[PATCH v2] KVM: remove redundant code in kvm_arch_vm_ioctl

[PATCH v2] KVM: remove redundant code in kvm_arch_vm_ioctl

[Miaohe Lin]

If we reach here with r = 0, we will reassign r = 0
unnecesarry, then do the label set_irqchip_out work.
If we reach here with r != 0, then we will do the label
work directly. So this if statement and r = 0 assignment
is redundant. We remove them and therefore we can get rid
of odd set_irqchip_out lable further pointed out by tglx.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 arch/x86/kvm/x86.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 661e2bf38526..cd4ca8c2f7de 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4913,13 +4913,8 @@ long kvm_arch_vm_ioctl(struct file *filp,
 		}
 
 		r = -ENXIO;
-		if (!irqchip_kernel(kvm))
-			goto set_irqchip_out;
-		r = kvm_vm_ioctl_set_irqchip(kvm, chip);
-		if (r)
-			goto set_irqchip_out;
-		r = 0;
-	set_irqchip_out:
+		if (irqchip_kernel(kvm))
+			r = kvm_vm_ioctl_set_irqchip(kvm, chip);
 		kfree(chip);
 		break;
 	}
-- 
2.19.1

Re: [PATCH v2] KVM: remove redundant code in kvm_arch_vm_ioctl

[Paolo Bonzini]

On 21/10/19 10:52, Miaohe Lin wrote:
> If we reach here with r = 0, we will reassign r = 0
> unnecesarry, then do the label set_irqchip_out work.
> If we reach here with r != 0, then we will do the label
> work directly. So this if statement and r = 0 assignment
> is redundant. We remove them and therefore we can get rid
> of odd set_irqchip_out lable further pointed out by tglx.

While Thomas's suggestion certainly makes sense, I prefer to keep the
get and set cases similar to each other, so I queued your v1 patch.
Thanks for making the KVM code cleaner!

Paolo

> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> ---
>  arch/x86/kvm/x86.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 661e2bf38526..cd4ca8c2f7de 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -4913,13 +4913,8 @@ long kvm_arch_vm_ioctl(struct file *filp,
>  		}
>  
>  		r = -ENXIO;
> -		if (!irqchip_kernel(kvm))
> -			goto set_irqchip_out;
> -		r = kvm_vm_ioctl_set_irqchip(kvm, chip);
> -		if (r)
> -			goto set_irqchip_out;
> -		r = 0;
> -	set_irqchip_out:
> +		if (irqchip_kernel(kvm))
> +			r = kvm_vm_ioctl_set_irqchip(kvm, chip);
>  		kfree(chip);
>  		break;
>  	}
>