From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [Qemu-devel] [PATCH] qemu: msi irq allocation api Date: Thu, 21 May 2009 13:50:10 +0300 Message-ID: <20090521105010.GC25309@redhat.com> References: <20090520162130.GA22109@redhat.com> <200905211109.09844.paul@codesourcery.com> <4A152B8D.5020006@redhat.com> <200905211134.21184.paul@codesourcery.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: qemu-devel@nongnu.org, Avi Kivity , Carsten Otte , kvm@vger.kernel.org, Rusty Russell , virtualization@lists.linux-foundation.org, Christian Borntraeger To: Paul Brook Return-path: Received: from mx2.redhat.com ([66.187.237.31]:38484 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752339AbZEUKxP (ORCPT ); Thu, 21 May 2009 06:53:15 -0400 Content-Disposition: inline In-Reply-To: <200905211134.21184.paul@codesourcery.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, May 21, 2009 at 11:34:11AM +0100, Paul Brook wrote: > > The PCI bus doesn't need any special support (I think) but something on > > the other end needs to interpret those writes. > > Sure. But there's definitely nothing PCI specific about it. I assumed this > would all be contained within the APIC. Exactly. APIC supplies callbacks to set up/free/mask/unmask MSI interrupts. For kvm, we'll have another implementation that passes these requests on to kernel. > > In any case we need some internal API for this, and qemu_irq looks like > > a good choice. > > What do you expect to be using this API? > > Paul emulated PCI devices such as virtio. Hope to send a patch shortly. -- MST