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.
> > +{
> > + 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.
> > +}
> > +
> > 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?
> > +
> > +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.
> > + 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
> > + kfree(hisi_acc_vdev->debug_migf);
> > + hisi_acc_vdev->debug_migf = NULL;
> > +}
> > +
>
