linux-kernel - Re: [PATCH] KVM: X86: Add 'else' to unify fastop and execute call path

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Date:   Tue, 21 Jan 2020 20:42:56 -0800
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     linmiaohe <linmiaohe@...wei.com>
Cc:     pbonzini@...hat.com, rkrcmar@...hat.com, vkuznets@...hat.com,
        wanpengli@...cent.com, jmattson@...gle.com, joro@...tes.org,
        tglx@...utronix.de, mingo@...hat.com, bp@...en8.de, hpa@...or.com,
        kvm@...r.kernel.org, linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH] KVM: X86: Add 'else' to unify fastop and execute call
 path

On Wed, Jan 22, 2020 at 11:21:44AM +0800, linmiaohe wrote:
> From: Miaohe Lin <linmiaohe@...wei.com>
> 
> It also helps eliminate some duplicated code.
> 
> Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
> ---

Reviewed-by: Sean Christopherson <sean.j.christopherson@...el.com>

>  arch/x86/kvm/emulate.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> index c7a0da45f60a..0accce94f660 100644
> --- a/arch/x86/kvm/emulate.c
> +++ b/arch/x86/kvm/emulate.c
> @@ -5683,11 +5683,9 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
>  		if (ctxt->d & Fastop) {
>  			void (*fop)(struct fastop *) = (void *)ctxt->execute;

The brackets can also be removed with a bit more cleanup, e.g. using a
typedef to handling casting ctxt->execute.  I'll send a patch that can be
applied on top and/or squashed with this one.

>  			rc = fastop(ctxt, fop);
> -			if (rc != X86EMUL_CONTINUE)
> -				goto done;
> -			goto writeback;
> +		} else {
> +			rc = ctxt->execute(ctxt);
>  		}
> -		rc = ctxt->execute(ctxt);
>  		if (rc != X86EMUL_CONTINUE)
>  			goto done;
>  		goto writeback;
> -- 
> 2.19.1
>