[PATCH v2 0/3] add debugfs to hisilicon migration driver

[PATCH v2 0/3] add debugfs to hisilicon migration driver

[Longfang Liu]

Add a debugfs function to the hisilicon migration driver in VFIO to
provide intermediate state values and data during device migration.

When the execution of live migration fails, the user can view the
status and data during the migration process separately from the
source and the destination, which is convenient for users to analyze
and locate problems.

Changes v1 -> v2
	Solve the racy problem of io_base.

Longfang Liu (3):
  hisi_acc_vfio_pci: extract public functions for container_of
  hisi_acc_vfio_pci: register debugfs for hisilicon migration driver
  Documentation: add debugfs description for hisi migration

 .../ABI/testing/debugfs-hisi-migration        |  34 +++
 MAINTAINERS                                   |   1 +
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 218 +++++++++++++++++-
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  11 +
 4 files changed, 254 insertions(+), 10 deletions(-)
 create mode 100644 Documentation/ABI/testing/debugfs-hisi-migration

-- 
2.24.0

[PATCH v2 1/3] hisi_acc_vfio_pci: extract public functions for container_of

[Longfang Liu]

In the current driver, vdev is obtained from struct
hisi_acc_vf_core_device through the container_of function.
This method is used in many places in the driver. In order to
reduce this repetitive operation, It was extracted into
a public function.

Signed-off-by: Longfang Liu <liulongfang@huawei.com>
---
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 21 ++++++++++---------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index 4d27465c8f1a..00a22a990eb8 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -630,6 +630,12 @@ static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device *hisi_acc_vde
 	}
 }
 
+static struct hisi_acc_vf_core_device *hisi_acc_get_vf_dev(struct vfio_device *vdev)
+{
+	return container_of(vdev, struct hisi_acc_vf_core_device,
+			    core_device.vdev);
+}
+
 /*
  * This function is called in all state_mutex unlock cases to
  * handle a 'deferred_reset' if exists.
@@ -1045,8 +1051,7 @@ static struct file *
 hisi_acc_vfio_pci_set_device_state(struct vfio_device *vdev,
 				   enum vfio_device_mig_state new_state)
 {
-	struct hisi_acc_vf_core_device *hisi_acc_vdev = container_of(vdev,
-			struct hisi_acc_vf_core_device, core_device.vdev);
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
 	enum vfio_device_mig_state next_state;
 	struct file *res = NULL;
 	int ret;
@@ -1087,8 +1092,7 @@ static int
 hisi_acc_vfio_pci_get_device_state(struct vfio_device *vdev,
 				   enum vfio_device_mig_state *curr_state)
 {
-	struct hisi_acc_vf_core_device *hisi_acc_vdev = container_of(vdev,
-			struct hisi_acc_vf_core_device, core_device.vdev);
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
 
 	mutex_lock(&hisi_acc_vdev->state_mutex);
 	*curr_state = hisi_acc_vdev->mig_state;
@@ -1304,8 +1308,7 @@ static long hisi_acc_vfio_pci_ioctl(struct vfio_device *core_vdev, unsigned int
 
 static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev)
 {
-	struct hisi_acc_vf_core_device *hisi_acc_vdev = container_of(core_vdev,
-			struct hisi_acc_vf_core_device, core_device.vdev);
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(core_vdev);
 	struct vfio_pci_core_device *vdev = &hisi_acc_vdev->core_device;
 	int ret;
 
@@ -1328,8 +1331,7 @@ static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev)
 
 static void hisi_acc_vfio_pci_close_device(struct vfio_device *core_vdev)
 {
-	struct hisi_acc_vf_core_device *hisi_acc_vdev = container_of(core_vdev,
-			struct hisi_acc_vf_core_device, core_device.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;
 
 	iounmap(vf_qm->io_base);
@@ -1344,8 +1346,7 @@ static const struct vfio_migration_ops hisi_acc_vfio_pci_migrn_state_ops = {
 
 static int hisi_acc_vfio_pci_migrn_init_dev(struct vfio_device *core_vdev)
 {
-	struct hisi_acc_vf_core_device *hisi_acc_vdev = container_of(core_vdev,
-			struct hisi_acc_vf_core_device, core_device.vdev);
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(core_vdev);
 	struct pci_dev *pdev = to_pci_dev(core_vdev->dev);
 	struct hisi_qm *pf_qm = hisi_acc_get_pf_qm(pdev);
 
-- 
2.24.0

[PATCH v2 2/3] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

[Longfang Liu]

On the debugfs framework of VFIO, if the CONFIG_VFIO_DEBUGFS macro is
enabled, the debug function is registered for the live migration driver
of the HiSilicon accelerator device.

After registering the HiSilicon accelerator device on the debugfs
framework of live migration of vfio, a directory file "hisi_acc"
of debugfs is created, and then three debug function files are
created in this directory:

   vfio
    |
    +---<dev_name1>
    |    +---migration
    |        +--state
    |        +--hisi_acc
    |            +--attr
    |            +--data
    |            +--save
    |            +--cmd_state
    |
    +---<dev_name2>
         +---migration
             +--state
             +--hisi_acc
                 +--attr
                 +--data
                 +--save
                 +--cmd_state

data file: used to get the migration data from the driver
attr file: used to get device attributes parameters from the driver
save file: used to read the data of the live migration device and save
it to the driver.
cmd_state: used to get the cmd channel state for the device.

Signed-off-by: Longfang Liu <liulongfang@huawei.com>
---
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 197 ++++++++++++++++++
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  11 +
 2 files changed, 208 insertions(+)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index 00a22a990eb8..e51bbb41c2b3 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -15,6 +15,7 @@
 #include <linux/anon_inodes.h>
 
 #include "hisi_acc_vfio_pci.h"
+#include "../../vfio.h"
 
 /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
 static int qm_wait_dev_not_ready(struct hisi_qm *qm)
@@ -606,6 +607,18 @@ hisi_acc_check_int_state(struct hisi_acc_vf_core_device *hisi_acc_vdev)
 	}
 }
 
+static void hisi_acc_vf_migf_save(struct hisi_acc_vf_migration_file *dst_migf,
+	struct hisi_acc_vf_migration_file *src_migf)
+{
+	if (!dst_migf)
+		return;
+
+	dst_migf->disabled = false;
+	dst_migf->total_length = src_migf->total_length;
+	memcpy(&dst_migf->vf_data, &src_migf->vf_data,
+		    sizeof(struct acc_vf_data));
+}
+
 static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
 {
 	mutex_lock(&migf->lock);
@@ -618,12 +631,16 @@ static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
 static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device *hisi_acc_vdev)
 {
 	if (hisi_acc_vdev->resuming_migf) {
+		hisi_acc_vf_migf_save(hisi_acc_vdev->debug_migf,
+						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_vf_migf_save(hisi_acc_vdev->debug_migf,
+						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;
@@ -1156,6 +1173,7 @@ static int hisi_acc_vf_qm_init(struct hisi_acc_vf_core_device *hisi_acc_vdev)
 	if (!vf_qm->io_base)
 		return -EIO;
 
+	mutex_init(&hisi_acc_vdev->enable_mutex);
 	vf_qm->fun_type = QM_HW_VF;
 	vf_qm->pdev = vf_dev;
 	mutex_init(&vf_qm->mailbox_lock);
@@ -1306,6 +1324,176 @@ 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_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
+
+	if (!vdev->mig_ops || !migf) {
+		seq_printf(seq, "%s\n", "device does not support live migration!");
+		return -EINVAL;
+	}
+
+	/**
+	 * When the device is not opened, the io_base is not mapped.
+	 * The driver cannot perform device read and write operations.
+	 */
+	if (atomic_read(&hisi_acc_vdev->dev_opened) != DEV_OPEN) {
+		seq_printf(seq, "%s\n", "device not opened!");
+		return -EINVAL;
+	}
+
+	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->enable_mutex);
+	ret = hisi_acc_vf_debug_check(seq, vdev);
+	if (ret) {
+		mutex_unlock(&hisi_acc_vdev->enable_mutex);
+		return 0;
+	}
+
+	ret = qm_wait_dev_not_ready(vf_qm);
+	if (ret) {
+		mutex_unlock(&hisi_acc_vdev->enable_mutex);
+		seq_printf(seq, "%s\n", "VF device not ready!");
+		return 0;
+	}
+
+	value = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
+	mutex_unlock(&hisi_acc_vdev->enable_mutex);
+	seq_printf(seq, "%s:0x%llx\n", "mailbox cmd channel state is OK", value);
+
+	return 0;
+}
+
+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;
+
+	mutex_lock(&hisi_acc_vdev->enable_mutex);
+	ret = hisi_acc_vf_debug_check(seq, vdev);
+	if (ret) {
+		mutex_unlock(&hisi_acc_vdev->enable_mutex);
+		return 0;
+	}
+
+	ret = vf_qm_state_save(hisi_acc_vdev, migf);
+	if (ret) {
+		mutex_unlock(&hisi_acc_vdev->enable_mutex);
+		seq_printf(seq, "%s\n", "failed to save device data!");
+		return 0;
+	}
+	mutex_unlock(&hisi_acc_vdev->enable_mutex);
+	seq_printf(seq, "%s\n", "successful to save device data!");
+
+	return 0;
+}
+
+static int hisi_acc_vf_data_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);
+	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev->debug_migf;
+	size_t vf_data_sz = offsetofend(struct acc_vf_data, padding);
+
+	if (debug_migf && debug_migf->total_length)
+		seq_hex_dump(seq, "Mig Data:", DUMP_PREFIX_OFFSET, 16, 1,
+				(unsigned char *)&debug_migf->vf_data,
+				vf_data_sz, false);
+	else
+		seq_printf(seq, "%s\n", "device not migrated!");
+
+	return 0;
+}
+
+static int hisi_acc_vf_attr_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);
+	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev->debug_migf;
+
+	if (debug_migf && debug_migf->total_length) {
+		seq_printf(seq,
+			 "acc device:\n"
+			 "device  state: %d\n"
+			 "device  ready: %u\n"
+			 "data    valid: %d\n"
+			 "data     size: %lu\n",
+			 hisi_acc_vdev->mig_state,
+			 hisi_acc_vdev->vf_qm_state,
+			 debug_migf->disabled,
+			 debug_migf->total_length);
+	} else {
+		seq_printf(seq, "%s\n", "device not migrated!");
+	}
+
+	return 0;
+}
+
+static int 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())
+		return 0;
+
+	migf = kzalloc(sizeof(struct hisi_acc_vf_migration_file), GFP_KERNEL);
+	if (!migf)
+		return -ENOMEM;
+	hisi_acc_vdev->debug_migf = migf;
+
+	vfio_dev_migration = debugfs_lookup("migration", vdev->debug_root);
+	if (!vfio_dev_migration) {
+		kfree(migf);
+		dev_err(dev, "failed to lookup migration debugfs file!\n");
+		return -ENODEV;
+	}
+
+	vfio_hisi_acc = debugfs_create_dir("hisi_acc", vfio_dev_migration);
+	debugfs_create_devm_seqfile(dev, "data", vfio_hisi_acc,
+				  hisi_acc_vf_data_read);
+	debugfs_create_devm_seqfile(dev, "attr", vfio_hisi_acc,
+				  hisi_acc_vf_attr_read);
+	debugfs_create_devm_seqfile(dev, "cmd_state", vfio_hisi_acc,
+				  hisi_acc_vf_debug_cmd);
+	debugfs_create_devm_seqfile(dev, "save", vfio_hisi_acc,
+				  hisi_acc_vf_debug_save);
+
+	return 0;
+}
+
+static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device *hisi_acc_vdev)
+{
+	if (!debugfs_initialized())
+		return;
+
+	kfree(hisi_acc_vdev->debug_migf);
+}
+
 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);
@@ -1323,9 +1511,11 @@ static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev)
 			return ret;
 		}
 		hisi_acc_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
+		atomic_set(&hisi_acc_vdev->dev_opened, DEV_OPEN);
 	}
 
 	vfio_pci_core_finish_enable(vdev);
+
 	return 0;
 }
 
@@ -1334,7 +1524,10 @@ 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;
 
+	atomic_set(&hisi_acc_vdev->dev_opened, DEV_CLOSE);
+	mutex_lock(&hisi_acc_vdev->enable_mutex);
 	iounmap(vf_qm->io_base);
+	mutex_unlock(&hisi_acc_vdev->enable_mutex);
 	vfio_pci_core_close_device(core_vdev);
 }
 
@@ -1425,6 +1618,9 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device
 	ret = vfio_pci_core_register_device(&hisi_acc_vdev->core_device);
 	if (ret)
 		goto out_put_vdev;
+
+	if (ops == &hisi_acc_vfio_pci_migrn_ops)
+		hisi_acc_vfio_debug_init(hisi_acc_vdev);
 	return 0;
 
 out_put_vdev:
@@ -1437,6 +1633,7 @@ static void hisi_acc_vfio_pci_remove(struct pci_dev *pdev)
 	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);
 
 	vfio_pci_core_unregister_device(&hisi_acc_vdev->core_device);
+	hisi_acc_vf_debugfs_exit(hisi_acc_vdev);
 	vfio_put_device(&hisi_acc_vdev->core_device.vdev);
 }
 
diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
index dcabfeec6ca1..283bd8acdc42 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
@@ -49,6 +49,11 @@
 #define QM_EQC_DW0		0X8000
 #define QM_AEQC_DW0		0X8020
 
+enum acc_dev_state {
+	DEV_CLOSE = 0x0,
+	DEV_OPEN,
+};
+
 struct acc_vf_data {
 #define QM_MATCH_SIZE offsetofend(struct acc_vf_data, qm_rsv_state)
 	/* QM match information */
@@ -113,5 +118,11 @@ struct hisi_acc_vf_core_device {
 	spinlock_t reset_lock;
 	struct hisi_acc_vf_migration_file *resuming_migf;
 	struct hisi_acc_vf_migration_file *saving_migf;
+
+	/* To make sure the device is enabled */
+	struct mutex enable_mutex;
+	atomic_t dev_opened;
+	/* For debugfs */
+	struct hisi_acc_vf_migration_file *debug_migf;
 };
 #endif /* HISI_ACC_VFIO_PCI_H */
-- 
2.24.0

RE: [PATCH v2 2/3] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: liulongfang <liulongfang@huawei.com>
> Sent: Sunday, February 4, 2024 8:56 AM
> To: alex.williamson@redhat.com; jgg@nvidia.com; Shameerali Kolothum
> Thodi <shameerali.kolothum.thodi@huawei.com>; Jonathan Cameron
> <jonathan.cameron@huawei.com>
> Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org;
> linuxarm@openeuler.org; liulongfang <liulongfang@huawei.com>
> Subject: [PATCH v2 2/3] hisi_acc_vfio_pci: register debugfs for hisilicon
> migration driver
> 
> On the debugfs framework of VFIO, if the CONFIG_VFIO_DEBUGFS macro is
> enabled, the debug function is registered for the live migration driver
> of the HiSilicon accelerator device.
> 
> After registering the HiSilicon accelerator device on the debugfs
> framework of live migration of vfio, a directory file "hisi_acc"
> of debugfs is created, and then three debug function files are
> created in this directory:
> 
>    vfio
>     |
>     +---<dev_name1>
>     |    +---migration
>     |        +--state
>     |        +--hisi_acc
>     |            +--attr
>     |            +--data
>     |            +--save
>     |            +--cmd_state
>     |
>     +---<dev_name2>
>          +---migration
>              +--state
>              +--hisi_acc
>                  +--attr
>                  +--data
>                  +--save
>                  +--cmd_state
> 
> data file: used to get the migration data from the driver
> attr file: used to get device attributes parameters from the driver
> save file: used to read the data of the live migration device and save
> it to the driver.
> cmd_state: used to get the cmd channel state for the device.
> 
> Signed-off-by: Longfang Liu <liulongfang@huawei.com>
> ---
>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 197 ++++++++++++++++++
>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  11 +
>  2 files changed, 208 insertions(+)
> 
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> index 00a22a990eb8..e51bbb41c2b3 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> @@ -15,6 +15,7 @@
>  #include <linux/anon_inodes.h>
> 
>  #include "hisi_acc_vfio_pci.h"
> +#include "../../vfio.h"
> 
>  /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
>  static int qm_wait_dev_not_ready(struct hisi_qm *qm)
> @@ -606,6 +607,18 @@ hisi_acc_check_int_state(struct
> hisi_acc_vf_core_device *hisi_acc_vdev)
>  	}
>  }
> 
> +static void hisi_acc_vf_migf_save(struct hisi_acc_vf_migration_file
> *dst_migf,

Can we please rename this to indicate the debug, similar to other debugfs support
functions here, something like hisi_acc_vf_debug_migf_save()?

> +	struct hisi_acc_vf_migration_file *src_migf)
> +{
> +	if (!dst_migf)
> +		return;
> +
> +	dst_migf->disabled = false;

Is this set to true anywhere for debugfs migf ?

> +	dst_migf->total_length = src_migf->total_length;
> +	memcpy(&dst_migf->vf_data, &src_migf->vf_data,
> +		    sizeof(struct acc_vf_data));
> +}
> +
>  static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
>  {
>  	mutex_lock(&migf->lock);
> @@ -618,12 +631,16 @@ static void hisi_acc_vf_disable_fd(struct
> hisi_acc_vf_migration_file *migf)
>  static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device
> *hisi_acc_vdev)
>  {
>  	if (hisi_acc_vdev->resuming_migf) {
> +		hisi_acc_vf_migf_save(hisi_acc_vdev->debug_migf,
> +						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_vf_migf_save(hisi_acc_vdev->debug_migf,
> +						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;
> @@ -1156,6 +1173,7 @@ static int hisi_acc_vf_qm_init(struct
> hisi_acc_vf_core_device *hisi_acc_vdev)
>  	if (!vf_qm->io_base)
>  		return -EIO;
> 
> +	mutex_init(&hisi_acc_vdev->enable_mutex);
>  	vf_qm->fun_type = QM_HW_VF;
>  	vf_qm->pdev = vf_dev;
>  	mutex_init(&vf_qm->mailbox_lock);
> @@ -1306,6 +1324,176 @@ 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_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
> +
> +	if (!vdev->mig_ops || !migf) {
> +		seq_printf(seq, "%s\n", "device does not support live
> migration!");
> +		return -EINVAL;
> +	}
> +
> +	/**
> +	 * When the device is not opened, the io_base is not mapped.
> +	 * The driver cannot perform device read and write operations.
> +	 */
> +	if (atomic_read(&hisi_acc_vdev->dev_opened) != DEV_OPEN) {
> +		seq_printf(seq, "%s\n", "device not opened!");
> +		return -EINVAL;
> +	}
> +
> +	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->enable_mutex);
> +	ret = hisi_acc_vf_debug_check(seq, vdev);
> +	if (ret) {
> +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
> +		return 0;
> +	}
> +
> +	ret = qm_wait_dev_not_ready(vf_qm);
> +	if (ret) {
> +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
> +		seq_printf(seq, "%s\n", "VF device not ready!");
> +		return 0;
> +	}
> +
> +	value = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
> +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
> +	seq_printf(seq, "%s:0x%llx\n", "mailbox cmd channel state is OK",
> value);
> +
> +	return 0;
> +}
> +
> +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;
> +
> +	mutex_lock(&hisi_acc_vdev->enable_mutex);
> +	ret = hisi_acc_vf_debug_check(seq, vdev);
> +	if (ret) {
> +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
> +		return 0;
> +	}
> +
> +	ret = vf_qm_state_save(hisi_acc_vdev, migf);

Are you sure this will not interfere with the core migration APIs as we are not
holding the state_mutex?. I think Alex also raised a similar concern previously. 
Applies to other debugfs interfaces here as well. Please check.


> +	if (ret) {
> +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
> +		seq_printf(seq, "%s\n", "failed to save device data!");
> +		return 0;
> +	}
> +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
> +	seq_printf(seq, "%s\n", "successful to save device data!");
> +
> +	return 0;
> +}
> +
> +static int hisi_acc_vf_data_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);
> +	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev-
> >debug_migf;
> +	size_t vf_data_sz = offsetofend(struct acc_vf_data, padding);
> +
> +	if (debug_migf && debug_migf->total_length)
> +		seq_hex_dump(seq, "Mig Data:", DUMP_PREFIX_OFFSET, 16,
> 1,
> +				(unsigned char *)&debug_migf->vf_data,
> +				vf_data_sz, false);
> +	else
> +		seq_printf(seq, "%s\n", "device not migrated!");
> +
> +	return 0;
> +}
> +
> +static int hisi_acc_vf_attr_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);
> +	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev-
> >debug_migf;
> +
> +	if (debug_migf && debug_migf->total_length) {
> +		seq_printf(seq,
> +			 "acc device:\n"
> +			 "device  state: %d\n"
> +			 "device  ready: %u\n"
> +			 "data    valid: %d\n"
> +			 "data     size: %lu\n",
> +			 hisi_acc_vdev->mig_state,
> +			 hisi_acc_vdev->vf_qm_state,
> +			 debug_migf->disabled,
> +			 debug_migf->total_length);
> +	} else {
> +		seq_printf(seq, "%s\n", "device not migrated!");
> +	}
> +
> +	return 0;
> +}
> +
> +static int 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())
> +		return 0;
> +
> +	migf = kzalloc(sizeof(struct hisi_acc_vf_migration_file), GFP_KERNEL);
> +	if (!migf)
> +		return -ENOMEM;
> +	hisi_acc_vdev->debug_migf = migf;
> +
> +	vfio_dev_migration = debugfs_lookup("migration", vdev-
> >debug_root);
> +	if (!vfio_dev_migration) {
> +		kfree(migf);
> +		dev_err(dev, "failed to lookup migration debugfs file!\n");
> +		return -ENODEV;
> +	}
> +
> +	vfio_hisi_acc = debugfs_create_dir("hisi_acc", vfio_dev_migration);
> +	debugfs_create_devm_seqfile(dev, "data", vfio_hisi_acc,
> +				  hisi_acc_vf_data_read);
> +	debugfs_create_devm_seqfile(dev, "attr", vfio_hisi_acc,
> +				  hisi_acc_vf_attr_read);
> +	debugfs_create_devm_seqfile(dev, "cmd_state", vfio_hisi_acc,
> +				  hisi_acc_vf_debug_cmd);
> +	debugfs_create_devm_seqfile(dev, "save", vfio_hisi_acc,
> +				  hisi_acc_vf_debug_save);
> +
> +	return 0;
> +}
> +
> +static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device
> *hisi_acc_vdev)
> +{
> +	if (!debugfs_initialized())
> +		return;
> +
> +	kfree(hisi_acc_vdev->debug_migf);
> +}
> +
>  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);
> @@ -1323,9 +1511,11 @@ static int hisi_acc_vfio_pci_open_device(struct
> vfio_device *core_vdev)
>  			return ret;
>  		}
>  		hisi_acc_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
> +		atomic_set(&hisi_acc_vdev->dev_opened, DEV_OPEN);
>  	}
> 
>  	vfio_pci_core_finish_enable(vdev);
> +
>  	return 0;
>  }
> 
> @@ -1334,7 +1524,10 @@ 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;
> 
> +	atomic_set(&hisi_acc_vdev->dev_opened, DEV_CLOSE);
> +	mutex_lock(&hisi_acc_vdev->enable_mutex);
>  	iounmap(vf_qm->io_base);
> +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
>  	vfio_pci_core_close_device(core_vdev);
>  }
> 
> @@ -1425,6 +1618,9 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev
> *pdev, const struct pci_device
>  	ret = vfio_pci_core_register_device(&hisi_acc_vdev->core_device);
>  	if (ret)
>  		goto out_put_vdev;
> +
> +	if (ops == &hisi_acc_vfio_pci_migrn_ops)
> +		hisi_acc_vfio_debug_init(hisi_acc_vdev);
>  	return 0;
> 
>  out_put_vdev:
> @@ -1437,6 +1633,7 @@ static void hisi_acc_vfio_pci_remove(struct pci_dev
> *pdev)
>  	struct hisi_acc_vf_core_device *hisi_acc_vdev =
> hisi_acc_drvdata(pdev);
> 
>  	vfio_pci_core_unregister_device(&hisi_acc_vdev->core_device);
> +	hisi_acc_vf_debugfs_exit(hisi_acc_vdev);
>  	vfio_put_device(&hisi_acc_vdev->core_device.vdev);
>  }
> 
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> index dcabfeec6ca1..283bd8acdc42 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> @@ -49,6 +49,11 @@
>  #define QM_EQC_DW0		0X8000
>  #define QM_AEQC_DW0		0X8020
> 
> +enum acc_dev_state {
> +	DEV_CLOSE = 0x0,
> +	DEV_OPEN,
> +};

Do we really need this enum as you can directly use 0 or 1?

Thanks,
Shameer

> +
>  struct acc_vf_data {
>  #define QM_MATCH_SIZE offsetofend(struct acc_vf_data, qm_rsv_state)
>  	/* QM match information */
> @@ -113,5 +118,11 @@ struct hisi_acc_vf_core_device {
>  	spinlock_t reset_lock;
>  	struct hisi_acc_vf_migration_file *resuming_migf;
>  	struct hisi_acc_vf_migration_file *saving_migf;
> +
> +	/* To make sure the device is enabled */
> +	struct mutex enable_mutex;
> +	atomic_t dev_opened;
> +	/* For debugfs */
> +	struct hisi_acc_vf_migration_file *debug_migf;
>  };
>  #endif /* HISI_ACC_VFIO_PCI_H */
> --
> 2.24.0

Re: [PATCH v2 2/3] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

[Alex Williamson]

On Mon, 5 Feb 2024 08:52:06 +0000
Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> wrote:

> > -----Original Message-----
> > From: liulongfang <liulongfang@huawei.com>
> > Sent: Sunday, February 4, 2024 8:56 AM
> > To: alex.williamson@redhat.com; jgg@nvidia.com; Shameerali Kolothum
> > Thodi <shameerali.kolothum.thodi@huawei.com>; Jonathan Cameron
> > <jonathan.cameron@huawei.com>
> > Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org;
> > linuxarm@openeuler.org; liulongfang <liulongfang@huawei.com>
> > Subject: [PATCH v2 2/3] hisi_acc_vfio_pci: register debugfs for hisilicon
> > migration driver
> > 
> > On the debugfs framework of VFIO, if the CONFIG_VFIO_DEBUGFS macro is
> > enabled, the debug function is registered for the live migration driver
> > of the HiSilicon accelerator device.
> > 
> > After registering the HiSilicon accelerator device on the debugfs
> > framework of live migration of vfio, a directory file "hisi_acc"
> > of debugfs is created, and then three debug function files are
> > created in this directory:
> > 
> >    vfio
> >     |
> >     +---<dev_name1>
> >     |    +---migration
> >     |        +--state
> >     |        +--hisi_acc
> >     |            +--attr
> >     |            +--data
> >     |            +--save
> >     |            +--cmd_state
> >     |
> >     +---<dev_name2>
> >          +---migration
> >              +--state
> >              +--hisi_acc
> >                  +--attr
> >                  +--data
> >                  +--save
> >                  +--cmd_state
> > 
> > data file: used to get the migration data from the driver
> > attr file: used to get device attributes parameters from the driver
> > save file: used to read the data of the live migration device and save
> > it to the driver.
> > cmd_state: used to get the cmd channel state for the device.
> > 
> > Signed-off-by: Longfang Liu <liulongfang@huawei.com>
> > ---
> >  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 197 ++++++++++++++++++
> >  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  11 +
> >  2 files changed, 208 insertions(+)
> > 
> > diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> > b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> > index 00a22a990eb8..e51bbb41c2b3 100644
> > --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> > +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> > @@ -15,6 +15,7 @@
> >  #include <linux/anon_inodes.h>
> > 
> >  #include "hisi_acc_vfio_pci.h"
> > +#include "../../vfio.h"
> > 
> >  /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
> >  static int qm_wait_dev_not_ready(struct hisi_qm *qm)
> > @@ -606,6 +607,18 @@ hisi_acc_check_int_state(struct
> > hisi_acc_vf_core_device *hisi_acc_vdev)
> >  	}
> >  }
> > 
> > +static void hisi_acc_vf_migf_save(struct hisi_acc_vf_migration_file
> > *dst_migf,  
> 
> Can we please rename this to indicate the debug, similar to other debugfs support
> functions here, something like hisi_acc_vf_debug_migf_save()?
> 
> > +	struct hisi_acc_vf_migration_file *src_migf)
> > +{
> > +	if (!dst_migf)
> > +		return;
> > +
> > +	dst_migf->disabled = false;  
> 
> Is this set to true anywhere for debugfs migf ?
> 
> > +	dst_migf->total_length = src_migf->total_length;
> > +	memcpy(&dst_migf->vf_data, &src_migf->vf_data,
> > +		    sizeof(struct acc_vf_data));
> > +}
> > +
> >  static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
> >  {
> >  	mutex_lock(&migf->lock);
> > @@ -618,12 +631,16 @@ static void hisi_acc_vf_disable_fd(struct
> > hisi_acc_vf_migration_file *migf)
> >  static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device
> > *hisi_acc_vdev)
> >  {
> >  	if (hisi_acc_vdev->resuming_migf) {
> > +		hisi_acc_vf_migf_save(hisi_acc_vdev->debug_migf,
> > +						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_vf_migf_save(hisi_acc_vdev->debug_migf,
> > +						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;
> > @@ -1156,6 +1173,7 @@ static int hisi_acc_vf_qm_init(struct
> > hisi_acc_vf_core_device *hisi_acc_vdev)
> >  	if (!vf_qm->io_base)
> >  		return -EIO;
> > 
> > +	mutex_init(&hisi_acc_vdev->enable_mutex);
> >  	vf_qm->fun_type = QM_HW_VF;
> >  	vf_qm->pdev = vf_dev;
> >  	mutex_init(&vf_qm->mailbox_lock);
> > @@ -1306,6 +1324,176 @@ 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_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
> > +
> > +	if (!vdev->mig_ops || !migf) {
> > +		seq_printf(seq, "%s\n", "device does not support live
> > migration!");
> > +		return -EINVAL;
> > +	}
> > +
> > +	/**
> > +	 * When the device is not opened, the io_base is not mapped.
> > +	 * The driver cannot perform device read and write operations.
> > +	 */
> > +	if (atomic_read(&hisi_acc_vdev->dev_opened) != DEV_OPEN) {
> > +		seq_printf(seq, "%s\n", "device not opened!");
> > +		return -EINVAL;
> > +	}
> > +
> > +	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->enable_mutex);
> > +	ret = hisi_acc_vf_debug_check(seq, vdev);
> > +	if (ret) {
> > +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
> > +		return 0;
> > +	}
> > +
> > +	ret = qm_wait_dev_not_ready(vf_qm);
> > +	if (ret) {
> > +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
> > +		seq_printf(seq, "%s\n", "VF device not ready!");
> > +		return 0;
> > +	}
> > +
> > +	value = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
> > +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
> > +	seq_printf(seq, "%s:0x%llx\n", "mailbox cmd channel state is OK",
> > value);
> > +
> > +	return 0;
> > +}
> > +
> > +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;
> > +
> > +	mutex_lock(&hisi_acc_vdev->enable_mutex);
> > +	ret = hisi_acc_vf_debug_check(seq, vdev);
> > +	if (ret) {
> > +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
> > +		return 0;
> > +	}
> > +
> > +	ret = vf_qm_state_save(hisi_acc_vdev, migf);  
> 
> Are you sure this will not interfere with the core migration APIs as we are not
> holding the state_mutex?. I think Alex also raised a similar concern previously. 
> Applies to other debugfs interfaces here as well. Please check.

And if it does not need to be serialized, why are we using a mutex
rather than a semaphore?  For example if it can run concurrently with
the core migration APIs, it should run concurrently with itself and
debugfs could take read-locks.  Also as implemented here the atomic is
not only uninitialized, but pretty pointless anyway.  dev_opened could
be a bool protected within the mutex/semaphore, which would at least
make it sane that the lock protects the bool since it clearly doesn't
protect io_base.  Thanks,

Alex

> > +	if (ret) {
> > +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
> > +		seq_printf(seq, "%s\n", "failed to save device data!");
> > +		return 0;
> > +	}
> > +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
> > +	seq_printf(seq, "%s\n", "successful to save device data!");
> > +
> > +	return 0;
> > +}
> > +
> > +static int hisi_acc_vf_data_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);
> > +	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev-  
> > >debug_migf;  
> > +	size_t vf_data_sz = offsetofend(struct acc_vf_data, padding);
> > +
> > +	if (debug_migf && debug_migf->total_length)
> > +		seq_hex_dump(seq, "Mig Data:", DUMP_PREFIX_OFFSET, 16,
> > 1,
> > +				(unsigned char *)&debug_migf->vf_data,
> > +				vf_data_sz, false);
> > +	else
> > +		seq_printf(seq, "%s\n", "device not migrated!");
> > +
> > +	return 0;
> > +}
> > +
> > +static int hisi_acc_vf_attr_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);
> > +	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev-  
> > >debug_migf;  
> > +
> > +	if (debug_migf && debug_migf->total_length) {
> > +		seq_printf(seq,
> > +			 "acc device:\n"
> > +			 "device  state: %d\n"
> > +			 "device  ready: %u\n"
> > +			 "data    valid: %d\n"
> > +			 "data     size: %lu\n",
> > +			 hisi_acc_vdev->mig_state,
> > +			 hisi_acc_vdev->vf_qm_state,
> > +			 debug_migf->disabled,
> > +			 debug_migf->total_length);
> > +	} else {
> > +		seq_printf(seq, "%s\n", "device not migrated!");
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int 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())
> > +		return 0;
> > +
> > +	migf = kzalloc(sizeof(struct hisi_acc_vf_migration_file), GFP_KERNEL);
> > +	if (!migf)
> > +		return -ENOMEM;
> > +	hisi_acc_vdev->debug_migf = migf;
> > +
> > +	vfio_dev_migration = debugfs_lookup("migration", vdev-  
> > >debug_root);  
> > +	if (!vfio_dev_migration) {
> > +		kfree(migf);
> > +		dev_err(dev, "failed to lookup migration debugfs file!\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	vfio_hisi_acc = debugfs_create_dir("hisi_acc", vfio_dev_migration);
> > +	debugfs_create_devm_seqfile(dev, "data", vfio_hisi_acc,
> > +				  hisi_acc_vf_data_read);
> > +	debugfs_create_devm_seqfile(dev, "attr", vfio_hisi_acc,
> > +				  hisi_acc_vf_attr_read);
> > +	debugfs_create_devm_seqfile(dev, "cmd_state", vfio_hisi_acc,
> > +				  hisi_acc_vf_debug_cmd);
> > +	debugfs_create_devm_seqfile(dev, "save", vfio_hisi_acc,
> > +				  hisi_acc_vf_debug_save);
> > +
> > +	return 0;
> > +}
> > +
> > +static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device
> > *hisi_acc_vdev)
> > +{
> > +	if (!debugfs_initialized())
> > +		return;
> > +
> > +	kfree(hisi_acc_vdev->debug_migf);
> > +}
> > +
> >  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);
> > @@ -1323,9 +1511,11 @@ static int hisi_acc_vfio_pci_open_device(struct
> > vfio_device *core_vdev)
> >  			return ret;
> >  		}
> >  		hisi_acc_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
> > +		atomic_set(&hisi_acc_vdev->dev_opened, DEV_OPEN);
> >  	}
> > 
> >  	vfio_pci_core_finish_enable(vdev);
> > +
> >  	return 0;
> >  }
> > 
> > @@ -1334,7 +1524,10 @@ 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;
> > 
> > +	atomic_set(&hisi_acc_vdev->dev_opened, DEV_CLOSE);
> > +	mutex_lock(&hisi_acc_vdev->enable_mutex);
> >  	iounmap(vf_qm->io_base);
> > +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
> >  	vfio_pci_core_close_device(core_vdev);
> >  }
> > 
> > @@ -1425,6 +1618,9 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev
> > *pdev, const struct pci_device
> >  	ret = vfio_pci_core_register_device(&hisi_acc_vdev->core_device);
> >  	if (ret)
> >  		goto out_put_vdev;
> > +
> > +	if (ops == &hisi_acc_vfio_pci_migrn_ops)
> > +		hisi_acc_vfio_debug_init(hisi_acc_vdev);
> >  	return 0;
> > 
> >  out_put_vdev:
> > @@ -1437,6 +1633,7 @@ static void hisi_acc_vfio_pci_remove(struct pci_dev
> > *pdev)
> >  	struct hisi_acc_vf_core_device *hisi_acc_vdev =
> > hisi_acc_drvdata(pdev);
> > 
> >  	vfio_pci_core_unregister_device(&hisi_acc_vdev->core_device);
> > +	hisi_acc_vf_debugfs_exit(hisi_acc_vdev);
> >  	vfio_put_device(&hisi_acc_vdev->core_device.vdev);
> >  }
> > 
> > diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> > b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> > index dcabfeec6ca1..283bd8acdc42 100644
> > --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> > +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> > @@ -49,6 +49,11 @@
> >  #define QM_EQC_DW0		0X8000
> >  #define QM_AEQC_DW0		0X8020
> > 
> > +enum acc_dev_state {
> > +	DEV_CLOSE = 0x0,
> > +	DEV_OPEN,
> > +};  
> 
> Do we really need this enum as you can directly use 0 or 1?
> 
> Thanks,
> Shameer
> 
> > +
> >  struct acc_vf_data {
> >  #define QM_MATCH_SIZE offsetofend(struct acc_vf_data, qm_rsv_state)
> >  	/* QM match information */
> > @@ -113,5 +118,11 @@ struct hisi_acc_vf_core_device {
> >  	spinlock_t reset_lock;
> >  	struct hisi_acc_vf_migration_file *resuming_migf;
> >  	struct hisi_acc_vf_migration_file *saving_migf;
> > +
> > +	/* To make sure the device is enabled */
> > +	struct mutex enable_mutex;
> > +	atomic_t dev_opened;
> > +	/* For debugfs */
> > +	struct hisi_acc_vf_migration_file *debug_migf;
> >  };
> >  #endif /* HISI_ACC_VFIO_PCI_H */
> > --
> > 2.24.0  
> 
> 

Re: [PATCH v2 2/3] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

[liulongfang]

on 2024/2/5 16:52, Shameerali Kolothum Thodi wrote:
> 
> 
>> -----Original Message-----
>> From: liulongfang <liulongfang@huawei.com>
>> Sent: Sunday, February 4, 2024 8:56 AM
>> To: alex.williamson@redhat.com; jgg@nvidia.com; Shameerali Kolothum
>> Thodi <shameerali.kolothum.thodi@huawei.com>; Jonathan Cameron
>> <jonathan.cameron@huawei.com>
>> Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org;
>> linuxarm@openeuler.org; liulongfang <liulongfang@huawei.com>
>> Subject: [PATCH v2 2/3] hisi_acc_vfio_pci: register debugfs for hisilicon
>> migration driver
>>
>> On the debugfs framework of VFIO, if the CONFIG_VFIO_DEBUGFS macro is
>> enabled, the debug function is registered for the live migration driver
>> of the HiSilicon accelerator device.
>>
>> After registering the HiSilicon accelerator device on the debugfs
>> framework of live migration of vfio, a directory file "hisi_acc"
>> of debugfs is created, and then three debug function files are
>> created in this directory:
>>
>>    vfio
>>     |
>>     +---<dev_name1>
>>     |    +---migration
>>     |        +--state
>>     |        +--hisi_acc
>>     |            +--attr
>>     |            +--data
>>     |            +--save
>>     |            +--cmd_state
>>     |
>>     +---<dev_name2>
>>          +---migration
>>              +--state
>>              +--hisi_acc
>>                  +--attr
>>                  +--data
>>                  +--save
>>                  +--cmd_state
>>
>> data file: used to get the migration data from the driver
>> attr file: used to get device attributes parameters from the driver
>> save file: used to read the data of the live migration device and save
>> it to the driver.
>> cmd_state: used to get the cmd channel state for the device.
>>
>> Signed-off-by: Longfang Liu <liulongfang@huawei.com>
>> ---
>>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 197 ++++++++++++++++++
>>  .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  11 +
>>  2 files changed, 208 insertions(+)
>>
>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> index 00a22a990eb8..e51bbb41c2b3 100644
>> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> @@ -15,6 +15,7 @@
>>  #include <linux/anon_inodes.h>
>>
>>  #include "hisi_acc_vfio_pci.h"
>> +#include "../../vfio.h"
>>
>>  /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
>>  static int qm_wait_dev_not_ready(struct hisi_qm *qm)
>> @@ -606,6 +607,18 @@ hisi_acc_check_int_state(struct
>> hisi_acc_vf_core_device *hisi_acc_vdev)
>>  	}
>>  }
>>
>> +static void hisi_acc_vf_migf_save(struct hisi_acc_vf_migration_file
>> *dst_migf,
> 
> Can we please rename this to indicate the debug, similar to other debugfs support
> functions here, something like hisi_acc_vf_debug_migf_save()?
>

This function is not exclusive to debugfs and does not need to be renamed.

>> +	struct hisi_acc_vf_migration_file *src_migf)
>> +{
>> +	if (!dst_migf)
>> +		return;
>> +
>> +	dst_migf->disabled = false;
> 
> Is this set to true anywhere for debugfs migf ?
>

I verified this assignment operation and there is no problem.

>> +	dst_migf->total_length = src_migf->total_length;
>> +	memcpy(&dst_migf->vf_data, &src_migf->vf_data,
>> +		    sizeof(struct acc_vf_data));
>> +}
>> +
>>  static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
>>  {
>>  	mutex_lock(&migf->lock);
>> @@ -618,12 +631,16 @@ static void hisi_acc_vf_disable_fd(struct
>> hisi_acc_vf_migration_file *migf)
>>  static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device
>> *hisi_acc_vdev)
>>  {
>>  	if (hisi_acc_vdev->resuming_migf) {
>> +		hisi_acc_vf_migf_save(hisi_acc_vdev->debug_migf,
>> +						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_vf_migf_save(hisi_acc_vdev->debug_migf,
>> +						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;
>> @@ -1156,6 +1173,7 @@ static int hisi_acc_vf_qm_init(struct
>> hisi_acc_vf_core_device *hisi_acc_vdev)
>>  	if (!vf_qm->io_base)
>>  		return -EIO;
>>
>> +	mutex_init(&hisi_acc_vdev->enable_mutex);
>>  	vf_qm->fun_type = QM_HW_VF;
>>  	vf_qm->pdev = vf_dev;
>>  	mutex_init(&vf_qm->mailbox_lock);
>> @@ -1306,6 +1324,176 @@ 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_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
>> +
>> +	if (!vdev->mig_ops || !migf) {
>> +		seq_printf(seq, "%s\n", "device does not support live
>> migration!");
>> +		return -EINVAL;
>> +	}
>> +
>> +	/**
>> +	 * When the device is not opened, the io_base is not mapped.
>> +	 * The driver cannot perform device read and write operations.
>> +	 */
>> +	if (atomic_read(&hisi_acc_vdev->dev_opened) != DEV_OPEN) {
>> +		seq_printf(seq, "%s\n", "device not opened!");
>> +		return -EINVAL;
>> +	}
>> +
>> +	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->enable_mutex);
>> +	ret = hisi_acc_vf_debug_check(seq, vdev);
>> +	if (ret) {
>> +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
>> +		return 0;
>> +	}
>> +
>> +	ret = qm_wait_dev_not_ready(vf_qm);
>> +	if (ret) {
>> +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
>> +		seq_printf(seq, "%s\n", "VF device not ready!");
>> +		return 0;
>> +	}
>> +
>> +	value = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
>> +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
>> +	seq_printf(seq, "%s:0x%llx\n", "mailbox cmd channel state is OK",
>> value);
>> +
>> +	return 0;
>> +}
>> +
>> +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;
>> +
>> +	mutex_lock(&hisi_acc_vdev->enable_mutex);
>> +	ret = hisi_acc_vf_debug_check(seq, vdev);
>> +	if (ret) {
>> +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
>> +		return 0;
>> +	}
>> +
>> +	ret = vf_qm_state_save(hisi_acc_vdev, migf);
> 
> Are you sure this will not interfere with the core migration APIs as we are not
> holding the state_mutex?. I think Alex also raised a similar concern previously. 

Yes, it is possible that the qemu live migration operation will be executed at the same time
as the debugfs operation.
At this time, the operation of debugfs needs to be disabled.

> Applies to other debugfs interfaces here as well. Please check.
> 
> 
>> +	if (ret) {
>> +		mutex_unlock(&hisi_acc_vdev->enable_mutex);
>> +		seq_printf(seq, "%s\n", "failed to save device data!");
>> +		return 0;
>> +	}
>> +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
>> +	seq_printf(seq, "%s\n", "successful to save device data!");
>> +
>> +	return 0;
>> +}
>> +
>> +static int hisi_acc_vf_data_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);
>> +	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev-
>>> debug_migf;
>> +	size_t vf_data_sz = offsetofend(struct acc_vf_data, padding);
>> +
>> +	if (debug_migf && debug_migf->total_length)
>> +		seq_hex_dump(seq, "Mig Data:", DUMP_PREFIX_OFFSET, 16,
>> 1,
>> +				(unsigned char *)&debug_migf->vf_data,
>> +				vf_data_sz, false);
>> +	else
>> +		seq_printf(seq, "%s\n", "device not migrated!");
>> +
>> +	return 0;
>> +}
>> +
>> +static int hisi_acc_vf_attr_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);
>> +	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev-
>>> debug_migf;
>> +
>> +	if (debug_migf && debug_migf->total_length) {
>> +		seq_printf(seq,
>> +			 "acc device:\n"
>> +			 "device  state: %d\n"
>> +			 "device  ready: %u\n"
>> +			 "data    valid: %d\n"
>> +			 "data     size: %lu\n",
>> +			 hisi_acc_vdev->mig_state,
>> +			 hisi_acc_vdev->vf_qm_state,
>> +			 debug_migf->disabled,
>> +			 debug_migf->total_length);
>> +	} else {
>> +		seq_printf(seq, "%s\n", "device not migrated!");
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int 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())
>> +		return 0;
>> +
>> +	migf = kzalloc(sizeof(struct hisi_acc_vf_migration_file), GFP_KERNEL);
>> +	if (!migf)
>> +		return -ENOMEM;
>> +	hisi_acc_vdev->debug_migf = migf;
>> +
>> +	vfio_dev_migration = debugfs_lookup("migration", vdev-
>>> debug_root);
>> +	if (!vfio_dev_migration) {
>> +		kfree(migf);
>> +		dev_err(dev, "failed to lookup migration debugfs file!\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	vfio_hisi_acc = debugfs_create_dir("hisi_acc", vfio_dev_migration);
>> +	debugfs_create_devm_seqfile(dev, "data", vfio_hisi_acc,
>> +				  hisi_acc_vf_data_read);
>> +	debugfs_create_devm_seqfile(dev, "attr", vfio_hisi_acc,
>> +				  hisi_acc_vf_attr_read);
>> +	debugfs_create_devm_seqfile(dev, "cmd_state", vfio_hisi_acc,
>> +				  hisi_acc_vf_debug_cmd);
>> +	debugfs_create_devm_seqfile(dev, "save", vfio_hisi_acc,
>> +				  hisi_acc_vf_debug_save);
>> +
>> +	return 0;
>> +}
>> +
>> +static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device
>> *hisi_acc_vdev)
>> +{
>> +	if (!debugfs_initialized())
>> +		return;
>> +
>> +	kfree(hisi_acc_vdev->debug_migf);
>> +}
>> +
>>  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);
>> @@ -1323,9 +1511,11 @@ static int hisi_acc_vfio_pci_open_device(struct
>> vfio_device *core_vdev)
>>  			return ret;
>>  		}
>>  		hisi_acc_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
>> +		atomic_set(&hisi_acc_vdev->dev_opened, DEV_OPEN);
>>  	}
>>
>>  	vfio_pci_core_finish_enable(vdev);
>> +
>>  	return 0;
>>  }
>>
>> @@ -1334,7 +1524,10 @@ 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;
>>
>> +	atomic_set(&hisi_acc_vdev->dev_opened, DEV_CLOSE);
>> +	mutex_lock(&hisi_acc_vdev->enable_mutex);
>>  	iounmap(vf_qm->io_base);
>> +	mutex_unlock(&hisi_acc_vdev->enable_mutex);
>>  	vfio_pci_core_close_device(core_vdev);
>>  }
>>
>> @@ -1425,6 +1618,9 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev
>> *pdev, const struct pci_device
>>  	ret = vfio_pci_core_register_device(&hisi_acc_vdev->core_device);
>>  	if (ret)
>>  		goto out_put_vdev;
>> +
>> +	if (ops == &hisi_acc_vfio_pci_migrn_ops)
>> +		hisi_acc_vfio_debug_init(hisi_acc_vdev);
>>  	return 0;
>>
>>  out_put_vdev:
>> @@ -1437,6 +1633,7 @@ static void hisi_acc_vfio_pci_remove(struct pci_dev
>> *pdev)
>>  	struct hisi_acc_vf_core_device *hisi_acc_vdev =
>> hisi_acc_drvdata(pdev);
>>
>>  	vfio_pci_core_unregister_device(&hisi_acc_vdev->core_device);
>> +	hisi_acc_vf_debugfs_exit(hisi_acc_vdev);
>>  	vfio_put_device(&hisi_acc_vdev->core_device.vdev);
>>  }
>>
>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
>> b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
>> index dcabfeec6ca1..283bd8acdc42 100644
>> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
>> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
>> @@ -49,6 +49,11 @@
>>  #define QM_EQC_DW0		0X8000
>>  #define QM_AEQC_DW0		0X8020
>>
>> +enum acc_dev_state {
>> +	DEV_CLOSE = 0x0,
>> +	DEV_OPEN,
>> +};
> 
> Do we really need this enum as you can directly use 0 or 1?
>

Use enumeration types to make it easier to understand the functionality of the code.

Thanks,
Longfang.

> Thanks,
> Shameer
> 
>> +
>>  struct acc_vf_data {
>>  #define QM_MATCH_SIZE offsetofend(struct acc_vf_data, qm_rsv_state)
>>  	/* QM match information */
>> @@ -113,5 +118,11 @@ struct hisi_acc_vf_core_device {
>>  	spinlock_t reset_lock;
>>  	struct hisi_acc_vf_migration_file *resuming_migf;
>>  	struct hisi_acc_vf_migration_file *saving_migf;
>> +
>> +	/* To make sure the device is enabled */
>> +	struct mutex enable_mutex;
>> +	atomic_t dev_opened;
>> +	/* For debugfs */
>> +	struct hisi_acc_vf_migration_file *debug_migf;
>>  };
>>  #endif /* HISI_ACC_VFIO_PCI_H */
>> --
>> 2.24.0
> 
> .
> 

[PATCH v2 3/3] Documentation: add debugfs description for hisi migration

[Longfang Liu]

Add a debugfs document description file to help users understand
how to use the hisilicon accelerator live migration driver's
debugfs.

Update the file paths that need to be maintained in MAINTAINERS

Signed-off-by: Longfang Liu <liulongfang@huawei.com>
---
 .../ABI/testing/debugfs-hisi-migration        | 34 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 35 insertions(+)
 create mode 100644 Documentation/ABI/testing/debugfs-hisi-migration

diff --git a/Documentation/ABI/testing/debugfs-hisi-migration b/Documentation/ABI/testing/debugfs-hisi-migration
new file mode 100644
index 000000000000..d61255c3bcd9
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-hisi-migration
@@ -0,0 +1,34 @@
+What:		/sys/kernel/debug/vfio/<device>/migration/hisi_acc/data
+Date:		Feb 2024
+KernelVersion:  6.8
+Contact:	Longfang Liu <liulongfang@huawei.com>
+Description:	Read the live migration data of the vfio device.
+		These data include device status data, queue configuration
+		data and some task configuration data.
+		The output format of the data is defined by the live
+		migration driver.
+
+What:		/sys/kernel/debug/vfio/<device>/migration/hisi_acc/attr
+Date:		Feb 2024
+KernelVersion:  6.8
+Contact:	Longfang Liu <liulongfang@huawei.com>
+Description:	Read the live migration attributes of the vfio device.
+		it include device status attributes and data length attributes
+		The output format of the attributes is defined by the live
+		migration driver.
+
+What:		/sys/kernel/debug/vfio/<device>/migration/hisi_acc/cmd_state
+Date:		Feb 2024
+KernelVersion:  6.8
+Contact:	Longfang Liu <liulongfang@huawei.com>
+Description:	Used to obtain the device command sending and receiving
+		channel status. If successful, returns the command value.
+		If failed, return error log.
+
+What:		/sys/kernel/debug/vfio/<device>/migration/hisi_acc/save
+Date:		Feb 2024
+KernelVersion:  6.8
+Contact:	Longfang Liu <liulongfang@huawei.com>
+Description:	Trigger the Hisilicon accelerator device to perform
+		the state saving operation of live migration through the read
+		operation, and output the operation log results.
diff --git a/MAINTAINERS b/MAINTAINERS
index 20f8e9872deb..115d43d307e8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22856,6 +22856,7 @@ M:	Longfang Liu <liulongfang@huawei.com>
 M:	Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
 L:	kvm@vger.kernel.org
 S:	Maintained
+F:	Documentation/ABI/testing/debugfs-hisi-migration
 F:	drivers/vfio/pci/hisilicon/
 
 VFIO MEDIATED DEVICE DRIVERS
-- 
2.24.0