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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 25092C4363A for ; Wed, 21 Oct 2020 09:31:32 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 640FE21D6C for ; Wed, 21 Oct 2020 09:31:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 640FE21D6C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:60486 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kVASt-0001R3-BO for qemu-devel@archiver.kernel.org; Wed, 21 Oct 2020 05:31:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60054) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kVARv-0000ef-Bj for qemu-devel@nongnu.org; Wed, 21 Oct 2020 05:30:27 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:5713 helo=huawei.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kVARs-000565-An for qemu-devel@nongnu.org; Wed, 21 Oct 2020 05:30:27 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 9267EDCBFFAFB47D868B; Wed, 21 Oct 2020 17:30:16 +0800 (CST) Received: from [10.174.185.179] (10.174.185.179) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.487.0; Wed, 21 Oct 2020 17:30:06 +0800 Subject: Re: [PATCH v26 03/17] vfio: Add save and load functions for VFIO PCI devices To: Alex Williamson , Kirti Wankhede References: <1600817059-26721-1-git-send-email-kwankhede@nvidia.com> <1600817059-26721-4-git-send-email-kwankhede@nvidia.com> <20200924164905.1a2f1384@x1.home> From: Zenghui Yu Message-ID: Date: Wed, 21 Oct 2020 17:30:04 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200924164905.1a2f1384@x1.home> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.185.179] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.191; envelope-from=yuzenghui@huawei.com; helo=huawei.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/21 03:34:19 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: cohuck@redhat.com, cjia@nvidia.com, aik@ozlabs.ru, Zhengxiao.zx@Alibaba-inc.com, shuangtai.tst@alibaba-inc.com, qemu-devel@nongnu.org, peterx@redhat.com, eauger@redhat.com, yi.l.liu@intel.com, eskultet@redhat.com, ziye.yang@intel.com, armbru@redhat.com, mlevitsk@redhat.com, pasic@linux.ibm.com, felipe@nutanix.com, wanghaibin.wang@huawei.com, Ken.Xue@amd.com, kevin.tian@intel.com, yan.y.zhao@intel.com, dgilbert@redhat.com, changpeng.liu@intel.com, quintela@redhat.com, lushenming@huawei.com, zhi.a.wang@intel.com, jonathan.davies@nutanix.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2020/9/25 6:49, Alex Williamson wrote: >> + } else if (interrupt_type == VFIO_INT_MSIX) { >> + uint16_t offset; >> + >> + msix_load(pdev, f); >> + offset = pci_default_read_config(pdev, >> + pdev->msix_cap + PCI_MSIX_FLAGS + 1, 2); >> + /* load enable bit and maskall bit */ >> + vfio_pci_write_config(pdev, pdev->msix_cap + PCI_MSIX_FLAGS + 1, >> + offset, 2); It isn't clear that what purpose this load operation serves. The config space has already been restored and we'll see that MSI-X _was_ and _is_ enabled (or disabled). vfio_msix_enable() will therefore not be invoked and no vectors would actually be enabled... Not sure if I had missed something. >> + } >> + return 0; > > It seems this could be simplified down to: > > if (msi_enabled(pdev)) { > vfio_msi_enable(vdev); > } else if (msix_enabled(pdev)) { > msix_load(pdev, f); > vfio_msix_enable(vdev); > } And it seems that this has fixed something :-) Thanks, Zenghui