From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5AACC32771 for ; Mon, 6 Jan 2020 07:24:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B1CA920848 for ; Mon, 6 Jan 2020 07:24:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726696AbgAFHYW (ORCPT ); Mon, 6 Jan 2020 02:24:22 -0500 Received: from mga12.intel.com ([192.55.52.136]:48996 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726488AbgAFHYW (ORCPT ); Mon, 6 Jan 2020 02:24:22 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Jan 2020 23:24:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,401,1571727600"; d="scan'208";a="222761835" Received: from liujing-mobl1.ccr.corp.intel.com (HELO [10.238.130.219]) ([10.238.130.219]) by orsmga003.jf.intel.com with ESMTP; 05 Jan 2020 23:24:20 -0800 Subject: Re: [PATCH v1 2/2] virtio-mmio: add features for virtio-mmio specification version 3 To: "Michael S. Tsirkin" , "Liu, Jiang" Cc: Jason Wang , Zha Bin , linux-kernel@vger.kernel.org, slp@redhat.com, virtio-dev@lists.oasis-open.org, jing2.liu@intel.com, chao.p.peng@intel.com References: <229e689d-10f1-2bfb-c393-14dfa9c78971@redhat.com> <0460F92A-3DF6-4F7A-903B-6434555577CC@linux.alibaba.com> <56703BDA-B7AE-4656-8061-85FD1A130597@linux.alibaba.com> <20200105054142-mutt-send-email-mst@kernel.org> From: "Liu, Jing2" Message-ID: Date: Mon, 6 Jan 2020 15:24:18 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <20200105054142-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/5/2020 6:42 PM, Michael S. Tsirkin wrote: > On Thu, Dec 26, 2019 at 09:16:19PM +0800, Liu, Jiang wrote: >>> 2) The mask and unmask control is missed >>> >>> >>>> but the extension doesn’t support 3) because >>>> we noticed that the Linux virtio subsystem doesn’t really make use of interrupt masking/unmasking. > Linux uses masking/unmasking in order to migrate interrupts between > CPUs. Hi Michael, Thanks for reviewing the patches! When trying to study the mask/unmask use case during migrating irq, it seems being used e.g. 1) migrate irq(s) away from offline cpu 2) irq affinity is changing, while an interrupt comes so it sets SETAFFINITY_PENDING and the lapic (e.g. x86) does the mask and unmask to finish the pending during ack. Is this right? So we should have mask/unmask for each vector. Thanks, Jing