RE: [v4 08/16] KVM: kvm-vfio: User API for IRQ forwarding

Wu, Feng
2015-06-29T13:01:45Z

> -----Original Message-----
> From: Joerg Roedel [mailto:joro@8bytes.org]
> Sent: Monday, June 29, 2015 5:23 PM
> To: Wu, Feng
> Cc: Alex Williamson; Eric Auger; Avi Kivity; kvm@vger.kernel.org;
> linux-kernel@vger.kernel.org; pbonzini@redhat.com; mtosatti@redhat.com
> Subject: Re: [v4 08/16] KVM: kvm-vfio: User API for IRQ forwarding
>
> On Mon, Jun 29, 2015 at 09:14:54AM +0000, Wu, Feng wrote:
> > Do you mean updating the hardware IRTEs for all the entries in the irq
> > routing table, no matter whether it is the updated one?
>
> Right, that's what I mean. It seems wrong to me to work around the API
> interface by creating a diff between the old and the new routing table.

Yes the original usage model here doesn't care about the diff between
the old and new, it is a little intrusive to add the comparison code here.

> It is much simpler (and easier to maintain) to just update the IRTE
> and PI structures for all IRQs in the routing table, especially since
> this is not a hot-path.

Agree.

Thanks,
Feng

>
>
> Joerg