Re: [Xen-devel] Pv_ops Dom0 crash on IBM eServer x3400

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 08.06.12 at 12:19, Alex Moskalenko <mav@xxxxxxxxx> wrote:
> 08.06.2012 11:43, Jan Beulich ÐÐÑÐÑ:
>>>>> On 07.06.12 at 11:29, Alex Moskalenko<mav@xxxxxxxxx>  wrote:
>>> I ran into a trouble when trying to run Xen 4.1.x with pv_ops kernel on
>>> IBM eServer x3400. Without noacpi command line option dom0 kernel
>>> crashes on ACPI initialization. Kermels 2.6.32 (with konrad xen
>>> patches), 3.1, 3.3, Xen 4.1.2 behave the same way. Without hypervisor
>>> all kernels run without any problems.
>> This is an issue that was reported and discussed previously.
>> Fundamentally, it is a firmware problem from my pov: ACPI has
>> _nothing_ to do with the MMIO space used for the IO-APICs of
>> the system once they are under control of the OS. It shouldn't
>> even be reading from them (which iirc was the case in earlier
>> reports), but in your case it looks like it's even writing them. I
>> had been considering to allow Dom0 read access to those pages,
>> but obviously this wouldn't help in your case.
>>
>> Could you extract and supply the ACPI tables of that system, so
>> we can make an attempt at checking whether there is some reason
>> for the firmware writing to the IO-APIC that we didn't think of so
>> far?
> Please see attached archive. Tables are grabbed with acpidump -b under 
> Xen 4.1.2 and patched kernel 2.6.32.

_SB.PCI0._CRS has

                Store (0x2E, IDX)
                And (0xFFFEFFFF, WND, WND)

with

    OperationRegion (Z00D, SystemMemory, 0xFEC80000, 0x0100)
    Field (Z00D, DWordAcc, Lock, Preserve)
    {
        IDX,    32, 
                Offset (0x10), 
        WND,    32
    }

so what the BIOS tries to do is unmask pin 15 of the second
IO-APIC. To me this makes no sense at all (and is definitely
impossible to be sync-ed properly with any OSes accesses to
the IO-APIC registers), but could you nevertheless boot a
native kernel with "apic=debug" and post the full set of boot
messages (the dumps of the IO-APICs being what I'm really
after). Alternatively, "apic_verbosity=debug" passed to Xen
or sending the 'z' debug key would produce similar information.

Jan

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