 at 12:58:14PM +0100, Ian Jackson wrote:
> tl;dr:
>  Please apply
> 
>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
>     partially revert "xen: Remove event channel notification through
>       Xen PCI platform device"
> 
>  to all stable branches which have a version of the original broken
>  commit.  This includes at least 4.9.y.

Is this still true?  This long thread is totally confusing, is that what
you really want to have happen?  Anything else?

thanks,

greg k-h

Re: Please apply "partially revert "xen: Remove event channel..."

[Juergen Gross]

On 12/04/17 15:13, Greg KH wrote:
> On Fri, Apr 07, 2017 at 12:58:14PM +0100, Ian Jackson wrote:
>> tl;dr:
>>  Please apply
>>
>>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
>>     partially revert "xen: Remove event channel notification through
>>       Xen PCI platform device"
>>
>>  to all stable branches which have a version of the original broken
>>  commit.  This includes at least 4.9.y.
> 
> Is this still true?  This long thread is totally confusing, is that what
> you really want to have happen?  Anything else?

Please ignore this request. We will send another one to fully revert the
original patch leading to the current situation.


Juergen

Re: Please apply "partially revert "xen: Remove event channel..."

[Greg KH]

On Wed, Apr 12, 2017 at 03:26:53PM +0200, Juergen Gross wrote:
> On 12/04/17 15:13, Greg KH wrote:
> > On Fri, Apr 07, 2017 at 12:58:14PM +0100, Ian Jackson wrote:
> >> tl;dr:
> >>  Please apply
> >>
> >>     da72ff5bfcb02c6ac8b169a7cf597a3c8e6c4de1
> >>     partially revert "xen: Remove event channel notification through
> >>       Xen PCI platform device"
> >>
> >>  to all stable branches which have a version of the original broken
> >>  commit.  This includes at least 4.9.y.
> > 
> > Is this still true?  This long thread is totally confusing, is that what
> > you really want to have happen?  Anything else?
> 
> Please ignore this request. We will send another one to fully revert the
> original patch leading to the current situation.

Now ignored!