From mboxrd@z Thu Jan 1 00:00:00 1970 From: Muli Ben-Yehuda Subject: Re: [PATCH 3/6] qemu: piix: Introduce functions to get pin number from irq and vice versa Date: Tue, 28 Oct 2008 18:45:21 +0200 Message-ID: <20081028164521.GH6737@il.ibm.com> References: <1224861988-22781-1-git-send-email-amit.shah@redhat.com> <1224861988-22781-2-git-send-email-amit.shah@redhat.com> <1224861988-22781-3-git-send-email-amit.shah@redhat.com> <1224861988-22781-4-git-send-email-amit.shah@redhat.com> <4904712C.1080307@redhat.com> <20081028101252.GG7102@il.ibm.com> <4906ED8F.3040608@redhat.com> <20081028154458.GC6737@il.ibm.com> <49073C0F.3050805@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Amit Shah , kvm@vger.kernel.org, anthony@codemonkey.ws, weidong.han@intel.com, allen.m.kay@intel.com, Ben-Ami Yassour1 To: Avi Kivity Return-path: Received: from mtagate4.uk.ibm.com ([195.212.29.137]:37640 "EHLO mtagate4.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752396AbYJ1QqL (ORCPT ); Tue, 28 Oct 2008 12:46:11 -0400 Received: from d06nrmr1407.portsmouth.uk.ibm.com (d06nrmr1407.portsmouth.uk.ibm.com [9.149.38.185]) by mtagate4.uk.ibm.com (8.13.8/8.13.8) with ESMTP id m9SGk5JZ256528 for ; Tue, 28 Oct 2008 16:46:05 GMT Received: from d06av04.portsmouth.uk.ibm.com (d06av04.portsmouth.uk.ibm.com [9.149.37.216]) by d06nrmr1407.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id m9SGk5wU4174002 for ; Tue, 28 Oct 2008 16:46:05 GMT Received: from d06av04.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av04.portsmouth.uk.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m9SGk4vf004913 for ; Tue, 28 Oct 2008 16:46:05 GMT Content-Disposition: inline In-Reply-To: <49073C0F.3050805@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Oct 28, 2008 at 06:21:35PM +0200, Avi Kivity wrote: > Muli Ben-Yehuda wrote: > > >>> Well, what is this needed for in the first place? >>> >> >> This specific function is not used. I assume Amit added it for >> completeness with piix_get_irq. piix_get_irq, as far as I can tell, is >> used in only one place (when the guest updates a device's >> configuration space interrupt register) to go from interrupt pin >> (intx) to guest IRQ line. >> > > In that case, a solution suggests itself... Yes, of course! I don't know how I missed it! Err... What is it? Seriously, I removed piix3_get_pin as soon as I noticed it wasn't actually used, but I am not convinced that there are no aliasing issues remaining with piix_get_irq---most likely because I do not understand PCI interrupt routing to any sufficient degree. Do you see problems remaining with pixx_get_irq? Cheers, Muli -- The First Workshop on I/O Virtualization (WIOV '08) Dec 2008, San Diego, CA, http://www.usenix.org/wiov08/ <-> SYSTOR 2009---The Israeli Experimental Systems Conference http://www.haifa.il.ibm.com/conferences/systor2009/