From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [Qemu-devel] [PATCH] qemu: msi irq allocation api Date: Thu, 21 May 2009 18:11:42 +0300 Message-ID: <4A156F2E.4050802@redhat.com> References: <20090520162130.GA22109@redhat.com> <200905211550.21217.paul@codesourcery.com> <4A156B41.4090608@redhat.com> <200905211601.33164.paul@codesourcery.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, Carsten Otte , kvm@vger.kernel.org, "Michael S. Tsirkin" , Rusty Russell , virtualization@lists.linux-foundation.org, Christian Borntraeger To: Paul Brook Return-path: Received: from mx2.redhat.com ([66.187.237.31]:57905 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752810AbZEUPOd (ORCPT ); Thu, 21 May 2009 11:14:33 -0400 In-Reply-To: <200905211601.33164.paul@codesourcery.com> Sender: kvm-owner@vger.kernel.org List-ID: Paul Brook wrote: >> The fast path is an eventfd so that we don't have to teach all the >> clients about the details of MSI. Userspace programs the MSI details >> into kvm and hands the client an eventfd. All the client has to do is >> bang on the eventfd for the interrupt to be queued. The eventfd >> provides event coalescing and is equally useful from the kernel and >> userspace, and can be used with targets other than kvm. >> > > So presumably if a device triggers an APIC interrupt using a write that isn't > one of the currently configured PCI devices, it all explodes horribly? > I don't follow. Can you elaborate on your scenario? -- error compiling committee.c: too many arguments to function