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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Alexander Graf <agraf@suse.de>, benh@kernel.crashing.org, paulus@samba.org
Subject: Re: [PATCH 1/4] KVM: PPC: BOOK3S: PR: Emulate virtual timebase
 register
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Date: Fri, 06 Jun 2014 21:57:37 +0530
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Alexander Graf <agraf@suse.de> writes:

> On 05.06.14 14:08, Aneesh Kumar K.V wrote:
>> virtual time base register is a per VM, per cpu register that needs
>> to be saved and restored on vm exit and entry. Writing to VTB is not
>> allowed in the privileged mode.
>>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>
> For some reason BUG() doesn't always trigger the "execution stops here" 
> logic in gcc. So I've squashed this patch into yours.
>
>
> Alex
>
>
> diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
> index 3e7085d..99de6ad 100644
> --- a/arch/powerpc/include/asm/reg.h
> +++ b/arch/powerpc/include/asm/reg.h
> @@ -1206,6 +1206,7 @@ static inline unsigned long mfvtb (void)
>        * capture that.
>        */
>       BUG();
> +    return 0;
>   }
>
>   #ifdef __powerpc64__

you can then drop the include header change. ie, 

#include <asm/bug.h>

-aneesh