From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yang, Sheng" Subject: Re: Remaining passthrough/VT-d tasks list Date: Wed, 24 Sep 2008 17:08:31 +0800 Message-ID: <200809241708.31835.sheng.yang@intel.com> References: <0122C7C995D32147B66BF4F440D3016301C49E61@pdsmsx415.ccr.corp.intel.com> <200809241642.54667.sheng.yang@intel.com> <48D9FFFB.5040505@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 mga01.intel.com ([192.55.52.88]:22851 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752342AbYIXJH4 (ORCPT ); Wed, 24 Sep 2008 05:07:56 -0400 In-Reply-To: <48D9FFFB.5040505@redhat.com> Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: On Wednesday 24 September 2008 16:53:15 Avi Kivity wrote: > Yang, Sheng wrote: > >> Shared guest interrupts is a prerequisite for merging into mainline. > >> Without this, device assignment is useless in anything but a benchmark > >> scenario. I won't push device assignment for 2.6.28 without it. > >> > >> Shared host interrupts are a different matter; which one did you mean? > > > > Got confused... > > > > I think we are talking about share host interrupts, that is pre-assigned > > device shared IRQ with other devices. > > > > Why share guest interrupts is a prerequisite... > > We only have three pci interrupts at this point (though this could be > easily extended); if you start the guest with a non-trivial number of > devices, you will have shared guest interrupts. > > (of course, when I pointed this out during review, people said it could > be done later, then forgot all about it) > ...... I think it's a performance issue, not break it? How about do it like Xen side? Try best to avoid the share, extended the pci interrupts, improve hash algorithm. Is there anything else we can do? -- regards Yang, Sheng