Re: [PATCH v5 4/5] KVM: VMX: Add the algorithm of deliver posted interrupt

[Marcelo Tosatti <mtosatti@redhat.com>]

On Fri, Mar 08, 2013 at 09:23:20AM +0800, Yang Zhang wrote:
> From: Yang Zhang <yang.z.zhang@Intel.com>
> 
> Only deliver the posted interrupt when target vcpu is running
> and there is no previous interrupt pending in pir.
> 
> Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>

> +static bool vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector)
> +{
> +	struct vcpu_vmx *vmx = to_vmx(vcpu);
> +
> +	if (!vmx_vm_has_apicv(vcpu->kvm))
> +		return false;
> +
> +	if (pi_test_and_set_pir(vector, &vmx->pi_desc))
> +		return true;
> +
> +	kvm_make_request(KVM_REQ_EVENT, vcpu);
> +	if ((vcpu->mode == IN_GUEST_MODE)) {
> +		if (!pi_test_and_set_on(&vmx->pi_desc))
> +			apic->send_IPI_mask(get_cpu_mask(vcpu->cpu),
> +					POSTED_INTR_VECTOR);
> +	} else
> +		kvm_vcpu_kick(vcpu);
> +
> +	return true;
> +}

Meaning of return value is unclear.

> +
> +static bool vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu, bool sync)
> +{
> +	struct vcpu_vmx *vmx = to_vmx(vcpu);
> +
> +	if (!vmx_vm_has_apicv(vcpu->kvm))
> +		return false;
> +
> +	if (bitmap_empty((unsigned long *)vmx->pi_desc.pir, 256))
> +		return false;
> +
> +	if (sync)
> +		kvm_apic_update_irr(vcpu, vmx->pi_desc.pir);
> +	return true;
> +}

Please split in two kvm_x86_ops functions: one to query whether PIR is empty the other 
to perform the sync.

Perhaps "->hwapic_has_interrupt" is a good name.