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 43477EB64DD for ; Mon, 24 Jul 2023 04:00:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229527AbjGXEAc (ORCPT ); Mon, 24 Jul 2023 00:00:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229486AbjGXEAb (ORCPT ); Mon, 24 Jul 2023 00:00:31 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D682BB0 for ; Sun, 23 Jul 2023 21:00:28 -0700 (PDT) Received: from kwepemm600005.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4R8RHq5cyqzrRrk; Mon, 24 Jul 2023 11:59:35 +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 15.1.2507.27; Mon, 24 Jul 2023 12:00:25 +0800 Subject: Re: [PATCH v11 4/4] Documentation: add debugfs description for vfio To: Alex Williamson CC: , , , , , References: <20230630092457.54902-1-liulongfang@huawei.com> <20230630092457.54902-5-liulongfang@huawei.com> <20230714160752.78735c4a.alex.williamson@redhat.com> From: liulongfang Message-ID: <8d670c89-833d-ef9a-ce87-b46ef8915b37@huawei.com> Date: Mon, 24 Jul 2023 12:00:25 +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: <20230714160752.78735c4a.alex.williamson@redhat.com> Content-Type: text/plain; charset="gbk" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.103.158] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) 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 2023/7/15 6:07, Alex Williamson write: > On Fri, 30 Jun 2023 17:24:57 +0800 > liulongfang wrote: > >> From: Longfang Liu >> >> 1.Add two debugfs document description file to help users understand >> how to use the accelerator live migration driver's debugfs. >> 2.Update the file paths that need to be maintained in MAINTAINERS >> >> Signed-off-by: Longfang Liu >> --- >> .../ABI/testing/debugfs-hisi-migration | 32 +++++++++++++++++++ >> Documentation/ABI/testing/debugfs-vfio | 25 +++++++++++++++ >> MAINTAINERS | 2 ++ >> 3 files changed, 59 insertions(+) >> create mode 100644 Documentation/ABI/testing/debugfs-hisi-migration >> create mode 100644 Documentation/ABI/testing/debugfs-vfio >> >> diff --git a/Documentation/ABI/testing/debugfs-hisi-migration b/Documentation/ABI/testing/debugfs-hisi-migration >> new file mode 100644 >> index 000000000000..0dfc7008a3e1 >> --- /dev/null >> +++ b/Documentation/ABI/testing/debugfs-hisi-migration >> @@ -0,0 +1,32 @@ >> +What: /sys/kernel/debug/vfio//migration/hisi_acc/data >> +Date: June 2023 >> +KernelVersion: 6.4 > > At best we'd be looking at introducing this for 6.6, where it might get > into mainline in late August for all of these. > OK, so does this KernelVersion need to be marked as 6.6? >> +Contact: Longfang Liu >> +Description: Read the live migration data of the vfio device. >> + The output format of the data is defined by the live >> + migration driver. > > This attribute is specific to the hisi_acc driver, so should the data > be detailed here? > OK I'll add a description of the role type of the data. >> + >> +What: /sys/kernel/debug/vfio//migration/hisi_acc/attr >> +Date: June 2023 >> +KernelVersion: 6.4 >> +Contact: Longfang Liu >> +Description: Read the live migration attributes of the vfio device. >> + The output format of the attributes is defined by the live >> + migration driver. > > Same here. > OK. >> + >> +What: /sys/kernel/debug/vfio//migration/hisi_acc/io_test >> +Date: June 2023 >> +KernelVersion: 6.4 >> +Contact: Longfang Liu >> +Description: Trigger the HiSilicon accelerator device to perform >> + the io test through the read operation, and directly output >> + the test result. > > This has essentially been reduced to reading the mailbox value AIUI, > should this simply document that and the resulting possible values? > OK,This can add information. >> + >> +What: /sys/kernel/debug/vfio//migration/hisi_acc/save >> +Date: June 2023 >> +KernelVersion: 6.4 >> +Contact: Longfang Liu >> +Description: Trigger the Hisilicon accelerator device to perform >> + the state saving operation of live migration through the read >> + operation, and directly output the operation result. > > It's unclear to me why we need to parse a returned string from the > debugfs seq file rather than read returns zero on success or errno on > failure. > It is impossible to know the reason for the failure just by returning true or false. Through the string obtained by seq_printf, the user can know the cause of the error. >> + >> diff --git a/Documentation/ABI/testing/debugfs-vfio b/Documentation/ABI/testing/debugfs-vfio >> new file mode 100644 >> index 000000000000..e2132a2f602b >> --- /dev/null >> +++ b/Documentation/ABI/testing/debugfs-vfio >> @@ -0,0 +1,25 @@ >> +What: /sys/kernel/debug/vfio >> +Date: June 2023 >> +KernelVersion: 6.4 >> +Contact: Longfang Liu >> +Description: This debugfs file directory is used for debugging >> + of vfio devices. >> + Each device can create a device subdirectory under this >> + directory by referencing the public registration interface. > > This suggests it's the device driver's responsibility to create those > subdirectories, but we've delegated that to the core currently. Maybe > this is suggesting that each driver can create a driver subdirectory > under the core created device directory? > OK This vfio directory file is added in vfio_main. All vfio devices share this device directory. Then each device creates its own device directory with its own dev_name. Thanks. Longfang. > Thanks, > Alex > >> + >> +What: /sys/kernel/debug/vfio//migration >> +Date: June 2023 >> +KernelVersion: 6.4 >> +Contact: Longfang Liu >> +Description: This debugfs file directory is used for debugging >> + of vfio devices that support live migration. >> + The debugfs of each vfio device that supports live migration >> + could be created under this directory. >> + >> +What: /sys/kernel/debug/vfio//migration/state >> +Date: June 2023 >> +KernelVersion: 6.4 >> +Contact: Longfang Liu >> +Description: Read the live migration status of the vfio device. >> + The status of these live migrations includes: >> + ERROR, RUNNING, STOP, STOP_COPY, RESUMING. >> diff --git a/MAINTAINERS b/MAINTAINERS >> index ce6ac552d8f6..bdd6a5e7350f 100644 >> --- a/MAINTAINERS >> +++ b/MAINTAINERS >> @@ -22098,6 +22098,7 @@ L: kvm@vger.kernel.org >> S: Maintained >> T: git https://github.com/awilliam/linux-vfio.git >> F: Documentation/ABI/testing/sysfs-devices-vfio-dev >> +F: Documentation/ABI/testing/debugfs-vfio >> F: Documentation/driver-api/vfio.rst >> F: drivers/vfio/ >> F: include/linux/vfio.h >> @@ -22115,6 +22116,7 @@ M: Longfang Liu >> M: Shameer Kolothum >> L: kvm@vger.kernel.org >> S: Maintained >> +F: Documentation/ABI/testing/debugfs-hisi-migration >> F: drivers/vfio/pci/hisilicon/ >> >> VFIO MEDIATED DEVICE DRIVERS > > . >