From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: Mask bit support's API Date: Tue, 23 Nov 2010 17:11:19 +0200 Message-ID: <20101123151119.GB31722@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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Yang, Sheng" , Marcelo Tosatti , "kvm@vger.kernel.org" To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:23080 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753414Ab0KWPLd (ORCPT ); Tue, 23 Nov 2010 10:11:33 -0500 Content-Disposition: inline In-Reply-To: <4CEBCA5C.8040504@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: 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. -- MST