From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MgWzQ-0006GM-D7 for qemu-devel@nongnu.org; Thu, 27 Aug 2009 00:53:36 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MgWzL-0006Cm-Ig for qemu-devel@nongnu.org; Thu, 27 Aug 2009 00:53:35 -0400 Received: from [199.232.76.173] (port=50822 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MgWzL-0006CU-BK for qemu-devel@nongnu.org; Thu, 27 Aug 2009 00:53:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:63555) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MgWzK-0002YY-Qv for qemu-devel@nongnu.org; Thu, 27 Aug 2009 00:53:31 -0400 Message-ID: <4A961161.5030906@redhat.com> Date: Thu, 27 Aug 2009 07:53:53 +0300 From: Avi Kivity 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> <4A95633E.7060703@redhat.com> In-Reply-To: <4A95633E.7060703@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: Gerd Hoffmann Cc: qemu-devel@nongnu.org On 08/26/2009 07:30 PM, Gerd Hoffmann wrote: > On 08/26/09 18:06, Avi Kivity wrote: >> On 08/26/2009 07:03 PM, Gerd Hoffmann wrote: >>> 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). > > Right now we have IRQs 5,10,11 for PCI. Having one more IRQ (so we > have one for each link) would be useful IMHO. eight links + eight > irqs would be even more useful. What needs to be done for that? > > BTW: Seems linux doesn't use IRQ 5 even with lots of PCI devices, > instead it makes them share 10+11 ... We could change the defaults to include 5, but maybe it makes more sense to fix Linux to distribute active PCI IRQs across the resources it has at its disposal. > >> Now I don't think it's worthwhile, as every guest that >> is interesting from a performance point of view has MSI support. > > Not all emulated devices have MSI support though ... They'll be slow regardless. I should be easy to support msi on e1000 though. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.