Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 14 Apr 2023 09:24:43 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Longfang Liu <liulongfang@huawei.com>
Cc:     alex.williamson@redhat.com, shameerali.kolothum.thodi@huawei.com,
        jonathan.cameron@huawei.com, cohuck@redhat.com,
        linux-kernel@vger.kernel.org, linuxarm@openeuler.org
Subject: Re: [PATCH v10 3/5] hisi_acc_vfio_pci: register debugfs for
 hisilicon migration driver
Message-ID: <ZDlGC8SUXqKNmfSe@nvidia.com>
References: <20230408074224.62608-1-liulongfang@huawei.com>
 <20230408074224.62608-4-liulongfang@huawei.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230408074224.62608-4-liulongfang@huawei.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?UMiPfUcQegeYKAq9QMqrNUyP18CMRtXmXkSQMcki2ZwNyy2nqOyc7UgN/PBn?=
 =?us-ascii?Q?hlwtv+FHNRx4P1wLLMzy6DOpX2GyDf37+MCbxIiwIL7kEKWBkGwHNqMyob/w?=
 =?us-ascii?Q?PXd6ClrBB9ufQ+2ovvpz7Nn4yieqAQ5Bd3vsqcL9qD65mA4Rf2NyevDw74Q0?=
 =?us-ascii?Q?c311Gy83tsSdL4eg0nNpbIdU/NE3GVpptjKgITXxopQWgO2FSMgsfLHAigCA?=
 =?us-ascii?Q?pKKUU3atflOYzawhjTui+Kv2Kf0gqlmVB8tS0jMM6+Kh+y1Ycxqe93PBv9lR?=
 =?us-ascii?Q?FO0AMu7LducmoWYXRgeI980BWPxPAt8ikBuBeU4LwmBJ1/NkRMnisbLp5F6m?=
 =?us-ascii?Q?RHSrNDPFh90BBzHzAeb5F01+NL9/V7vl2C2T/rTMZ8tdRtiE/ldr0qp7m2Pf?=
 =?us-ascii?Q?Qvby4pBETI1XmwS/T1Tl6ulfuFbcPGT4JP+sSsPpjj4d9Okk89H/6TEiR1kL?=
 =?us-ascii?Q?dZzRBymmFX2wcxc221/8AwqRbzRDd9QWvKxqlX0WSLcN4ISh6B3pHM3YZd9H?=
 =?us-ascii?Q?Qrn8v0Lt9RlXlasbVEESiIIdYrPGqf9VceSWNeVL4Bry6a5Q4/J6boM849Mz?=
 =?us-ascii?Q?a+MOk9j/RZTwKsQiMe4O52ZOHQEWElvhDDOAHSqaK/bnk2r2HWsQp8ychVHU?=
 =?us-ascii?Q?DYwuabCxFkkniJKwYF12Tujkr+zq1Tz5z2+V2E0qag2zkcbpFBAUYpyixFRd?=
 =?us-ascii?Q?zPTdMRQ0roEhB1+5quevX8AQUTAnwQgREBrGVEWGWp5AZDiYoPQ6M450Emdq?=
 =?us-ascii?Q?IE27M20So9jTWp6nQCp0BjtbPpSVIUN72KB+KwY+DM1lNTPzRwue3nKnFBtP?=
 =?us-ascii?Q?vQeufwgwIIXlEL3njUAgZdasVu47i99HZT9PewStVfX+IBPNx0N/y4JCtl/2?=
 =?us-ascii?Q?Epf/nWZvxaiERzu7McBVy6rLZwJQxCVYPw5ZPCU+zZ/u8YQKg9HsnDWdhbKN?=
 =?us-ascii?Q?c/KFxqOsv1JlVU/OxlbgXvwPbtby1vINoqH+omyTplwPtd/EIg6BMmGzZS+S?=
 =?us-ascii?Q?6UmHhctuLeCKLCfRsKo+TuFja024Nqx7TnVCBN30SD0x36KjkQ2aSmib66a+?=
 =?us-ascii?Q?JpZoYAX085nVAUmK41n40unu9UCaUWKKRIjlMSBNmQjou9xhtA8STOHPdZTB?=
 =?us-ascii?Q?TAreXT68p9fdVkh2gfqPJcf7Dvy4XMngL5PIfd5pvtpll5PaxZjo/SHHcLBe?=
 =?us-ascii?Q?6+8Wb2E8KDfMg8PIvxzqyx0p2+oyuBPNb/1ZcQHp7tGQht25HWLCzX6GSzDd?=
 =?us-ascii?Q?JyJBQv1q2ObF1vPynN8mmtgLVoJSA2UhoN6p+0ra1DcA531i8WVvxXuA2+Wl?=
 =?us-ascii?Q?lOH4YjYWQjgaVB5cH9QtuiB3f/D2GA7iJOvb8ZzzCFJENlX4BHqn+odtKcmO?=
 =?us-ascii?Q?W5pwmxHdS2oxoL4Rq8FluRiTC3DIzHNl1uLVWA3T70wp4IFsZ0RqnLTdlZjC?=
 =?us-ascii?Q?mWBXLos/wMtELcJnhJ6MYwo24+OOkZwMICMQvwF2q+9USuKWeo3SBV+b4GTL?=
 =?us-ascii?Q?FkfjeNj55f49wQiZHc3CczQ2WbcsNu5iG7v8N8CmXPm5wfRMQ4l+GhCh74KO?=
 =?us-ascii?Q?ILCmCrvopZN+JFC52H6XNhMsfwDHhjMWJunDQaKl?=
X-OriginatorOrg: Nvidia.com
X-MS-Exchange-CrossTenant-Network-Message-Id: ae1af007-750e-421b-7693-08db3ce33bae
X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Apr 2023 12:24:46.1812
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: phPM81bPPCqUP/M+nkkrh+EynSzGa2vUYwVLX6R6eLmqeQD9agzlLUuiHG5lDtrk
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB7138
X-Spam-Status: No, score=-1.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,
        T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sat, Apr 08, 2023 at 03:42:22PM +0800, Longfang Liu wrote:
> +static int hisi_acc_vf_debug_restore(struct seq_file *seq, void *data)
> +{
> +	struct device *vf_dev = seq->private;
> +	struct vfio_pci_core_device *core_device = dev_get_drvdata(vf_dev);
> +	struct vfio_device	*vdev = &core_device->vdev;
> +	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
> +	struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
> +	int ret;
> +
> +	ret = hisi_acc_vf_debug_check(seq, vdev);
> +	if (ret)
> +		goto restore_err;
> +
> +	ret = vf_qm_state_save(hisi_acc_vdev, migf);
> +	if (ret) {
> +		seq_printf(seq, "%s\n", "failed to save device data!");
> +		goto restore_err;
> +	}
> +
> +	ret = vf_qm_check_match(hisi_acc_vdev, migf);
> +	if (ret) {
> +		seq_printf(seq, "%s\n", "failed to match the VF!");
> +		goto restore_err;
> +	}
> +
> +	ret = vf_qm_load_data(hisi_acc_vdev, migf);
> +	if (ret) {
> +		seq_printf(seq, "%s\n", "failed to recover the VF!");
> +		goto restore_err;
> +	}
> +
> +	vf_qm_fun_reset(&hisi_acc_vdev->vf_qm);
> +	seq_printf(seq, "%s\n", "successful to resume device data!");
> +
> +restore_err:
> +	return 0;
> +}

This is basically an in-kernel self test, it should be protected with
some kind of VFIO selftest kconfig.

Though, I wonder why we need it??? Can't you write a trivial userspace
program under tools/testing to do this sequence with the ioctls?

> +static int hisi_acc_vf_debug_save(struct seq_file *seq, void *data)
> +{
> +	struct device *vf_dev = seq->private;
> +	struct vfio_pci_core_device *core_device = dev_get_drvdata(vf_dev);
> +	struct vfio_device	*vdev = &core_device->vdev;
> +	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
> +	struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
> +	int ret;
> +
> +	ret = hisi_acc_vf_debug_check(seq, vdev);
> +	if (ret)
> +		goto save_err;
> +
> +	ret = vf_qm_state_save(hisi_acc_vdev, migf);
> +	if (ret) {
> +		seq_printf(seq, "%s\n", "failed to save device data!");
> +		goto save_err;
> +	}
> +	seq_printf(seq, "%s\n", "successful to save device data!");
> +
> +save_err:
> +	return 0;
> +}

Same kind of commen there, this is a selftest, why does it need a
special kernel interface?

.. and so on..

I thought the non-selftesty bits were OK, maybe split the patch to
match progress

Jason