Re: [RFC PATCH 3/4] KVM: x86: Add EOI exit bitmap inference

[Paolo Bonzini <pbonzini@redhat.com>]

On 13/05/2015 03:47, Steve Rutherford wrote:
> @@ -205,6 +205,8 @@ int kvm_set_irq_routing(struct kvm *kvm,
>  
>  	synchronize_srcu_expedited(&kvm->irq_srcu);
>  
> +	kvm_vcpu_request_scan_userspace_ioapic(kvm);
> +
>  	new = old;
>  	r = 0;
>  

This can be done before synchronize_srcu_expedited, so that changes
ripple to the VCPUs faster.

> +void kvm_vcpu_request_scan_userspace_ioapic(struct kvm *kvm)
> +{
> +	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
> +
> +	if (ioapic)
> +		return;
> +	if (!lapic_in_kernel(kvm))
> +		return;
> +	kvm_make_scan_ioapic_request(kvm);
> +}

This is okay for use in kvm_set_irq_routing (perhaps renamed to
kvm_arch_irq_routing_update), but when it is used here:

>  	if (!irqchip_split(kvm))
>  		kvm_vcpu_request_scan_ioapic(kvm);
> +	else
> +		kvm_vcpu_request_scan_userspace_ioapic(kvm);

... you can simply do this:

- 	if (!irqchip_split(kvm))
-		kvm_vcpu_request_scan_ioapic(kvm);
+	kvm_make_scan_ioapic_request(kvm);

Paolo