Re: [PATCH 2/5]KVM:x86, apicv: adjust for virtual interrupt delivery

[Avi Kivity <avi@redhat.com>]

On 09/05/2012 08:41 AM, Li, Jiongxi wrote:
> Virtual interrupt delivery avoids KVM to inject vAPIC interrupts
> manually, which is fully taken care of by the hardware. This needs
> some special awareness into existing interrupr injection path:
> 
>   - for pending interrupt, instead of direct injection, we may need
>     update architecture specific indicators before resuming to guest.
> 
>   - A pending interrupt, which is masked by ISR, should be also
>     considered in above update action, since hardware will decide
>     when to inject it at right time. Current has_interrupt and
>     get_interrupt only returns a valid vector from injection p.o.v.
> 
>  
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5194,6 +5194,13 @@ static void inject_pending_event(struct kvm_vcpu *vcpu)
>  			vcpu->arch.nmi_injected = true;
>  			kvm_x86_ops->set_nmi(vcpu);
>  		}
> +	} else if (kvm_apic_vid_enabled(vcpu)) {
> +		if (kvm_cpu_has_interrupt_apic_vid(vcpu) &&
> +		    kvm_x86_ops->interrupt_allowed(vcpu)) {
> +			kvm_queue_interrupt(vcpu,
> +				kvm_cpu_get_interrupt_apic_vid(vcpu), false);
> +			kvm_x86_ops->set_irq(vcpu);
> +		}

It may be simpler to change kvm_cpu_{has,get}_interrupt to ignore the
apic if virtual interrupt delivery is enabled.

> @@ -5293,16 +5300,27 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
>  	}
>  
>  	if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
> +		/* update archtecture specific hints for APIC virtual interrupt delivery */
> +		if (kvm_apic_vid_enabled(vcpu))
> +			kvm_x86_ops->update_irq(vcpu);
> +

Not defined.

>  		inject_pending_event(vcpu);
>  
>  		/* enable NMI/IRQ window open exits if needed */
>  		if (vcpu->arch.nmi_pending)
>  			kvm_x86_ops->enable_nmi_window(vcpu);
> -		else if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
> +		else if (kvm_apic_vid_enabled(vcpu)) {
> +			if (kvm_cpu_has_interrupt_apic_vid(vcpu))
> +				kvm_x86_ops->enable_irq_window(vcpu);
> +		} else if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
>  			kvm_x86_ops->enable_irq_window(vcpu);
>  
>  		if (kvm_lapic_enabled(vcpu)) {
> -			update_cr8_intercept(vcpu);
> +			/* no need for tpr_threshold update if APIC virtual
> +			 * interrupt delivery is enabled
> +			 */
> +			if (!kvm_apic_vid_enabled(vcpu))
> +				update_cr8_intercept(vcpu);

Perhaps the arch function should do the ignoring.

>  			kvm_lapic_sync_to_vapic(vcpu);
>  		}
>  	}
> 


-- 
error compiling committee.c: too many arguments to function