Re: Kernel Panics on Xen ARM64 for Domain0 and Guest

[Julien Grall]

On 28/11/16 15:29, tj@xxxxxxxxxx wrote:
> Hello,

Hello,

> On Mon, Nov 28, 2016 at 11:59:15AM +0000, Julien Grall wrote:
> > > commit 3ca45a46f8af8c4a92dd8a08eac57787242d5021
> > > percpu: ensure the requested alignment is power of two
> >
> > It would have been useful to specify the tree used. In this case,
> > this commit comes from linux-next.
>
> I'm surprised this actually triggered.
>
> > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > index f193414..4986dc0 100644
> > --- a/arch/arm/xen/enlighten.c
> > +++ b/arch/arm/xen/enlighten.c
> > @@ -372,8 +372,7 @@ static int __init xen_guest_init(void)
> >          * for secondary CPUs as they are brought up.
> >          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
> >          */
> > -       xen_vcpu_info = __alloc_percpu(sizeof(struct vcpu_info),
> > -                                              sizeof(struct vcpu_info));
> > +       xen_vcpu_info = alloc_percpu(struct vcpu_info);
> >         if (xen_vcpu_info == NULL)
> >                 return -ENOMEM;
>
> Yes, this looks correct.  Can you please cc stable too?  percpu
> allocator never supported alignments which aren't power of two and has
> always behaved incorrectly with alignments which aren't power of two.

I will send the patch soon with stable CCed.

Regards,

--
Julien Grall