linux-kernel - Re: [PATCH][tip] x86/paravirt: Make the virt_spin_lock_key setup after jump_label

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Date:   Sat, 28 Oct 2017 12:55:46 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Juergen Gross <jgross@...e.com>
Cc:     Vitaly Kuznetsov <vkuznets@...hat.com>,
        Dou Liyang <douly.fnst@...fujitsu.com>,
        linux-kernel@...r.kernel.org, x86@...nel.org,
        xen-devel@...ts.xenproject.org, tglx@...utronix.de,
        mingo@...hat.com, hpa@...or.com, boris.ostrovsky@...cle.com,
        luto@...nel.org
Subject: Re: [PATCH][tip] x86/paravirt: Make the virt_spin_lock_key setup
 after jump_label_init()

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.

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
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