From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Mgr4L-0003y5-UB for qemu-devel@nongnu.org; Thu, 27 Aug 2009 22:20:03 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Mgr4D-0003qf-63 for qemu-devel@nongnu.org; Thu, 27 Aug 2009 22:19:57 -0400 Received: from [199.232.76.173] (port=34072 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Mgr4C-0003qb-Ow for qemu-devel@nongnu.org; Thu, 27 Aug 2009 22:19:53 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:60272) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Mgr4B-0004u1-RB for qemu-devel@nongnu.org; Thu, 27 Aug 2009 22:19:52 -0400 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e31.co.us.ibm.com (8.14.3/8.13.1) with ESMTP id n7S2E8mk014823 for ; Thu, 27 Aug 2009 20:14:08 -0600 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n7S2Jmob263612 for ; Thu, 27 Aug 2009 20:19:48 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n7S2JlOO016973 for ; Thu, 27 Aug 2009 20:19:47 -0600 Message-ID: <4A973EF1.10707@us.ibm.com> Date: Thu, 27 Aug 2009 22:20:33 -0400 From: Beth Kon MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 2/2] Route IOAPIC interrupts via ISA bus References: <1249836296-13288-1-git-send-email-avi@redhat.com> <1249836296-13288-3-git-send-email-avi@redhat.com> <4A955CB4.4080205@redhat.com> <4A955D6A.9060804@redhat.com> In-Reply-To: <4A955D6A.9060804@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: Gerd Hoffmann , qemu-devel@nongnu.org Avi Kivity wrote: > On 08/26/2009 07:03 PM, Gerd Hoffmann wrote: >> On 08/09/09 18:44, Avi Kivity wrote: >>> Instead of calling the IOAPIC from the PIC, raise IOAPIC irqs via >>> the ISA bus. >>> As a side effect, IOAPIC lines 16-23 are enabled. >> >> Now we probably need some acpi magic to tell the guest OS that there >> are a few more IRQ lines? >> > > I wanted to route the PCI IRQs to those lines (and have eight links > instead of four). Now I don't think it's worthwhile, as every guest > that is interesting from a performance point of view has MSI support. > > So I think we should just leave these lines as is, terminated with a > 4.7K resistor to avoid picking up noise. > I was thinking of the HPET advertising one or more of these new ioapic interrupts so that it could support non-legacy operation. It can't at the moment because there are no interrupt lines available. I haven't looked into the details of what would remain to be done to make this happen, but does it sound reasonable? Sounds like at a minimum acpi needs some work.