From patchwork Tue Sep 26 09:33:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: liulongfang X-Patchwork-Id: 13398955 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 2C8E7E7D271 for ; Tue, 26 Sep 2023 09:37:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234187AbjIZJhZ (ORCPT ); Tue, 26 Sep 2023 05:37:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233835AbjIZJhX (ORCPT ); Tue, 26 Sep 2023 05:37:23 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1641B3; Tue, 26 Sep 2023 02:37:16 -0700 (PDT) Received: from kwepemm000005.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4RvvjJ3m4zzrSrZ; Tue, 26 Sep 2023 17:35:00 +0800 (CST) Received: from huawei.com (10.50.163.32) by kwepemm000005.china.huawei.com (7.193.23.27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Tue, 26 Sep 2023 17:37:14 +0800 From: liulongfang To: , , , CC: , , , , Subject: [PATCH v16 1/2] vfio/migration: Add debugfs to live migration driver Date: Tue, 26 Sep 2023 17:33:55 +0800 Message-ID: <20230926093356.56014-2-liulongfang@huawei.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20230926093356.56014-1-liulongfang@huawei.com> References: <20230926093356.56014-1-liulongfang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.163.32] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm000005.china.huawei.com (7.193.23.27) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Longfang Liu 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 | | | | | +---+----------------------------+----------+ | ^ | ^ | | | | | | | | v | v | +---------+--+ +---------+--+ |src vfio_dev| |dst vfio_dev| +--+---------+ +--+---------+ | ^ | ^ | | | | v | | | +-----------+----+ +-----------+----+ |src dev debugfs | |dst dev debugfs | +----------------+ +----------------+ 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. vfio | +--- | +---migration | +--state | +--- +---migration +--state debugfs will create a public root directory "vfio" file. then create a dev_name() file for each live migration device. First, create a unified state acquisition file of "migration" in this device directory. Then, create a public live migration state lookup file "state" Finally, create a directory file based on the device type, and then create the device's own debugging files under this directory file. Signed-off-by: Longfang Liu --- drivers/vfio/Makefile | 1 + drivers/vfio/vfio.h | 14 ++++++ drivers/vfio/vfio_debugfs.c | 87 +++++++++++++++++++++++++++++++++++++ drivers/vfio/vfio_main.c | 14 +++++- include/linux/vfio.h | 7 +++ 5 files changed, 121 insertions(+), 2 deletions(-) create mode 100644 drivers/vfio/vfio_debugfs.c diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile index c82ea032d352..7934ac829989 100644 --- a/drivers/vfio/Makefile +++ b/drivers/vfio/Makefile @@ -8,6 +8,7 @@ vfio-$(CONFIG_VFIO_GROUP) += group.o vfio-$(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 diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index 307e3f29b527..09b00757d0bb 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -448,4 +448,18 @@ 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_device_debugfs_init(struct vfio_device *vdev); +void vfio_device_debugfs_exit(struct vfio_device *vdev); +#else +static inline void vfio_debugfs_create_root(void) { } +static inline void vfio_debugfs_remove_root(void) { } + +static inline void vfio_device_debugfs_init(struct vfio_device *vdev) { } +static inline void vfio_device_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..b79bdef08357 --- /dev/null +++ b/drivers/vfio/vfio_debugfs.c @@ -0,0 +1,87 @@ +// 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_device_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) + return -EINVAL; + + switch (state) { + case VFIO_DEVICE_STATE_STOP: + seq_printf(seq, "%s\n", "STOP"); + break; + 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_RESUMING: + seq_printf(seq, "%s\n", "RESUMING"); + break; + case VFIO_DEVICE_STATE_RUNNING_P2P: + seq_printf(seq, "%s\n", "RUNNING_P2P"); + break; + case VFIO_DEVICE_STATE_PRE_COPY: + seq_printf(seq, "%s\n", "PRE_COPY"); + break; + case VFIO_DEVICE_STATE_PRE_COPY_P2P: + seq_printf(seq, "%s\n", "PRE_COPY_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_device_debugfs_init(struct vfio_device *vdev) +{ + struct device *dev = &vdev->device; + + vdev->debug_root = debugfs_create_dir(dev_name(vdev->dev), vfio_debugfs_root); + + if (vdev->mig_ops) { + struct dentry *vfio_dev_migration = NULL; + + vfio_dev_migration = debugfs_create_dir("migration", vdev->debug_root); + debugfs_create_devm_seqfile(dev, "state", vfio_dev_migration, + vfio_device_state_read); + } +} + +void vfio_device_debugfs_exit(struct vfio_device *vdev) +{ + debugfs_remove_recursive(vdev->debug_root); +} + +void vfio_debugfs_create_root(void) +{ + vfio_debugfs_root = debugfs_create_dir("vfio", NULL); +} + +void vfio_debugfs_remove_root(void) +{ + debugfs_remove_recursive(vfio_debugfs_root); + vfio_debugfs_root = NULL; +} + diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index cfad824d9aa2..4e3ced20d2d1 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -309,7 +309,6 @@ static int __vfio_register_dev(struct vfio_device *device, /* Refcounting can't start until the driver calls register */ refcount_set(&device->refcount, 1); - vfio_device_group_register(device); return 0; @@ -320,7 +319,15 @@ static int __vfio_register_dev(struct vfio_device *device, int vfio_register_group_dev(struct vfio_device *device) { - return __vfio_register_dev(device, VFIO_IOMMU); + int ret; + + ret = __vfio_register_dev(device, VFIO_IOMMU); + if (ret) + return ret; + + vfio_device_debugfs_init(device); + + return 0; } EXPORT_SYMBOL_GPL(vfio_register_group_dev); @@ -378,6 +385,7 @@ void vfio_unregister_group_dev(struct vfio_device *device) } } + vfio_device_debugfs_exit(device); /* Balances vfio_device_set_group in register path */ vfio_device_remove_group(device); } @@ -1662,6 +1670,7 @@ static int __init vfio_init(void) if (ret) goto err_alloc_dev_chrdev; + vfio_debugfs_create_root(); pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); return 0; @@ -1677,6 +1686,7 @@ static int __init vfio_init(void) static void __exit vfio_cleanup(void) { + vfio_debugfs_remove_root(); ida_destroy(&vfio.device_ida); vfio_cdev_cleanup(); class_destroy(vfio.device_class); diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 454e9295970c..769d7af86225 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -69,6 +69,13 @@ struct vfio_device { u8 iommufd_attached:1; #endif u8 cdev_opened:1; +#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 }; /**