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

From: Paolo Bonzini
Date: Mon Oct 21 2019 - 04:59:10 EST


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@xxxxxxxxxx>
> ---
> 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;
> }
>