Re: [v6,3/3] x86/smpboot: Fix __max_logical_packages estimate

From: Prarit Bhargava
Date: Wed Feb 07 2018 - 14:31:08 EST




On 02/07/2018 02:26 PM, Simon Gaiser wrote:
> Prarit Bhargava:
>> On 02/07/2018 01:44 PM, Simon Gaiser wrote:

<snip>

>>> This breaks booting as Xen PV domain for me. The problem seems to be
>>> that native_smp_cpus_done() is never called on a PV domain. So
>>> __max_logical_packages is uninitialized and this leads to a NULL
>>> pointer dereference in coretemp.
>>>
>>
>> I'll see if I can figure out a way to test that.
>
> Ok, thanks. If you need some logs, or if I should test something just
> ask.
>

Thanks, I may send you a patch off-list to test.

>> Does 947134d9b00f
>> ("x86/smpboot: Do not use smp_num_siblings in __max_logical_packages
>> calculation") help?
>
> No.
>

Yeah, your description was absolutely correct. native_smp_cpus_done() is only
called for HVM guests and not PV. I'm going to think about that and send you a
patch in a bit.

P.