Re: [Bugfix 0/3] Xen IRQ related hotfixes for v3.19

[Stefan Bader]

On 09.02.2015 13:29, Stefan Bader wrote:
> On 09.02.2015 13:12, Jiang Liu wrote:
>> On 2015/2/9 17:47, Stefan Bader wrote:
>>> On 05.02.2015 21:07, Sander Eikelenboom wrote:
>>>>
>>>> Tuesday, January 20, 2015, 3:21:04 AM, you wrote:
>>>>
>>>>> Hi Thomas,
>>>>>         This patch set includes three hotfixes related Xen IRQ for v3.19.
>>>>> Sorry for the long delay to get these two regressions fixed, it really
>>>>> cost me some time to read and understand Xen IRQ code.
>>>>
>>>>> Patch 1 fixes the failure to register ACPI SCI interrupt on Xen
>>>>> domain0 by reworking acpi_gsi_to_irq(). I will backport it to v3.18
>>>>> too once it reaches the mainstream kernel.
>>>>
>>>>> Patch 2 fixes the regression in Xen PCI device passthrough(pciback).
>>>>> It's a temporary solution, I will send the formal fix for v3.20 and
>>>>> it has passed tests too.
>>>>
>>>>> Patch 3 fixes an issue found when reading code. There's no real bug
>>>>> reports related to this issue yet.
>>>>
>>>>> Great thanks to Konrad and Sander for testing fixes for these regressions.
>>>>
>>>>> Regards,
>>>>> Gerry
>>>>
>>>> Hi Gerry,
>>>>
>>>> Since these patches now are: tested, reviewed and have landed into mainline,
>>>> could you also provide the backports for 3.17 and 3.18 where required ?
>>>
>>> This would be my attempt of backporting those to 3.18 (I have not tried whether
>>> they would apply to 3.17 as well). Those seem to work when test-booting and
>>> Sander said he will give them a try as well. But better check yourself I did not
>>> mess anything up while backporting. One of the three patches seemed not to be
>>> required at all.
>> I'm backporting them too, but now I will give up my patches:)
>>
>> The first one is a must, which should be applied to 3.17 and 3.18.
>> The second one doesn't apply to 3.17 or 3.18.
>> The third may be applied to v3.17 and v3.18, but it shouldn't be applied
>> according to the stable-kernel doc because no user reports such a bug yet.
> 
> Hm, ok. So maybe I should retry with only patch#1 and verify that alone gets
> around the acpi irq and the usb problems, too. Though interestingly from the
> history, the acpi irq I saw in 3.17 while the usb devices started to fail with
> 3.18. I will let you know in a bit. Just want to finish another bisect first.

So it looks like patch #1 indeed does fix both the acpi irq and my usb devices.
Sander, do you want to verify that variant, too?

The only odd thing left in a 3.18 with the fix (regardless of using patch #1
only or patches #1 and #3) is that the ahci driver shows up with its pci bus
number in /proc/interrupts. But that does not seem to have any relevant downside
(cannot try 3.19 on that box right now for other reasons).

-Stefan

...
# 57: 12441  0    0    0  xen-pirq-msi       0000:00:1f.2
#                                            (used to be ahci)

> 
> -Stefan
> 
>> Regards
>> Gerry
>>>
>>> -Stefan
>>>
>>>>
>>>> The number of people running into these (subtle) issues with these stable
>>>> kernels seems to be steadily increasing.
>>>>
>>>> --
>>>> Sander
>>>>
>>>>> Jiang Liu (3):
>>>>>   xen/pci: Kill function xen_setup_acpi_sci()
>>>>>   xen/irq, ACPI: Fix regression in xen PCI passthrough caused by
>>>>>     cffe0a2b5a34
>>>>>   xen/irq: Override ACPI IRQ management callback __acpi_unregister_gsi
>>>>
>>>>>  arch/x86/include/asm/acpi.h |    1 +
>>>>>  arch/x86/kernel/acpi/boot.c |   26 +++++++++++------------
>>>>>  arch/x86/pci/xen.c          |   49 ++-----------------------------------------
>>>>>  drivers/acpi/pci_irq.c      |    1 -
>>>>>  4 files changed, 16 insertions(+), 61 deletions(-)
>>>>
>>>>
>>>
> 
>

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