Re: Xen 4.2.1 boot failure with IOMMU enabled

["Jan Beulich" <JBeulich@suse.com>]

>>> On 12.02.13 at 12:22, "Jan Beulich" <JBeulich@suse.com> wrote:
>>>> On 12.02.13 at 12:15, povder <povder@gmail.com> wrote:
>> 2013/2/12 Jan Beulich <JBeulich@suse.com>:
>>> With the above, the patch is unlikely to address your problem,
>>> but will likely provide better debugging output. So please
>>> nevertheless try building with that patch included, assuming
>>> the problem first started after you built Xen from a recent
>>> 4.2-testing tree (as opposed to this being plain 4.2.1, in which
>>> case the problem is obviously unrelated to the recent changes
>>> I'm thinking of).
>>>
>> 
>> I haven't built Xen myself, I use binaries from
>> http://au1.mirror.crc.id.au/repo/el6/x86_64/ repository and I guess
>> that builds in this repository are from plain 4.2.1.
>> xl info (when I boot with iommu disabled) shows:
>> xen_major              : 4
>> xen_minor              : 2
>> xen_extra              : .1
>> 
>> I just started using Xen when 4.2.1 already was released so this
>> problem appeared to me from the beginning. I can try with 4.2-testing
>> though.
> 
> No, there's no point I'm afraid. We really need to analyze the
> debugging output to first understand what's missing.

All there is for bus 7 is

(XEN) AMD-Vi: IVHD Device Entry:
(XEN) AMD-Vi:  Type 0x2
(XEN) AMD-Vi:  Dev_Id 0x700
(XEN) AMD-Vi:  Flags 0x0

i.e. a single device at 07:00.0, yet from the register dump at the
crash it's fairly clear that we're talking about 07:00.1 here. I'm
afraid only a firmware update can help you here (or passing
"iommu=off" to Xen); in particular I can't see how we could work
around that problem in software.

Jan