Re: [Xen-devel] [PATCH v9 10/12] x86/xen: Bypass intr mode setup in enlighten_pv system

[Dou Liyang]

Hi Juergen,

At 09/13/2017 05:45 PM, Juergen Gross wrote:
> On 13/09/17 11:12, Dou Liyang wrote:
> > XEN PV overrides smp_prepare_cpus(). xen_pv_smp_prepare_cpus()
> > initializes interrupts in the XEN PV specific way and does not invoke
> > native_smp_prepare_cpus(). As a consequence, x86_init.intr_mode_init() is
> > not invoked either.
> >
> > The invocation of x86_init.intr_mode_init() will be moved from
> > native_smp_prepare_cpus() in a follow up patch to solve <INSERT
> > REASON/PROBLEM>.
>
> I asked you to be more specific here before. So: what will be solved?
> Can I select a problem I like? ;-)

Oops, I am sorry I missed it. I will modify it.

...to solve the dump-capture kernel hangs, if there is a notsc option
in its command line.

> > That move would cause the invocation of x86_init.intr_mode_init() for XEN
> > PV platforms. To prevent that, override the default x86_init.intr_mode_init()
> > callback with a noop().
> >
> > [Rewrited by Thomas Gleixner <tglx@xxxxxxxxxxxxx>]
>
> Rewritten?

Yeah, yeah. poor english skill :-).

> > Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
> > Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
> > Cc: boris.ostrovsky@xxxxxxxxxx
> > Cc: Juergen Gross <jgross@xxxxxxxx>
>
> Regarding the changes below:
>
> Acked-by: Juergen Gross <jgross@xxxxxxxx>

Thank you for your acked, I will re-post it.

Thanks,
	dou.
> Juergen
>
> > ---
> >  arch/x86/xen/enlighten_pv.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
> > index ae2a2e2..934dc7f 100644
> > --- a/arch/x86/xen/enlighten_pv.c
> > +++ b/arch/x86/xen/enlighten_pv.c
> > @@ -1232,6 +1232,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
> >  	x86_platform.get_nmi_reason = xen_get_nmi_reason;
> >
> >  	x86_init.resources.memory_setup = xen_memory_setup;
> > +	x86_init.irqs.intr_mode_init	= x86_init_noop;
> >  	x86_init.oem.arch_setup = xen_arch_setup;
> >  	x86_init.oem.banner = xen_banner;