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 80EDAC6FA99 for ; Fri, 10 Mar 2023 23:41:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231939AbjCJXlR (ORCPT ); Fri, 10 Mar 2023 18:41:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231553AbjCJXlO (ORCPT ); Fri, 10 Mar 2023 18:41:14 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9527A149D3A for ; Fri, 10 Mar 2023 15:40:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678491627; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+SZk+kjuOmBaM+9g9wuTXwQmzK0YT62sqtbUHm39Upo=; b=OzCbyeeX06Hn8Agn3NjQfZVpl+Z836P3+WwkV0/znYr3sWUSK332a2krQgOuk50IYfojyr LVMTzjTRHIJ1xCXipUn4Vp6wdj0AgAB0HhTkE1yhdz/NP/XtTQmsrgF2NqgIojP0jqtCyY 6+3Lk306fPIkJWIxXTCfiai1b1ZgeiE= Received: from mail-io1-f69.google.com (mail-io1-f69.google.com [209.85.166.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-333-EPmQUyDTMfWLbVVxcmZHdQ-1; Fri, 10 Mar 2023 18:40:25 -0500 X-MC-Unique: EPmQUyDTMfWLbVVxcmZHdQ-1 Received: by mail-io1-f69.google.com with SMTP id w4-20020a5d9604000000b0074d326b26bcso3279861iol.9 for ; Fri, 10 Mar 2023 15:40:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678491625; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+SZk+kjuOmBaM+9g9wuTXwQmzK0YT62sqtbUHm39Upo=; b=4dudwO25zwC5LVTAuTxdUljMRvdmudLBZm7fx5kMP16f3Je4UEZDu76uua75eigQiX MGL2nHdzna8iBcHPzl2nABD5asWuvyf3q11Qg9OrP0sdvc+1d5WLY75jzZu5+b4iB7ri 0+LUSaCXIpmDZpxQQDHS2qsnYSHiQmp/R8RtAlEnx2ur2jsvrZoBc8G9pTIVMxqpa8pZ Dk9f1U1Q1WfTHEWm/0bgOOTuzBZlmDhOv+YKAG6T/lXayLXWhy3eqKfxLsc3wDO8ZzgA IuCSpnI5tJSiZC9BPo9hzCIYruCLlgebzjZiVm5pO2wROEtfqVAQPPZbduobm9bqVlc9 Df1A== X-Gm-Message-State: AO0yUKWvxoUzyHmFZfVxbE4Hk82rJ3nhdwDdZoP+FIvc8aGQ1wuRb/zY xxMNfR+tvKfnJf06QciiRSsC1hg5oRfqS9Edm1cpoguFo20RwwMzeu4iObA36KXbHNJ0/hE+xwW V79kHtd+hkgo0Lr3qeQBij1VC X-Received: by 2002:a92:5207:0:b0:316:e453:537c with SMTP id g7-20020a925207000000b00316e453537cmr7355841ilb.11.1678491625195; Fri, 10 Mar 2023 15:40:25 -0800 (PST) X-Google-Smtp-Source: AK7set+REdhlL1r3Fv32NIqYuPPDTE9GUmWFzBz5miovUp55GizUGeH5iHAMXU2QAR66SIAzGxRzkQ== X-Received: by 2002:a92:5207:0:b0:316:e453:537c with SMTP id g7-20020a925207000000b00316e453537cmr7355833ilb.11.1678491624856; Fri, 10 Mar 2023 15:40:24 -0800 (PST) Received: from redhat.com ([38.15.36.239]) by smtp.gmail.com with ESMTPSA id x16-20020a029710000000b003bf39936d1esm371961jai.131.2023.03.10.15.40.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Mar 2023 15:40:24 -0800 (PST) Date: Fri, 10 Mar 2023 16:40:07 -0700 From: Alex Williamson To: Longfang Liu Cc: , , , , , Subject: Re: [PATCH v8 1/5] vfio/migration: Add debugfs to live migration driver Message-ID: <20230310164007.301adce8.alex.williamson@redhat.com> In-Reply-To: <20230217084831.35783-2-liulongfang@huawei.com> References: <20230217084831.35783-1-liulongfang@huawei.com> <20230217084831.35783-2-liulongfang@huawei.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.35; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. > 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. > +#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. > + 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}(). > + > +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. Thanks, Alex > + > 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 > }; > > /**