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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 66EC5C6FD1C for ; Tue, 14 Mar 2023 09:42:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230447AbjCNJmO (ORCPT ); Tue, 14 Mar 2023 05:42:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229958AbjCNJmK (ORCPT ); Tue, 14 Mar 2023 05:42:10 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1039693E25 for ; Tue, 14 Mar 2023 02:42:07 -0700 (PDT) Received: from kwepemm600005.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4PbT7g0DdDzKmcx; Tue, 14 Mar 2023 17:41:51 +0800 (CST) Received: from [10.67.103.158] (10.67.103.158) by kwepemm600005.china.huawei.com (7.193.23.191) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Tue, 14 Mar 2023 17:42:04 +0800 Subject: Re: [PATCH v8 1/5] vfio/migration: Add debugfs to live migration driver To: Alex Williamson CC: , , , , , References: <20230217084831.35783-1-liulongfang@huawei.com> <20230217084831.35783-2-liulongfang@huawei.com> <20230310164007.301adce8.alex.williamson@redhat.com> From: liulongfang Message-ID: <34da84f8-5b3d-3195-c6fd-5c40e0205246@huawei.com> Date: Tue, 14 Mar 2023 17:42:03 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20230310164007.301adce8.alex.williamson@redhat.com> Content-Type: text/plain; charset="gbk" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.103.158] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm600005.china.huawei.com (7.193.23.191) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/3/11 7:40, Alex Williamson wrote: > On Fri, 17 Feb 2023 16:48:27 +0800 > Longfang Liu wrote: > >> There are multiple devices, software and operational steps involved >> in the process of live migration. An error occurred on any node may >> cause the live migration operation to fail. >> This complex process makes it very difficult to locate and analyze >> the cause when the function fails. >> >> In order to quickly locate the cause of the problem when the >> live migration fails, I added a set of debugfs to the vfio >> live migration driver. >> +-------------------------------------------+ >> | | >> | | >> | QEMU | >> | | >> | | >> +---+----------------------------+----------+ >> | ^ | ^ >> | | | | >> +--------+ | | | | >> | vfio | v | v | >> +--------+ +---------+--+ +---------+--+ >> ^ |src vfio_dev| |dst vfio_dev| >> | +--+---------+ +--+---------+ >> | | ^ | ^ >> | | | | | >> | v | | | >> | +-----------+ +-----------+----+ | | >> +--+file_x+<----+---+migration_attr | | | >> | +-----------+ | +----------------+ | | >> | +---+migration_data | | | >> | | +----------------+ | | >> | +---+migration_debug | | | >> | | +----------------+ | | >> | | +----------------+ | | >> | +---+migration_state | | | >> | +----------------+ | | >> | | | >> | +-----------+ +----------------+ | | >> +--+file_y|<----+---+migration_attr | | | >> +-----------+ | +----------------+ | | >> +---+migration_data | | | >> | +----------------+<---------------+ | >> +---+migration_debug | | >> | +----------------+ | >> | +----------------+ | >> +---+migration_state +-----------------------+ >> +----------------+ >> >> The entire debugfs directory will be based on the definition of >> the CONFIG_DEBUG_FS macro. If this macro is not enabled, the >> interfaces in vfio.h will be empty definitions, and the creation >> and initialization of the debugfs directory will not be executed. >> >> debugfs will create a public root directory "vfio" file. >> then create a device named file for each live migration device. > > dev_name(), it's only for PCI devices. > Yes, this description needs revision. >> First, create a unified state acquisition file of "migration_state" >> in this device directory. >> Then, create your own debugging files independently according to >> the functional requirements of each device. >> >> Here, HiSilicon accelerator creates three debug files: >> migration_attr: used to obtain the attribute parameters of the >> current live migration device. >> migration_data: used to get the live migration data of the current >> live migration device. >> migration_debug: Used to debug the current live migration device >> through commands. >> >> The live migration function of the current device can be tested by >> operating the debug files, and the functional status of the equipment >> and software at each stage can be tested step by step without >> performing the complete live migration function. And after the live >> migration is performed, the migration device data of the live migration >> can be obtained through the debug files. >> >> Signed-off-by: Longfang Liu >> --- >> drivers/vfio/Makefile | 2 +- >> drivers/vfio/vfio.h | 14 +++++++ >> drivers/vfio/vfio_debugfs.c | 82 +++++++++++++++++++++++++++++++++++++ >> drivers/vfio/vfio_main.c | 5 +++ >> include/linux/vfio.h | 8 ++++ >> 5 files changed, 110 insertions(+), 1 deletion(-) >> create mode 100644 drivers/vfio/vfio_debugfs.c >> >> diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile >> index 70e7dcb302ef..1debcff31d30 100644 >> --- a/drivers/vfio/Makefile >> +++ b/drivers/vfio/Makefile >> @@ -7,7 +7,7 @@ vfio-y += vfio_main.o \ >> vfio-$(CONFIG_IOMMUFD) += iommufd.o >> vfio-$(CONFIG_VFIO_CONTAINER) += container.o >> vfio-$(CONFIG_VFIO_VIRQFD) += virqfd.o >> - >> +vfio-$(CONFIG_DEBUG_FS) += vfio_debugfs.o >> obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o >> obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o >> obj-$(CONFIG_VFIO_PCI) += pci/ >> diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h >> index e9721d8424bc..66c00f97e9cc 100644 >> --- a/drivers/vfio/vfio.h >> +++ b/drivers/vfio/vfio.h >> @@ -258,4 +258,18 @@ static inline void vfio_device_put_kvm(struct vfio_device *device) >> } >> #endif >> >> +#ifdef CONFIG_DEBUG_FS >> +void vfio_debugfs_create_root(void); >> +void vfio_debugfs_remove_root(void); >> + >> +void vfio_vf_debugfs_init(struct vfio_device *vdev); >> +void vfio_vf_debugfs_exit(struct vfio_device *vdev); > > s/vf_// throughout. > Yes, it is not vf anymore, the function name needs to be modified >> +#else >> +static inline void vfio_debugfs_create_root(void) { } >> +static inline void vfio_debugfs_remove_root(void) { } >> + >> +static inline void vfio_vf_debugfs_init(struct vfio_device *vdev) { } >> +static inline void vfio_vf_debugfs_exit(struct vfio_device *vdev) { } >> +#endif /* CONFIG_DEBUG_FS */ >> + >> #endif >> diff --git a/drivers/vfio/vfio_debugfs.c b/drivers/vfio/vfio_debugfs.c >> new file mode 100644 >> index 000000000000..c5df1496fe0e >> --- /dev/null >> +++ b/drivers/vfio/vfio_debugfs.c >> @@ -0,0 +1,82 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Copyright (c) 2023, HiSilicon Ltd. >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include "vfio.h" >> + >> +static struct dentry *vfio_debugfs_root; >> + >> +static int vfio_vf_state_read(struct seq_file *seq, void *data) >> +{ >> + struct device *vf_dev = seq->private; >> + struct vfio_device *vdev = container_of(vf_dev, struct vfio_device, device); >> + enum vfio_device_mig_state state; >> + int ret; >> + >> + ret = vdev->mig_ops->migration_get_state(vdev, &state); >> + if (ret) { >> + dev_err(vf_dev, "failed to get device migration state"); > > Isn't the errno below sufficient? No need to add the ability to fill > logs as well. > OK£¬I will remove it in the next version. >> + return -EINVAL; >> + } >> + >> + switch (state) { >> + case VFIO_DEVICE_STATE_RUNNING: >> + seq_printf(seq, "%s\n", "RUNNING"); >> + break; >> + case VFIO_DEVICE_STATE_STOP_COPY: >> + seq_printf(seq, "%s\n", "STOP_COPY"); >> + break; >> + case VFIO_DEVICE_STATE_STOP: >> + seq_printf(seq, "%s\n", "STOP"); >> + break; >> + case VFIO_DEVICE_STATE_RESUMING: >> + seq_printf(seq, "%s\n", "RESUMING"); >> + break; >> + case VFIO_DEVICE_STATE_RUNNING_P2P: >> + seq_printf(seq, "%s\n", "RESUMING_P2P"); >> + break; >> + case VFIO_DEVICE_STATE_ERROR: >> + seq_printf(seq, "%s\n", "ERROR"); >> + break; >> + default: >> + seq_printf(seq, "%s\n", "Invalid"); >> + } >> + >> + return 0; >> +} >> + >> +void vfio_vf_debugfs_init(struct vfio_device *vdev) >> +{ >> + struct device *dev = &vdev->device; >> + >> + vdev->debug_root = debugfs_create_dir(dev_name(vdev->dev), vfio_debugfs_root); >> + >> + debugfs_create_devm_seqfile(dev, "migration_state", vdev->debug_root, >> + vfio_vf_state_read); >> +} >> +EXPORT_SYMBOL_GPL(vfio_vf_debugfs_init); >> + >> +void vfio_vf_debugfs_exit(struct vfio_device *vdev) >> +{ >> + debugfs_remove_recursive(vdev->debug_root); >> +} >> +EXPORT_SYMBOL_GPL(vfio_vf_debugfs_exit); > > The above two should probably be vfio_device_debugfs_{init,exit}(). > OK >> + >> +void vfio_debugfs_create_root(void) >> +{ >> + vfio_debugfs_root = debugfs_create_dir("vfio", NULL); >> +} >> +EXPORT_SYMBOL_GPL(vfio_debugfs_create_root); >> + >> +void vfio_debugfs_remove_root(void) >> +{ >> + debugfs_remove_recursive(vfio_debugfs_root); >> + vfio_debugfs_root = NULL; >> +} >> +EXPORT_SYMBOL_GPL(vfio_debugfs_remove_root); > > As Jason notes, this becomes part of the vfio module, these latter two > don't need to be exported to be called by vfio_main. > Let me re-debug to see if I can delete the following exports > Thanks, > Alex > Thanks£¬ Longfang >> + >> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c >> index 3a597e799918..09772fd3a396 100644 >> --- a/drivers/vfio/vfio_main.c >> +++ b/drivers/vfio/vfio_main.c >> @@ -1408,6 +1408,9 @@ static int __init vfio_init(void) >> } >> >> pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); >> + >> + vfio_debugfs_create_root(); >> + >> return 0; >> >> err_dev_class: >> @@ -1425,6 +1428,8 @@ static void __exit vfio_cleanup(void) >> vfio_virqfd_exit(); >> vfio_group_cleanup(); >> xa_destroy(&vfio_device_set_xa); >> + >> + vfio_debugfs_remove_root(); >> } >> >> module_init(vfio_init); >> diff --git a/include/linux/vfio.h b/include/linux/vfio.h >> index 93134b023968..fa6b898ebb58 100644 >> --- a/include/linux/vfio.h >> +++ b/include/linux/vfio.h >> @@ -63,6 +63,14 @@ struct vfio_device { >> struct iommufd_ctx *iommufd_ictx; >> bool iommufd_attached; >> #endif >> + >> +#ifdef CONFIG_DEBUG_FS >> + /* >> + * debug_root is a static property of the vfio_device >> + * which must be set prior to registering the vfio_device. >> + */ >> + struct dentry *debug_root; >> +#endif >> }; >> >> /** > > . >