# Re: \[PATCH 2/2\] KVM: not link irqfd with a fake IRQ bypass producer

- From: Jason Wang \<hidden\>
- Date: 2020-10-20 06:32:29 
- List: netdev
- Page: https://ratatoskr.run/netdev/2020/10/6144519
- Thread: https://ratatoskr.run/kvm/2020/10/6143546/t.md

```text

On 2020/10/19 下午5:06, Zhenzhong Duan wrote:
> In case failure to setup Post interrupt for an IRQ, it make no sense
> to assign irqfd->producer to the producer.
>
> This change makes code more robust.


It's better to describe what issue we will get without this patch.

Thanks


>
> Signed-off-by: Zhenzhong Duan <redacted>
> ---
>   arch/x86/kvm/x86.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index ce856e0..277e961 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -10683,13 +10683,14 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
>   		container_of(cons, struct kvm_kernel_irqfd, consumer);
>   	int ret;
>   
> -	irqfd->producer = prod;
>   	kvm_arch_start_assignment(irqfd->kvm);
>   	ret = kvm_x86_ops.update_pi_irte(irqfd->kvm,
>   					 prod->irq, irqfd->gsi, 1);
>   
>   	if (ret)
>   		kvm_arch_end_assignment(irqfd->kvm);
> +	else
> +		irqfd->producer = prod;
>   
>   	return ret;
>   }

```