Re: [PATCH][tip] x86/paravirt: Make the virt_spin_lock_key setup after jump_label_init()

[Juergen Gross]

On 28/10/17 12:55, Borislav Petkov wrote:
> On Fri, Oct 27, 2017 at 07:25:04PM +0200, Juergen Gross wrote:
>>>> This is assuming CPU 0 is the boot cpu. I think you want boot_cpu_data.cpu_index here or whatever is used on xen to identify the BSP reliably. 
>>>
>>> It seems both PV and PVHVM call xen_init_lock_cpu(0) so 0 here is
>>> Linux's idea of CPU id, not Xen's.
>>>
>>> In case Xen's idea is needed xen_vcpu_id mapping should be used. But I
>>> don't think it's the case here.
>>>
>>
>> Correct.
> 
> If it is Linux's idea of the BSP, then you need to check against
> boot_cpu_data.cpu_index.

The idea is to set the static key on the first call of
xen_init_lock_cpu(). As this first call is done with 0 as parameter
the correct check is against 0.


Juergen