From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Remaining passthrough/VT-d tasks list Date: Wed, 24 Sep 2008 12:51:24 +0300 Message-ID: <48DA0D9C.5060100@redhat.com> References: <0122C7C995D32147B66BF4F440D3016301C49E61@pdsmsx415.ccr.corp.intel.com> <200809241708.31835.sheng.yang@intel.com> <48DA06ED.9090605@redhat.com> <200809241743.02566.sheng.yang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Han, Weidong" , "kvm@vger.kernel.org" , Amit Shah , "benami@il.ibm.com" , "muli@il.ibm.com" , "Kay, Allen M" , "Zhang, Xiantao" To: "Yang, Sheng" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:40675 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751733AbYIXJxm (ORCPT ); Wed, 24 Sep 2008 05:53:42 -0400 In-Reply-To: <200809241743.02566.sheng.yang@intel.com> Sender: kvm-owner@vger.kernel.org List-ID: Yang, Sheng wrote: >> 2. shared guest pci interrupts >> >> That's a correctness issue. No matter how many interrupts we have, we >> may have sharing issues. Of course with only three the issue is very >> pressing since we will get sharing with just a few devices. Currently >> if two assigned devices share a guest interrupts, or if an emulated >> device shares an interrupt with an assigned device, things will break. >> >> They need to be fixed independently. >> > > About the second issue, I don't understand how it would break... Would you > please give more details on this? It's a QEmu bug or IOAPIC bug? > It's a kernel bug. Both the device assignment code and KVM_SET_IRQ ioctl() call kvm_set_irq(), so the last one wins. We need logical-OR mixing between the various sources. Just like pci_set_irq() in qemu, only for the kernel. Userspace is one source, each assigned device irq is a separate source. -- error compiling committee.c: too many arguments to function