On 2024/11/6 2:21, Alex Williamson wrote:
> On Tue, 5 Nov 2024 08:55:51 +0000
> Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx> wrote:
>
>>> -----Original Message-----
>>> From: liulongfang <liulongfang@xxxxxxxxxx>
>>> Sent: Tuesday, November 5, 2024 3:53 AM
>>> To: alex.williamson@xxxxxxxxxx; jgg@xxxxxxxxxx; Shameerali Kolothum
>>> Thodi <shameerali.kolothum.thodi@xxxxxxxxxx>; Jonathan Cameron
>>> <jonathan.cameron@xxxxxxxxxx>
>>> Cc: kvm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
>>> linuxarm@xxxxxxxxxxxxx; liulongfang <liulongfang@xxxxxxxxxx>
>>> Subject: [PATCH v12 3/4] hisi_acc_vfio_pci: register debugfs for hisilicon
>>> migration driver
>>
>> Hi,
>>
>> Few minor comments below. Please don't re-spin just for these yet.
>> Please wait for others to review as well.
>>
>> Thanks,
>> Shameer
>>
>>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>>> b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>>> index a8c53952d82e..7728c9745b9d 100644
>>> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>>> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>>> @@ -627,15 +627,30 @@ static void hisi_acc_vf_disable_fd(struct
>>> hisi_acc_vf_migration_file *migf)
>>> mutex_unlock(&migf->lock);
>>> }
>>>
>>> +static void hisi_acc_debug_migf_copy(struct hisi_acc_vf_core_device
>>> *hisi_acc_vdev,
>>> + struct hisi_acc_vf_migration_file *src_migf)
>>
>> Alignment should match open parenthesis here.
>
> I might also shorten the first line to 80 chars by putting "static" or
> "static void" on a line by itself, but we're getting into personal
> preference at that point and this driver already has lines exceeding 80
> columns.
>
Okay, I put static void on a separate line,
and the following two are aligned.
>>> +{
>>> + struct hisi_acc_vf_migration_file *dst_migf = hisi_acc_vdev-
>>>> debug_migf;
>>> +
>>> + if (!dst_migf)
>>> + return;
>>> +
>>> + dst_migf->total_length = src_migf->total_length;
>>> + memcpy(&dst_migf->vf_data, &src_migf->vf_data,
>>> + sizeof(struct acc_vf_data));
>>
>> Here too, alignment not correct. It is better to run,
>> ./scripts/checkpatch --strict on these patches if you haven't done already.
>
> Yup. Only those two were missed as far as I see, but checkpatch does
> warn several places where we should use seq_puts() rather than
> seq_printf() for cases of printing a constant format without additional
> arguments. For example "device not opened!\n" is the first one below
> but there are others.
>
OK!
I will use "./scripts/checkpatch --strict" to handle it,
and replace seq_printf() with seq_puts()
>>> +}
>>> +
>>> static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device
>>> *hisi_acc_vdev)
>>> {
>>> if (hisi_acc_vdev->resuming_migf) {
>>> + hisi_acc_debug_migf_copy(hisi_acc_vdev, hisi_acc_vdev-
>>>> resuming_migf);
>>> hisi_acc_vf_disable_fd(hisi_acc_vdev->resuming_migf);
>>> fput(hisi_acc_vdev->resuming_migf->filp);
>>> hisi_acc_vdev->resuming_migf = NULL;
>>> }
>>>
>>> if (hisi_acc_vdev->saving_migf) {
>>> + hisi_acc_debug_migf_copy(hisi_acc_vdev, hisi_acc_vdev-
>>>> saving_migf);
>>> hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf);
>>> fput(hisi_acc_vdev->saving_migf->filp);
>>> hisi_acc_vdev->saving_migf = NULL;
>>> @@ -1294,6 +1309,129 @@ static long hisi_acc_vfio_pci_ioctl(struct
>>> vfio_device *core_vdev, unsigned int
>>> return vfio_pci_core_ioctl(core_vdev, cmd, arg);
>>> }
>>>
>>> +static int hisi_acc_vf_debug_check(struct seq_file *seq, struct vfio_device
>>> *vdev)
>>> +{
>>> + struct hisi_acc_vf_core_device *hisi_acc_vdev =
>>> hisi_acc_get_vf_dev(vdev);
>>> + struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm;
>>> + int ret;
>>> +
>>> + lockdep_assert_held(&hisi_acc_vdev->open_mutex);
>>> + /*
>>> + * When the device is not opened, the io_base is not mapped.
>>> + * The driver cannot perform device read and write operations.
>>> + */
>>> + if (!hisi_acc_vdev->dev_opened) {
>>> + seq_printf(seq, "device not opened!\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + ret = qm_wait_dev_not_ready(vf_qm);
>>> + if (ret) {
>>> + seq_printf(seq, "VF device not ready!\n");
>>> + return -EBUSY;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int hisi_acc_vf_debug_cmd(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_qm *vf_qm = &hisi_acc_vdev->vf_qm;
>>> + u64 value;
>>> + int ret;
>>> +
>>> + mutex_lock(&hisi_acc_vdev->open_mutex);
>>> + ret = hisi_acc_vf_debug_check(seq, vdev);
>>> + if (ret) {
>>> + mutex_unlock(&hisi_acc_vdev->open_mutex);
>>> + return ret;
>>> + }
>>> +
>>> + value = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
>>> + if (value == QM_MB_CMD_NOT_READY) {
>>> + mutex_unlock(&hisi_acc_vdev->open_mutex);
>>> + seq_printf(seq, "mailbox cmd channel not ready!\n");
>>> + return -EINVAL;
>>> + }
>>> + mutex_unlock(&hisi_acc_vdev->open_mutex);
>>> + seq_printf(seq, "mailbox cmd channel ready!\n");
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int hisi_acc_vf_dev_read(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);
>>> + size_t vf_data_sz = offsetofend(struct acc_vf_data, padding);
>>> + struct acc_vf_data *vf_data;
>>> + int ret;
>>> +
>>> + mutex_lock(&hisi_acc_vdev->open_mutex);
>>> + ret = hisi_acc_vf_debug_check(seq, vdev);
>>> + if (ret) {
>>> + mutex_unlock(&hisi_acc_vdev->open_mutex);
>>> + return ret;
>>> + }
>>> +
>>> + mutex_lock(&hisi_acc_vdev->state_mutex);
>>> + vf_data = kzalloc(sizeof(struct acc_vf_data), GFP_KERNEL);
>>> + if (!vf_data) {
>>> + ret = -ENOMEM;
>>> + goto mutex_release;
>>> + }
>>> +
>>> + vf_data->vf_qm_state = hisi_acc_vdev->vf_qm_state;
>>> + ret = vf_qm_read_data(&hisi_acc_vdev->vf_qm, vf_data);
>>> + if (ret)
>>> + goto migf_err;
>>> +
>>> + seq_hex_dump(seq, "Dev Data:", DUMP_PREFIX_OFFSET, 16, 1,
>>> + (const void *)vf_data, vf_data_sz, false);
>>> +
>>> + seq_printf(seq,
>>> + "guest driver load: %u\n"
>>> + "data size: %lu\n",
>>> + hisi_acc_vdev->vf_qm_state,
>>> + sizeof(struct acc_vf_data));
>>
>> There was a suggestion to add a comment here to describe vf_qm_state better.
>> May be something like,
>>
>> vf_qm_state here indicates whether the Guest has loaded the driver for the ACC VF
>> device or not.
>
> I think the comment ended up at the declaration of vf_qm_state in the
> header file:
>>> @@ -107,9 +114,17 @@ struct hisi_acc_vf_core_device {
>> struct pci_dev *vf_dev;
>> struct hisi_qm *pf_qm;
>> struct hisi_qm vf_qm;
>> + /*
>> + * Record whether a driver is added to the acc device in Guest OS.
>> + * The value of QM_VF_STATE is set by the acc device driver.
>> + * The migration driver queries through the QM_VF_STATE register.
>> + */
>> u32 vf_qm_state;
>> int vf_id;
>> struct hisi_acc_vf_migration_file *resuming_migf;
>> struct hisi_acc_vf_migration_file *saving_migf;
>> +
>> + /* An extra buffer for reporting migration data via debugfs */
>> + struct hisi_acc_vf_migration_file *debug_migf;
>> };
>> #endif /* HISI_ACC_VFIO_PCI_H */
>
> Is that satisfactory?
>
Okay, I'll update the comment.
>>> +
>>> +migf_err:
>>> + kfree(vf_data);
>>> +mutex_release:
>>> + mutex_unlock(&hisi_acc_vdev->state_mutex);
>>> + mutex_unlock(&hisi_acc_vdev->open_mutex);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int hisi_acc_vf_migf_read(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);
>>> + size_t vf_data_sz = offsetofend(struct acc_vf_data, padding);
>>> + struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev-
>>>> debug_migf;
>>> +
>>> + /* Check whether the live migration operation has been performed
>>> */
>>> + if (debug_migf->total_length < QM_MATCH_SIZE) {
>>> + seq_printf(seq, "device not migrated!\n");
>>> + return -EAGAIN;
>>> + }
>>> +
>>> + seq_hex_dump(seq, "Mig Data:", DUMP_PREFIX_OFFSET, 16, 1,
>>> + (const void *)&debug_migf->vf_data, vf_data_sz, false);
>>> + seq_printf(seq, "migrate data length: %lu\n", debug_migf-
>>>> total_length);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev)
>>> {
>>> struct hisi_acc_vf_core_device *hisi_acc_vdev =
>>> hisi_acc_get_vf_dev(core_vdev);
>>> @@ -1305,12 +1443,16 @@ static int hisi_acc_vfio_pci_open_device(struct
>>> vfio_device *core_vdev)
>>> return ret;
>>>
>>> if (core_vdev->mig_ops) {
>>> + mutex_lock(&hisi_acc_vdev->open_mutex);
>>> ret = hisi_acc_vf_qm_init(hisi_acc_vdev);
>>> if (ret) {
>>> + mutex_unlock(&hisi_acc_vdev->open_mutex);
>>> vfio_pci_core_disable(vdev);
>>> return ret;
>>> }
>>> hisi_acc_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
>>> + hisi_acc_vdev->dev_opened = true;
>>> + mutex_unlock(&hisi_acc_vdev->open_mutex);
>>> }
>>>
>>> vfio_pci_core_finish_enable(vdev);
>>> @@ -1322,7 +1464,10 @@ static void hisi_acc_vfio_pci_close_device(struct
>>> vfio_device *core_vdev)
>>> struct hisi_acc_vf_core_device *hisi_acc_vdev =
>>> hisi_acc_get_vf_dev(core_vdev);
>>> struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm;
>>>
>>> + mutex_lock(&hisi_acc_vdev->open_mutex);
>>> + hisi_acc_vdev->dev_opened = false;
>>> iounmap(vf_qm->io_base);
>>> + mutex_unlock(&hisi_acc_vdev->open_mutex);
>>> vfio_pci_core_close_device(core_vdev);
>>> }
>>>
>>> @@ -1342,6 +1487,7 @@ static int hisi_acc_vfio_pci_migrn_init_dev(struct
>>> vfio_device *core_vdev)
>>> hisi_acc_vdev->pf_qm = pf_qm;
>>> hisi_acc_vdev->vf_dev = pdev;
>>> mutex_init(&hisi_acc_vdev->state_mutex);
>>> + mutex_init(&hisi_acc_vdev->open_mutex);
>>>
>>> core_vdev->migration_flags = VFIO_MIGRATION_STOP_COPY |
>>> VFIO_MIGRATION_PRE_COPY;
>>> core_vdev->mig_ops = &hisi_acc_vfio_pci_migrn_state_ops;
>>> @@ -1387,6 +1533,48 @@ static const struct vfio_device_ops
>>> hisi_acc_vfio_pci_ops = {
>>> .detach_ioas = vfio_iommufd_physical_detach_ioas,
>>> };
>>>
>>> +static void hisi_acc_vfio_debug_init(struct hisi_acc_vf_core_device
>>> *hisi_acc_vdev)
>>> +{
>>> + struct vfio_device *vdev = &hisi_acc_vdev->core_device.vdev;
>>> + struct dentry *vfio_dev_migration = NULL;
>>> + struct dentry *vfio_hisi_acc = NULL;
>>> + struct device *dev = vdev->dev;
>>> + void *migf = NULL;
>>> +
>>> + if (!debugfs_initialized() ||
>>> + !IS_ENABLED(CONFIG_VFIO_DEBUGFS))
>>> + return;
>>> +
>>> + if (vdev->ops != &hisi_acc_vfio_pci_migrn_ops)
>>> + return;
>>> +
>>> + vfio_dev_migration = debugfs_lookup("migration", vdev-
>>>> debug_root);
>>> + if (!vfio_dev_migration) {
>>> + dev_err(dev, "failed to lookup migration debugfs file!\n");
>>> + return;
>>> + }
>>> +
>>> + migf = kzalloc(sizeof(struct hisi_acc_vf_migration_file),
>>> GFP_KERNEL);
>
> checkpatch --strict also advises this could be written as:
>
> migf = kzalloc(sizeof(*migf), GFP_KERNEL);
>
> There's another one above with acc_vf_data. I'd consider these
> optional, but I think it is good practice and is more consistent with
> existing allocations in this file.
>
OK, I will modify the two "kzalloc" together.
>>> + if (!migf)
>>> + return;
>>> + hisi_acc_vdev->debug_migf = migf;
>>> +
>>> + vfio_hisi_acc = debugfs_create_dir("hisi_acc", vfio_dev_migration);
>>> + debugfs_create_devm_seqfile(dev, "dev_data", vfio_hisi_acc,
>>> + hisi_acc_vf_dev_read);
>>> + debugfs_create_devm_seqfile(dev, "migf_data", vfio_hisi_acc,
>>> + hisi_acc_vf_migf_read);
>>> + debugfs_create_devm_seqfile(dev, "cmd_state", vfio_hisi_acc,
>>> + hisi_acc_vf_debug_cmd);
>>> +}
>>> +
>>> +static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device
>>> *hisi_acc_vdev)
>>> +{
>>> + /* If migrn_ops is not used, kfree(NULL) is valid */
>>
>> The above comment is not required. Please remove.
>
> I don't have a problem with it, but I'll let the two of you decide as
> co-owners of the file. Thanks,
>
> Alex
>
OK, I'll delete it.
Thanks.
Longfang.
>
>>> + kfree(hisi_acc_vdev->debug_migf);
>>> + hisi_acc_vdev->debug_migf = NULL;
>>> +}
>>> +
>>
>
>
> .
>
