From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sheng Yang Subject: Re: [PATCH 1/3] KVM: Add MSI_ACTION flag for assigned irq Date: Tue, 30 Dec 2008 18:34:44 +0800 Message-ID: <200812301834.44318.sheng@linux.intel.com> References: <1230616173-17723-1-git-send-email-sheng@linux.intel.com> <200812301826.13471.sheng@linux.intel.com> <4959F874.4090403@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: Avi Kivity To: kvm@vger.kernel.org Return-path: Received: from mga06.intel.com ([134.134.136.21]:11548 "EHLO orsmga101.jf.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751677AbYL3Ker (ORCPT ); Tue, 30 Dec 2008 05:34:47 -0500 In-Reply-To: <4959F874.4090403@redhat.com> Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: On Tuesday 30 December 2008 18:31:16 Avi Kivity wrote: > Sheng Yang wrote: > > On Tuesday 30 December 2008 18:19:29 Avi Kivity wrote: > >> Sheng Yang wrote: > >>> For MSI disable feature later. > >>> > >>> Notice I changed ABI here, but due to no userspace patch, I think it's > >>> OK. > >> > >> It's not okay, since eventually we will have userspace and it will have > >> to work with older kernels as well. > >> > >> No released kernel has KVM_DEV_IRQ_ASSIGN_ENABLE_MSI, so it's fine, > >> provided I fold this into the 2.6.29 submission. However, why do this > >> at all? It can only cause confusion. > > > > If we have ENABLE_MSI, and DISABLE, and ENABLE_MSIX, and DISABLE, and > > MASK_MSIX, and UNMASK, every two action are in pairs but we have to use > > twice bits to store them. So I'd like to use MSI_ACTION approach... > > Well, it you have flags without ENABLE_MSI, doesn't it imply DISABLE_MSI? > > The structure contains the state we want to reach, not a command we wish > the kernel to perform. Yes, that's what I want. But check more than one flags(for MSI-X) to determine where to go is not that clear. So I add a flag here to indicate the operation type which I think is a little more clear. -- regards Yang, Sheng