From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58262) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apaVV-00033U-IS for qemu-devel@nongnu.org; Mon, 11 Apr 2016 07:59:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1apaVR-0000XN-Im for qemu-devel@nongnu.org; Mon, 11 Apr 2016 07:59:53 -0400 Received: from [59.151.112.132] (port=23587 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apaVR-0000Wm-64 for qemu-devel@nongnu.org; Mon, 11 Apr 2016 07:59:49 -0400 References: <1459855602-16727-1-git-send-email-caoj.fnst@cn.fujitsu.com> <1459855602-16727-6-git-send-email-caoj.fnst@cn.fujitsu.com> <87pou0sd4u.fsf@dusky.pond.sub.org> <5708F33B.2040000@cn.fujitsu.com> <570A0CB7.1040509@redhat.com> <570A1F1B.90502@cn.fujitsu.com> <570B75BA.3050800@redhat.com> From: Cao jin Message-ID: <570B9251.5040403@cn.fujitsu.com> Date: Mon, 11 Apr 2016 20:02:25 +0800 MIME-Version: 1.0 In-Reply-To: <570B75BA.3050800@redhat.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 5/5] Add param Error ** for msi_init() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcel Apfelbaum , Markus Armbruster Cc: qemu-devel@nongnu.org, mst@redhat.com, jasowang@redhat.com, alex.williamson@redhat.com, hare@suse.de, dmitry@daynix.com, pbonzini@redhat.com, jsnow@redhat.com, kraxel@redhat.com On 04/11/2016 06:00 PM, Marcel Apfelbaum wrote: > >> 2). If user doesn`t order msi on(so device have msi on by default), >> when msi_init returns -ENOTSUP, I am ok with Markus`s suggestion: >> *caller should silently switch to the non-MSI variant* >> >> But now the condition is, qemu can`t distinguish whether user ordered >> msi or not, so for the condition 2) above, my suggestion is the same >> as 1) >> > > If we can't distinguish between the cases, 2 would not be user-friendly. > Once it would be possible to differentiate we could go for 2. > Hi, How to differentiate? Do you mean: let these msi(msix) property default to 'off'? It seem most device have it on, a few have it off. > > Thanks, > Marcel > -- Yours Sincerely, Cao jin