From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: Mask bit support's API Date: Tue, 23 Nov 2010 17:24:44 +0200 Message-ID: <20101123152444.GC25606@redhat.com> References: <201011231409.52666.sheng.yang@intel.com> <201011231630.36895.sheng.yang@intel.com> <4CEBB7E5.5030601@redhat.com> <201011232157.05130.sheng.yang@intel.com> <4CEBCA5C.8040504@redhat.com> <20101123151119.GB31722@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , "Yang, Sheng" , Marcelo Tosatti , "kvm@vger.kernel.org" To: "Michael S. Tsirkin" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:62450 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755296Ab0KWPYr (ORCPT ); Tue, 23 Nov 2010 10:24:47 -0500 Content-Disposition: inline In-Reply-To: <20101123151119.GB31722@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Nov 23, 2010 at 05:11:19PM +0200, Michael S. Tsirkin wrote: > On Tue, Nov 23, 2010 at 04:06:20PM +0200, Avi Kivity wrote: > > >> > > >> So instead of > > >> > > >> - guest reads/writes msix > > >> - kvm filters mmio, implements some, passes others to userspace > > >> > > >> we have > > >> > > >> - guest reads/writes msix > > >> - kvm implements all > > >> - some writes generate an additional notification to userspace > > > > > >I suppose we don't need to generate notification to userspace? Because every > > >read/write is handled by kernel, and userspace just need interface to kernel to > > >get/set the entry - and well, does userspace need to do it when kernel can handle > > >all of them? Maybe not... > > > > We could have the kernel handle addr/data writes by setting up an > > internal interrupt routing. A disadvantage is that more work is > > needed if we emulator interrupt remapping in qemu. > > As an alternative, interrupt remapping will need some API rework, right? > Existing APIs only pass address/data for msi. > IIRC interrupt remapping works with address/data to. It just interpret it differently from apic. -- Gleb.