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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT 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 1258DC3A59B for ; Mon, 2 Sep 2019 04:02:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D714D21744 for ; Mon, 2 Sep 2019 04:02:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726859AbfIBECD (ORCPT ); Mon, 2 Sep 2019 00:02:03 -0400 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:56131 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725681AbfIBECC (ORCPT ); Mon, 2 Sep 2019 00:02:02 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01422;MF=luoben@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0Tb3eY5p_1567396912; Received: from localhost(mailfrom:luoben@linux.alibaba.com fp:SMTPD_---0Tb3eY5p_1567396912) by smtp.aliyun-inc.com(127.0.0.1); Mon, 02 Sep 2019 12:01:55 +0800 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 Subject: [PATCH v6 0/3] genirq/vfio: Introduce irq_update_devid() and optimize VFIO irq ops Date: Mon, 2 Sep 2019 12:01:49 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(-) -- 1.8.3.1