From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yang, Sheng" Subject: Re: Remaining passthrough/VT-d tasks list Date: Sun, 28 Sep 2008 14:09:41 +0800 Message-ID: <200809281409.42301.sheng.yang@intel.com> References: <0122C7C995D32147B66BF4F440D3016301C49E61@pdsmsx415.ccr.corp.intel.com> <200809241743.02566.sheng.yang@intel.com> <48DA0D9C.5060100@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" 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: Avi Kivity Return-path: Received: from mga09.intel.com ([134.134.136.24]:11723 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750925AbYI1GIw (ORCPT ); Sun, 28 Sep 2008 02:08:52 -0400 In-Reply-To: <48DA0D9C.5060100@redhat.com> Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: On Wednesday 24 September 2008 17:51:24 Avi Kivity wrote: > 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. > I am working on this now. -- regards Yang, Sheng