Re: [PATCH v2 2/2] KVM: x86: Add lowest-priority support for vt-d posted-interrupts

["Radim Krčmář" <rkrcmar@redhat.com>]

2015-12-16 09:37+0800, Feng Wu:
> Use vector-hashing to deliver lowest-priority interrupts for
> VT-d posted-interrupts.
> 
> Signed-off-by: Feng Wu <feng.wu@intel.com>
> ---
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> @@ -10702,8 +10702,16 @@ static int vmx_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
>  		 */
>  
>  		kvm_set_msi_irq(e, &irq);
> -		if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu))
> -			continue;
> +
> +		if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu)) {
> +			if (!kvm_vector_hashing_enabled() ||
> +					irq.delivery_mode != APIC_DM_LOWEST)

Hm, wouldn't it actually be easier to extend kvm_intr_is_single_vcpu()
with vector hashing? :)

> +				continue;
> +
> +			vcpu = kvm_intr_vector_hashing_dest(kvm, &irq);
> +			if (!vcpu)
> +				continue;
> +		}