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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 4327FC3A5A2 for ; Tue, 10 Sep 2019 06:30:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D3BF2089F for ; Tue, 10 Sep 2019 06:30:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393421AbfIJGa1 (ORCPT ); Tue, 10 Sep 2019 02:30:27 -0400 Received: from out30-54.freemail.mail.aliyun.com ([115.124.30.54]:58251 "EHLO out30-54.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729634AbfIJGa0 (ORCPT ); Tue, 10 Sep 2019 02:30:26 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=luoben@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0Tbz28j6_1568097016; Received: from bn0418deMacBook-Pro.local(mailfrom:luoben@linux.alibaba.com fp:SMTPD_---0Tbz28j6_1568097016) by smtp.aliyun-inc.com(127.0.0.1); Tue, 10 Sep 2019 14:30:17 +0800 Subject: Re: [PATCH v6 0/3] genirq/vfio: Introduce irq_update_devid() and optimize VFIO irq ops From: Ben Luo To: tglx@linutronix.de, alex.williamson@redhat.com Cc: linux-kernel@vger.kernel.org, tao.ma@linux.alibaba.com, gerry@linux.alibaba.com, nanhai.zou@linux.alibaba.com References: Message-ID: Date: Tue, 10 Sep 2019 14:30:16 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A friendly reminder. Thanks,     Ben 在 2019/9/2 下午12:01, Ben Luo 写道: > Currently, VFIO takes a free-then-request-irq way to do interrupt > affinity setting and masking/unmasking for a VM with device passthru > via VFIO. Sometimes it only changes the cookie data of irqaction or even > changes nothing. The free-then-request-irq not only adds more latency, > but also increases the risk of losing interrupt, which may lead to a > VM hang forever in waiting for IO completion > > This patchset solved the issue by: > Patch 2 introduces irq_update_devid() to only update dev_id of irqaction > Patch 3 make use of this function and optimize irq operations in VFIO > > changes from v5: > - Patch 3: remove an error log to avoid potential DDoS attacking > _ Patch 3: fix typo in comment > > changes from v4: > - Patch 3: follow the previous behavior to disable interrupt on error path > - Patch 3: do irqbypass registration before update or free the interrupt > - Patch 3: add more comments > > changes from v3: > - Patch 2: rename the new function to irq_update_devid() > - Patch 2: use disbale_irq() to avoid a twist for threaded interrupt > - ALL: amend commit messages and code comments > > changes from v2: > - reformat to avoid quoted string split across lines and etc. > > changes from v1: > - add Patch 1 to enhance error recovery etc. in free irq per tglx's comments > - enhance error recovery code and debugging info in irq_update_devid > - use __must_check in external referencing of this function > - use EXPORT_SYMBOL_GPL for irq_update_devid > - reformat code of patch 3 for better readability > > Ben Luo (3): > genirq: enhance error recovery code in free irq > genirq: introduce irq_update_devid() > vfio/pci: make use of irq_update_devid() and optimize irq ops > > drivers/vfio/pci/vfio_pci_intrs.c | 118 ++++++++++++++++++++++++++------------ > include/linux/interrupt.h | 3 + > kernel/irq/manage.c | 105 +++++++++++++++++++++++++++++---- > 3 files changed, 177 insertions(+), 49 deletions(-) >