Subject: Re: [RFC PATCH 06/11] kvm: powerpc: book3s: Add is_hv_enabled to kvmppc_ops

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Mon, 30 Sep 2013 18:26:05 +0530

Alexander Graf <[email-masked]> writes:

> On 27.09.2013, at 15:03, Aneesh Kumar K.V wrote:
>
>> Alexander Graf <[email-masked]> writes:
>> 
>> 
>>>> diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
>>>> index 1abe478..e0229dd 100644
>>>> --- a/arch/powerpc/kvm/book3s_segment.S
>>>> +++ b/arch/powerpc/kvm/book3s_segment.S
>>>> @@ -161,9 +161,14 @@ kvmppc_handler_trampoline_enter_end:
>>>> .global kvmppc_handler_trampoline_exit
>>>> kvmppc_handler_trampoline_exit:
>>>> 
>>>> +#if defined(CONFIG_KVM_BOOK3S_HV)
>>>> +.global kvmppc_interrupt_pr
>>>> +kvmppc_interrupt_pr:
>>>> +	ld	r9, HSTATE_SCRATCH2(r13)
>>>> +#else
>>>> .global kvmppc_interrupt
>>>> kvmppc_interrupt:
>>> 
>>> Just always call it kvmppc_interrupt_pr and thus share at least that
>>> part of the code :).
>> 
>> But if i don't have HV enabled, we don't compile book3s_hv_rmhandlers.S
>> Hence don't have the kvmppc_interrupt symbol defined.
>
> Ah, because we're always jumping to kvmppc_interrupt. Can we make this
> slightly less magical? How about we always call kvmppc_interrupt_hv
> when CONFIG_KVM_BOOK3S_HV_POSSIBLE and always kvmppc_interrupt_pr when
> CONFIG_KVM_BOOK3S_PR_POSSIBLE and then branch to kvmppc_interrupt_pr
> from kvmppc_interrupt_hv?
>
> IMHO that would make the code flow more obvious.

To make sure I understand you correctly, what you are suggesting is
to update __KVM_HANDLER to call kvmppc_interupt_pr when HV is not
enabled ?

-aneesh