2022-12-02 10:03:04

by liulongfang

[permalink] [raw]
Subject: [PATCH v4 0/5] add debugfs to migration driver

Add a debugfs function to the migration driver in VFIO to provide
a step-by-step test function for the migration driver.

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 v3 -> v4
Change the migration_debug_operate interface to debug_root file.

Changes v2 -> v3
Extend the debugfs function from hisilicon device to vfio.

Changes v1 -> v2
Change the registration method of root_debugfs to register
with module initialization.

Longfang Liu (5):
vfio/migration: Add debugfs to live migration driver
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_acc_vfio_pci
vfio: update live migration device status

.../ABI/testing/debugfs-hisi-migration | 32 ++
drivers/vfio/pci/Makefile | 4 +
.../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 274 +++++++++++++++++-
.../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 9 +
drivers/vfio/pci/mlx5/main.c | 3 +
drivers/vfio/pci/vfio_pci_core.c | 3 +
drivers/vfio/pci/vfio_pci_debugfs.c | 150 ++++++++++
drivers/vfio/pci/vfio_pci_debugfs.h | 32 ++
include/linux/vfio.h | 12 +
9 files changed, 509 insertions(+), 10 deletions(-)
create mode 100644 Documentation/ABI/testing/debugfs-hisi-migration
create mode 100644 drivers/vfio/pci/vfio_pci_debugfs.c
create mode 100644 drivers/vfio/pci/vfio_pci_debugfs.h

--
2.24.0


2022-12-02 10:03:06

by liulongfang

[permalink] [raw]
Subject: [PATCH v4 4/5] Documentation: add debugfs description for hisi_acc_vfio_pci

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

Signed-off-by: Longfang Liu <[email protected]>
---
.../ABI/testing/debugfs-hisi-migration | 32 +++++++++++++++++++
1 file changed, 32 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..a8cfc7688b88
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-hisi-migration
@@ -0,0 +1,32 @@
+What: /sys/kernel/debug/vfio_mig/<bdf>/state
+Date: Nov 2022
+Contact: [email protected]
+Description: Read the live migration status of the VF device.
+ The status of these live migrations includes:
+ ERROR, RUNNING, STOP, STOP_COPY, RESUMING.
+
+What: /sys/kernel/debug/vfio_mig/<bdf>/mig_data
+Date: Nov 2022
+Contact: [email protected]
+Description: Read the live migration data of the VF device.
+ The output format of the data is defined by the live
+ migration driver.
+
+What: /sys/kernel/debug/vfio_mig/<bdf>/mig_attr
+Date: Nov 2022
+Contact: [email protected]
+Description: Read the live migration attributes of the VF device.
+ The output format of the attributes is defined by the live
+ migration driver.
+
+What: /sys/kernel/debug/vfio_mig/<bdf>/debug
+Date: Nov 2022
+Contact: [email protected]
+Description: This debug file supports "echo" command write operations.
+ The command is actually represented by an integer number, and the
+ specific meaning is defined by the corresponding device driver.
+ For example, three commands are defined in the HiSilicon accelerator
+ live migration driver:
+ 0: State save
+ 1: State resume
+ 2: IO test
--
2.24.0

2022-12-02 10:04:02

by liulongfang

[permalink] [raw]
Subject: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver

There are multiple devices, software and operational steps involved
in the process of live migration. An error occurred on any node may
cause the live migration operation to fail.
This complex process makes it very difficult to locate and analyze
the cause when the function fails.

In order to quickly locate the cause of the problem when the
live migration fails, I added a set of debugfs to the vfio
live migration driver.

+------------------------------------------+
| |
| |
| QEMU |
| |
| |
+-----+-------------------------+----------+
| ^ | ^
v | v |
+-----+--+ +-----+--+
| src VF | | dst VF |
+-+------+ +-+------+
| ^ | ^
v | v |
+-------+-+------+ +-------+-+------+
| |state | | |state |
| +--------+ | +--------+
|Debugfs|mig_data| |Debugfs|mig_data|
| +--------+ | +--------+
| |mig_attr| | |mig_attr|
+-------+--------+ +-------+--------+
| debug_root | | debug_root |
+-------+--------+ +-------+--------+

debugfs will create a public root directory "vfio_mig" file.
then create a "debug_root" file and three debug files for each
live migration VF device.
state file: used to get the status of the live migration device.
mig_data file: used to get the migration data of the live migration device
mig_attr file: used to get device attributes of the live migration device
debug_root: used to create your own custom debug files for live
migration device drivers.

The live migration function of the current device can be tested by
operating the debug files, and the functional status of the equipment
and software at each stage can be tested step by step without
performing the complete live migration function. And after the live
migration is performed, the migration device data of the live migration
can be obtained through the debug files.

Signed-off-by: Longfang Liu <[email protected]>
---
drivers/vfio/pci/Makefile | 4 +
drivers/vfio/pci/vfio_pci_core.c | 3 +
drivers/vfio/pci/vfio_pci_debugfs.c | 142 ++++++++++++++++++++++++++++
drivers/vfio/pci/vfio_pci_debugfs.h | 32 +++++++
include/linux/vfio.h | 12 +++
5 files changed, 193 insertions(+)
create mode 100644 drivers/vfio/pci/vfio_pci_debugfs.c
create mode 100644 drivers/vfio/pci/vfio_pci_debugfs.h

diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
index 24c524224da5..efe032623664 100644
--- a/drivers/vfio/pci/Makefile
+++ b/drivers/vfio/pci/Makefile
@@ -4,6 +4,10 @@ vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_con
vfio-pci-core-$(CONFIG_VFIO_PCI_ZDEV_KVM) += vfio_pci_zdev.o
obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o

+ifneq ($(CONFIG_DEBUG_FS),)
+ vfio-pci-core-y += vfio_pci_debugfs.o
+endif
+
vfio-pci-y := vfio_pci.o
vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 189d4930c276..1d6dd61aef7d 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -28,6 +28,7 @@
#include <linux/nospec.h>
#include <linux/sched/mm.h>

+#include "vfio_pci_debugfs.h"
#include "vfio_pci_priv.h"

#define DRIVER_AUTHOR "Alex Williamson <[email protected]>"
@@ -2548,11 +2549,13 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_set_params);

static void vfio_pci_core_cleanup(void)
{
+ vfio_pci_debugfs_remove_root();
vfio_pci_uninit_perm_bits();
}

static int __init vfio_pci_core_init(void)
{
+ vfio_pci_debugfs_create_root();
/* Allocate shared config space permission data used by all devices */
return vfio_pci_init_perm_bits();
}
diff --git a/drivers/vfio/pci/vfio_pci_debugfs.c b/drivers/vfio/pci/vfio_pci_debugfs.c
new file mode 100644
index 000000000000..94a42869539e
--- /dev/null
+++ b/drivers/vfio/pci/vfio_pci_debugfs.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022, HiSilicon Ltd.
+ */
+
+#include <linux/pci.h>
+#include <linux/vfio_pci_core.h>
+
+#include "vfio_pci_debugfs.h"
+
+#define VFIO_DEV_BUF_LEN 4096
+static struct dentry *vfio_pci_debugfs_root;
+
+static ssize_t vfio_pci_vf_data_dump(struct file *filp, char __user *buffer,
+ size_t count, loff_t *pos)
+{
+ struct vfio_device *vdev = filp->private_data;
+ char tbuf[VFIO_DEV_BUF_LEN];
+ int len;
+
+ if (!vdev->mig_ops || !vdev->mig_ops->migration_get_data) {
+ dev_err(vdev->dev, "device not support get data!\n");
+ return -EINVAL;
+ }
+
+ len = vdev->mig_ops->migration_get_data(vdev, tbuf);
+
+ return simple_read_from_buffer(buffer, count, pos, tbuf, len);
+}
+
+static const struct file_operations vfio_vf_data_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = vfio_pci_vf_data_dump,
+};
+
+static ssize_t vfio_pci_vf_attr_show(struct file *filp, char __user *buffer,
+ size_t count, loff_t *pos)
+{
+ struct vfio_device *vdev = filp->private_data;
+ char tbuf[VFIO_DEV_BUF_LEN];
+ int len;
+
+ if (!vdev->mig_ops || !vdev->mig_ops->migration_get_attr) {
+ dev_err(vdev->dev, "device not support get attribute!\n");
+ return -EINVAL;
+ }
+
+ len = vdev->mig_ops->migration_get_attr(vdev, tbuf);
+
+ return simple_read_from_buffer(buffer, count, pos, tbuf, len);
+}
+
+static const struct file_operations vfio_vf_attr_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = vfio_pci_vf_attr_show,
+};
+
+static ssize_t vfio_pci_vf_state_read(struct file *filp, char __user *buffer,
+ size_t count, loff_t *pos)
+{
+ struct vfio_device *vdev = filp->private_data;
+ char buf[VFIO_DEV_DBG_LEN];
+ enum vfio_device_mig_state state;
+ int len;
+
+ (void)vdev->mig_ops->migration_get_state(vdev, &state);
+ switch (state) {
+ case VFIO_DEVICE_STATE_RUNNING:
+ len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
+ "RUNNING\n");
+ break;
+ case VFIO_DEVICE_STATE_STOP_COPY:
+ len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
+ "STOP_COPY\n");
+ break;
+ case VFIO_DEVICE_STATE_STOP:
+ len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
+ "STOP\n");
+ break;
+ case VFIO_DEVICE_STATE_RESUMING:
+ len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
+ "RESUMING\n");
+ break;
+ case VFIO_DEVICE_STATE_RUNNING_P2P:
+ len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
+ "RESUMING_P2P\n");
+ break;
+ case VFIO_DEVICE_STATE_ERROR:
+ len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
+ "ERROR\n");
+ break;
+ default:
+ len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
+ "Invalid\n");
+ }
+
+ return simple_read_from_buffer(buffer, count, pos, buf, len);
+}
+
+static const struct file_operations vfio_vf_state_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = vfio_pci_vf_state_read,
+};
+
+void vfio_pci_vf_debugfs_init(struct vfio_device *vdev)
+{
+ struct device *dev = vdev->dev;
+
+ vdev->debug_root = debugfs_create_dir(dev_name(dev), vfio_pci_debugfs_root);
+ debugfs_create_file("state", 0444, vdev->debug_root,
+ vdev, &vfio_vf_state_fops);
+
+ debugfs_create_file("mig_data", 0444, vdev->debug_root,
+ vdev, &vfio_vf_data_fops);
+
+ debugfs_create_file("mig_attr", 0444, vdev->debug_root,
+ vdev, &vfio_vf_attr_fops);
+}
+EXPORT_SYMBOL_GPL(vfio_pci_vf_debugfs_init);
+
+void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev)
+{
+ debugfs_remove_recursive(vdev->debug_root);
+}
+EXPORT_SYMBOL_GPL(vfio_pci_vf_debugfs_exit);
+
+void vfio_pci_debugfs_create_root(void)
+{
+ vfio_pci_debugfs_root = debugfs_create_dir("vfio_mig", NULL);
+}
+EXPORT_SYMBOL_GPL(vfio_pci_debugfs_create_root);
+
+void vfio_pci_debugfs_remove_root(void)
+{
+ debugfs_remove_recursive(vfio_pci_debugfs_root);
+ vfio_pci_debugfs_root = NULL;
+}
+EXPORT_SYMBOL_GPL(vfio_pci_debugfs_remove_root);
+
diff --git a/drivers/vfio/pci/vfio_pci_debugfs.h b/drivers/vfio/pci/vfio_pci_debugfs.h
new file mode 100644
index 000000000000..92031196a637
--- /dev/null
+++ b/drivers/vfio/pci/vfio_pci_debugfs.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * vfio_pci_debugfs.h - VFIO migration debugfs interface
+ *
+ * Copyright (c) 2022, HiSilicon Ltd.
+ *
+ * Author: Longfang Liu <[email protected]>
+ */
+
+#ifndef __VFIO_PCI_DEBUGFS_H
+#define __VFIO_PCI_DEBUGFS_H
+
+#include <linux/debugfs.h>
+#include <linux/vfio.h>
+
+#define VFIO_DEV_DBG_LEN 256
+
+#ifdef CONFIG_DEBUG_FS
+void vfio_pci_debugfs_create_root(void);
+void vfio_pci_debugfs_remove_root(void);
+
+void vfio_pci_vf_debugfs_init(struct vfio_device *vdev);
+void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev);
+#else
+static inline void vfio_pci_debugfs_create_root(void) { }
+static inline void vfio_pci_debugfs_remove_root(void) { }
+
+static inline void vfio_pci_vf_debugfs_init(struct vfio_device *vdev) { }
+static inline void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev) { }
+#endif /* CONFIG_DEBUG_FS */
+
+#endif /* __VFIO_PCI_DEBUGFS_H */
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 43b67e46a2cb..ee441ccdcc71 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -54,6 +54,12 @@ struct vfio_device {
struct completion comp;
struct list_head group_next;
struct list_head iommu_entry;
+
+ /*
+ * debug_root is a static property of the vfio_device
+ * which must be set prior to registering the vfio_device.
+ */
+ struct dentry *debug_root;
};

/**
@@ -110,6 +116,10 @@ struct vfio_device_ops {
* @migration_get_data_size: Optional callback to get the estimated data
* length that will be required to complete stop copy. It's mandatory for
* VFIO_DEVICE_FEATURE_MIGRATION migration support.
+ * @migration_get_data: Optional callback to get the migration data
+ * that will be required by vfio debugfs.
+ * @migration_get_attr: Optional callback to get the device attributes
+ * that will be required by vfio debugfs.
*/
struct vfio_migration_ops {
struct file *(*migration_set_state)(
@@ -119,6 +129,8 @@ struct vfio_migration_ops {
enum vfio_device_mig_state *curr_state);
int (*migration_get_data_size)(struct vfio_device *device,
unsigned long *stop_copy_length);
+ int (*migration_get_data)(struct vfio_device *device, char *buffer);
+ int (*migration_get_attr)(struct vfio_device *device, char *buffer);
};

/**
--
2.24.0

2022-12-02 10:07:10

by liulongfang

[permalink] [raw]
Subject: [PATCH v4 5/5] vfio: update live migration device status

migration debugfs needs to perform debug operations based on the
status of the current device. If the device is not loaded or has
stopped, debugfs does not allow operations.

so, after the live migration function is executed and the device is
turned off, the device no longer needs to be accessed. At this time,
the status of the device needs to be set to stop.

Signed-off-by: Longfang Liu <[email protected]>
---
drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 3 +++
drivers/vfio/pci/mlx5/main.c | 3 +++
2 files changed, 6 insertions(+)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index 0f35cde6e8ec..701fd2ca68b6 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -1458,6 +1458,9 @@ 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;

+ if (core_vdev->mig_ops)
+ hisi_acc_vdev->mig_state = VFIO_DEVICE_STATE_STOP;
+
iounmap(vf_qm->io_base);
vfio_pci_core_close_device(core_vdev);
}
diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
index 6e9cf2aacc52..0be038a8bf39 100644
--- a/drivers/vfio/pci/mlx5/main.c
+++ b/drivers/vfio/pci/mlx5/main.c
@@ -587,6 +587,9 @@ static void mlx5vf_pci_close_device(struct vfio_device *core_vdev)
struct mlx5vf_pci_core_device *mvdev = container_of(
core_vdev, struct mlx5vf_pci_core_device, core_device.vdev);

+ if (mvdev->migrate_cap)
+ mvdev->mig_state = VFIO_DEVICE_STATE_STOP;
+
mlx5vf_cmd_close_migratable(mvdev);
vfio_pci_core_close_device(core_vdev);
}
--
2.24.0

2022-12-02 10:08:54

by liulongfang

[permalink] [raw]
Subject: [PATCH v4 2/5] hisi_acc_vfio_pci: extract public functions for container_of

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, I extracted a public function
to replace it.

Signed-off-by: Longfang Liu <[email protected]>
---
.../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 0c0c0c7f0521..eb18edffbd5f 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -633,6 +633,12 @@ 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.
@@ -927,8 +933,7 @@ 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;
@@ -969,8 +974,7 @@ 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;
@@ -1186,8 +1190,7 @@ 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;

@@ -1210,8 +1213,7 @@ 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);
@@ -1226,8 +1228,7 @@ 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

2022-12-02 10:12:10

by liulongfang

[permalink] [raw]
Subject: [PATCH v4 3/5] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

On the debugfs framework of VFIO, register the debug function
for the live migration driver of the hisilicon accelerator device.

On the basis of the original public debug function, a private debug
function is added, so that the single-step debugging function
during live migration can be realized.

Signed-off-by: Longfang Liu <[email protected]>
---
.../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 250 ++++++++++++++++++
.../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 9 +
drivers/vfio/pci/vfio_pci_debugfs.c | 10 +-
3 files changed, 268 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index eb18edffbd5f..0f35cde6e8ec 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_pci_debugfs.h"

/* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
static int qm_wait_dev_not_ready(struct hisi_qm *qm)
@@ -609,6 +610,18 @@ 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 *src_migf,
+ struct hisi_acc_vf_migration_file *dst_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);
@@ -621,12 +634,16 @@ 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->resuming_migf,
+ hisi_acc_vdev->debug_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->saving_migf,
+ hisi_acc_vdev->debug_migf);
hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf);
fput(hisi_acc_vdev->saving_migf->filp);
hisi_acc_vdev->saving_migf = NULL;
@@ -1188,6 +1205,231 @@ 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_io(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;
+ struct device *dev = vdev->dev;
+ u64 data;
+ int ret;
+
+ data = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
+ dev_info(dev, "debug mailbox val: 0x%llx\n", data);
+
+ ret = qm_wait_dev_not_ready(vf_qm);
+ if (ret)
+ dev_err(dev, "VF device not ready!\n");
+
+ return ret;
+}
+
+static int hisi_acc_vf_debug_resume(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;
+ struct device *dev = vdev->dev;
+ int ret;
+
+ ret = vf_qm_state_save(hisi_acc_vdev, migf);
+ if (ret) {
+ dev_err(dev, "failed to save device data!\n");
+ return -EINVAL;
+ }
+
+ ret = vf_qm_check_match(hisi_acc_vdev, migf);
+ if (ret) {
+ dev_err(dev, "failed to match the VF!\n");
+ return -EINVAL;
+ }
+
+ ret = vf_qm_load_data(hisi_acc_vdev, migf);
+ if (ret) {
+ dev_err(dev, "failed to recover the VF!\n");
+ return -EINVAL;
+ }
+
+ vf_qm_fun_reset(&hisi_acc_vdev->vf_qm);
+ dev_info(dev, "successful to resume device data!\n");
+
+ return 0;
+}
+
+static int hisi_acc_vf_debug_save(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;
+ struct device *dev = vdev->dev;
+ int ret;
+
+ ret = vf_qm_state_save(hisi_acc_vdev, migf);
+ if (ret) {
+ dev_err(dev, "failed to save device data!\n");
+ return -EINVAL;
+ }
+ dev_info(dev, "successful to save device data!\n");
+
+ return 0;
+}
+
+static int
+hisi_acc_vf_debug_operate(struct vfio_device *vdev, unsigned int cmd)
+{
+ int ret;
+
+ switch (cmd) {
+ case STATE_SAVE:
+ ret = hisi_acc_vf_debug_save(vdev);
+ if (ret)
+ return ret;
+ break;
+ case STATE_RESUME:
+ ret = hisi_acc_vf_debug_resume(vdev);
+ if (ret)
+ return ret;
+ break;
+ case RW_IO_TEST:
+ ret = hisi_acc_vf_debug_io(vdev);
+ if (ret)
+ return ret;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int hisi_acc_vf_debug_check(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;
+ enum vfio_device_mig_state state;
+
+ if (!vdev->mig_ops || !migf) {
+ dev_err(vdev->dev, "device not support debugfs!\n");
+ return -EINVAL;
+ }
+
+ /* If device not opened, the debugfs operation will trigger calltrace */
+ (void)vdev->mig_ops->migration_get_state(vdev, &state);
+ if (state == VFIO_DEVICE_STATE_ERROR ||
+ state == VFIO_DEVICE_STATE_STOP) {
+ dev_err(vdev->dev, "device not opened!\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static ssize_t hisi_acc_vf_debug_write(struct file *filp, const char __user *buffer,
+ size_t count, loff_t *pos)
+{
+ struct vfio_device *vdev = filp->private_data;
+ char tbuf[VFIO_DEV_DBG_LEN];
+ unsigned long cmd;
+ int len, ret;
+
+ if (*pos)
+ return 0;
+
+ if (count >= VFIO_DEV_DBG_LEN)
+ return -ENOSPC;
+
+ ret = hisi_acc_vf_debug_check(vdev);
+ if (ret)
+ return -EINVAL;
+
+ len = simple_write_to_buffer(tbuf, VFIO_DEV_DBG_LEN - 1,
+ pos, buffer, count);
+ if (len < 0 || len > VFIO_DEV_DBG_LEN - 1)
+ return -EINVAL;
+ tbuf[len] = '\0';
+ if (kstrtoul(tbuf, 0, &cmd))
+ return -EFAULT;
+
+ ret = hisi_acc_vf_debug_operate(vdev, cmd);
+ if (ret) {
+ dev_err(vdev->dev, "device debug test failed!\n");
+ return -EINVAL;
+ }
+
+ return count;
+}
+
+static const struct file_operations hisi_acc_vf_debug_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .write = hisi_acc_vf_debug_write,
+};
+
+static int
+hisi_acc_vfio_pci_get_device_data(struct vfio_device *vdev, char *buff)
+{
+ 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);
+ struct device *dev = vdev->dev;
+
+ if (debug_migf && debug_migf->total_length) {
+ memcpy(buff, &debug_migf->vf_data, vf_data_sz);
+ return vf_data_sz;
+ }
+ dev_info(dev, "device not migrated!\n");
+
+ return 0;
+}
+
+static int
+hisi_acc_vfio_pci_get_device_attr(struct vfio_device *vdev, char *buff)
+{
+ 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;
+ struct device *dev = vdev->dev;
+
+ if (debug_migf && debug_migf->total_length) {
+ return scnprintf(buff, VFIO_DEV_DBG_LEN,
+ "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);
+ }
+ dev_info(dev, "device not migrated!\n");
+
+ 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;
+ void *migf = NULL;
+
+ vfio_pci_vf_debugfs_init(vdev);
+
+ migf = kzalloc(sizeof(struct hisi_acc_vf_migration_file), GFP_KERNEL);
+ if (!migf)
+ return -ENOMEM;
+
+ hisi_acc_vdev->debug_migf = migf;
+
+ debugfs_create_file("debug", 0200, vdev->debug_root,
+ vdev, &hisi_acc_vf_debug_fops);
+
+ return 0;
+}
+
+static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device *hisi_acc_vdev)
+{
+ struct vfio_device *vdev = &hisi_acc_vdev->core_device.vdev;
+
+ kfree(hisi_acc_vdev->debug_migf);
+ vfio_pci_vf_debugfs_exit(vdev);
+}
+
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);
@@ -1224,6 +1466,8 @@ static const struct vfio_migration_ops hisi_acc_vfio_pci_migrn_state_ops = {
.migration_set_state = hisi_acc_vfio_pci_set_device_state,
.migration_get_state = hisi_acc_vfio_pci_get_device_state,
.migration_get_data_size = hisi_acc_vfio_pci_get_data_size,
+ .migration_get_data = hisi_acc_vfio_pci_get_device_data,
+ .migration_get_attr = hisi_acc_vfio_pci_get_device_attr,
};

static int hisi_acc_vfio_pci_migrn_init_dev(struct vfio_device *core_vdev)
@@ -1295,6 +1539,9 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device
if (IS_ERR(hisi_acc_vdev))
return PTR_ERR(hisi_acc_vdev);

+ if (ops == &hisi_acc_vfio_pci_migrn_ops)
+ hisi_acc_vfio_debug_init(hisi_acc_vdev);
+
dev_set_drvdata(&pdev->dev, &hisi_acc_vdev->core_device);
ret = vfio_pci_core_register_device(&hisi_acc_vdev->core_device);
if (ret)
@@ -1302,6 +1549,8 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device
return 0;

out_put_vdev:
+ if (ops == &hisi_acc_vfio_pci_migrn_ops)
+ hisi_acc_vf_debugfs_exit(hisi_acc_vdev);
vfio_put_device(&hisi_acc_vdev->core_device.vdev);
return ret;
}
@@ -1310,6 +1559,7 @@ static void hisi_acc_vfio_pci_remove(struct pci_dev *pdev)
{
struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);

+ hisi_acc_vf_debugfs_exit(hisi_acc_vdev);
vfio_pci_core_unregister_device(&hisi_acc_vdev->core_device);
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 67343325b320..e9d72dc0c66c 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
@@ -49,6 +49,12 @@
#define QM_EQC_DW0 0X8000
#define QM_AEQC_DW0 0X8020

+enum mig_debug_cmd {
+ STATE_SAVE,
+ STATE_RESUME,
+ RW_IO_TEST,
+};
+
struct acc_vf_data {
#define QM_MATCH_SIZE offsetofend(struct acc_vf_data, qm_rsv_state)
/* QM match information */
@@ -111,5 +117,8 @@ 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;
+
+ /* For debugfs */
+ struct hisi_acc_vf_migration_file *debug_migf;
};
#endif /* HISI_ACC_VFIO_PCI_H */
diff --git a/drivers/vfio/pci/vfio_pci_debugfs.c b/drivers/vfio/pci/vfio_pci_debugfs.c
index 94a42869539e..a0cec2d17e16 100644
--- a/drivers/vfio/pci/vfio_pci_debugfs.c
+++ b/drivers/vfio/pci/vfio_pci_debugfs.c
@@ -8,7 +8,7 @@

#include "vfio_pci_debugfs.h"

-#define VFIO_DEV_BUF_LEN 4096
+#define VFIO_DEV_BUF_LEN 1024
static struct dentry *vfio_pci_debugfs_root;

static ssize_t vfio_pci_vf_data_dump(struct file *filp, char __user *buffer,
@@ -24,6 +24,10 @@ static ssize_t vfio_pci_vf_data_dump(struct file *filp, char __user *buffer,
}

len = vdev->mig_ops->migration_get_data(vdev, tbuf);
+ if (len < 0 || len >= VFIO_DEV_BUF_LEN) {
+ dev_err(vdev->dev, "failed to get device data!\n");
+ return -EINVAL;
+ }

return simple_read_from_buffer(buffer, count, pos, tbuf, len);
}
@@ -47,6 +51,10 @@ static ssize_t vfio_pci_vf_attr_show(struct file *filp, char __user *buffer,
}

len = vdev->mig_ops->migration_get_attr(vdev, tbuf);
+ if (len < 0 || len >= VFIO_DEV_BUF_LEN) {
+ dev_err(vdev->dev, "failed to get device attribute!\n");
+ return -EINVAL;
+ }

return simple_read_from_buffer(buffer, count, pos, tbuf, len);
}
--
2.24.0

Subject: RE: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver



> -----Original Message-----
> From: liulongfang
> Sent: 02 December 2022 09:26
> To: [email protected]; [email protected]; Shameerali Kolothum
> Thodi <[email protected]>; [email protected]
> Cc: [email protected]; [email protected];
> [email protected]; liulongfang <[email protected]>
> Subject: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver
>
> There are multiple devices, software and operational steps involved
> in the process of live migration. An error occurred on any node may
> cause the live migration operation to fail.
> This complex process makes it very difficult to locate and analyze
> the cause when the function fails.
>
> In order to quickly locate the cause of the problem when the
> live migration fails, I added a set of debugfs to the vfio
> live migration driver.
>
> +------------------------------------------+
> | |
> | |
> | QEMU |
> | |
> | |
> +-----+-------------------------+----------+
> | ^ | ^
> v | v |
> +-----+--+ +-----+--+
> | src VF | | dst VF |
> +-+------+ +-+------+
> | ^ | ^
> v | v |
> +-------+-+------+ +-------+-+------+
> | |state | | |state |
> | +--------+ | +--------+
> |Debugfs|mig_data| |Debugfs|mig_data|
> | +--------+ | +--------+
> | |mig_attr| | |mig_attr|
> +-------+--------+ +-------+--------+
> | debug_root | | debug_root |
> +-------+--------+ +-------+--------+
>
> debugfs will create a public root directory "vfio_mig" file.
> then create a "debug_root" file and three debug files for each
> live migration VF device.
> state file: used to get the status of the live migration device.
> mig_data file: used to get the migration data of the live migration device
> mig_attr file: used to get device attributes of the live migration device
> debug_root: used to create your own custom debug files for live
> migration device drivers.
>
> The live migration function of the current device can be tested by
> operating the debug files, and the functional status of the equipment
> and software at each stage can be tested step by step without
> performing the complete live migration function. And after the live
> migration is performed, the migration device data of the live migration
> can be obtained through the debug files.
>
> Signed-off-by: Longfang Liu <[email protected]>
> ---
> drivers/vfio/pci/Makefile | 4 +
> drivers/vfio/pci/vfio_pci_core.c | 3 +
> drivers/vfio/pci/vfio_pci_debugfs.c | 142 ++++++++++++++++++++++++++++
> drivers/vfio/pci/vfio_pci_debugfs.h | 32 +++++++
> include/linux/vfio.h | 12 +++
> 5 files changed, 193 insertions(+)
> create mode 100644 drivers/vfio/pci/vfio_pci_debugfs.c
> create mode 100644 drivers/vfio/pci/vfio_pci_debugfs.h
>
> diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
> index 24c524224da5..efe032623664 100644
> --- a/drivers/vfio/pci/Makefile
> +++ b/drivers/vfio/pci/Makefile
> @@ -4,6 +4,10 @@ vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o
> vfio_pci_rdwr.o vfio_pci_con
> vfio-pci-core-$(CONFIG_VFIO_PCI_ZDEV_KVM) += vfio_pci_zdev.o
> obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o
>
> +ifneq ($(CONFIG_DEBUG_FS),)
> + vfio-pci-core-y += vfio_pci_debugfs.o
> +endif
> +
> vfio-pci-y := vfio_pci.o
> vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
> obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index 189d4930c276..1d6dd61aef7d 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -28,6 +28,7 @@
> #include <linux/nospec.h>
> #include <linux/sched/mm.h>
>
> +#include "vfio_pci_debugfs.h"
> #include "vfio_pci_priv.h"
>
> #define DRIVER_AUTHOR "Alex Williamson
> <[email protected]>"
> @@ -2548,11 +2549,13 @@
> EXPORT_SYMBOL_GPL(vfio_pci_core_set_params);
>
> static void vfio_pci_core_cleanup(void)
> {
> + vfio_pci_debugfs_remove_root();
> vfio_pci_uninit_perm_bits();
> }
>
> static int __init vfio_pci_core_init(void)
> {
> + vfio_pci_debugfs_create_root();
> /* Allocate shared config space permission data used by all devices */
> return vfio_pci_init_perm_bits();
> }
> diff --git a/drivers/vfio/pci/vfio_pci_debugfs.c
> b/drivers/vfio/pci/vfio_pci_debugfs.c
> new file mode 100644
> index 000000000000..94a42869539e
> --- /dev/null
> +++ b/drivers/vfio/pci/vfio_pci_debugfs.c
> @@ -0,0 +1,142 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022, HiSilicon Ltd.
> + */
> +
> +#include <linux/pci.h>
> +#include <linux/vfio_pci_core.h>
> +
> +#include "vfio_pci_debugfs.h"
> +
> +#define VFIO_DEV_BUF_LEN 4096
> +static struct dentry *vfio_pci_debugfs_root;
> +
> +static ssize_t vfio_pci_vf_data_dump(struct file *filp, char __user *buffer,
> + size_t count, loff_t *pos)
> +{
> + struct vfio_device *vdev = filp->private_data;
> + char tbuf[VFIO_DEV_BUF_LEN];
> + int len;
> +
> + if (!vdev->mig_ops || !vdev->mig_ops->migration_get_data) {
> + dev_err(vdev->dev, "device not support get data!\n");
> + return -EINVAL;
> + }
> +
> + len = vdev->mig_ops->migration_get_data(vdev, tbuf);
> +
> + return simple_read_from_buffer(buffer, count, pos, tbuf, len);
> +}
> +
> +static const struct file_operations vfio_vf_data_fops = {
> + .owner = THIS_MODULE,
> + .open = simple_open,
> + .read = vfio_pci_vf_data_dump,
> +};
> +
> +static ssize_t vfio_pci_vf_attr_show(struct file *filp, char __user *buffer,
> + size_t count, loff_t *pos)
> +{
> + struct vfio_device *vdev = filp->private_data;
> + char tbuf[VFIO_DEV_BUF_LEN];
> + int len;
> +
> + if (!vdev->mig_ops || !vdev->mig_ops->migration_get_attr) {
> + dev_err(vdev->dev, "device not support get attribute!\n");
> + return -EINVAL;
> + }
> +
> + len = vdev->mig_ops->migration_get_attr(vdev, tbuf);
> +
> + return simple_read_from_buffer(buffer, count, pos, tbuf, len);
> +}
> +
> +static const struct file_operations vfio_vf_attr_fops = {
> + .owner = THIS_MODULE,
> + .open = simple_open,
> + .read = vfio_pci_vf_attr_show,
> +};
> +
> +static ssize_t vfio_pci_vf_state_read(struct file *filp, char __user *buffer,
> + size_t count, loff_t *pos)
> +{
> + struct vfio_device *vdev = filp->private_data;
> + char buf[VFIO_DEV_DBG_LEN];
> + enum vfio_device_mig_state state;
> + int len;
> +
> + (void)vdev->mig_ops->migration_get_state(vdev, &state);
> + switch (state) {
> + case VFIO_DEVICE_STATE_RUNNING:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "RUNNING\n");
> + break;
> + case VFIO_DEVICE_STATE_STOP_COPY:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "STOP_COPY\n");
> + break;
> + case VFIO_DEVICE_STATE_STOP:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "STOP\n");
> + break;
> + case VFIO_DEVICE_STATE_RESUMING:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "RESUMING\n");
> + break;
> + case VFIO_DEVICE_STATE_RUNNING_P2P:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "RESUMING_P2P\n");
> + break;
> + case VFIO_DEVICE_STATE_ERROR:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "ERROR\n");
> + break;
> + default:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "Invalid\n");
> + }
> +
> + return simple_read_from_buffer(buffer, count, pos, buf, len);
> +}
> +
> +static const struct file_operations vfio_vf_state_fops = {
> + .owner = THIS_MODULE,
> + .open = simple_open,
> + .read = vfio_pci_vf_state_read,
> +};
> +
> +void vfio_pci_vf_debugfs_init(struct vfio_device *vdev)
> +{
> + struct device *dev = vdev->dev;
> +
> + vdev->debug_root = debugfs_create_dir(dev_name(dev),
> vfio_pci_debugfs_root);
> + debugfs_create_file("state", 0444, vdev->debug_root,
> + vdev, &vfio_vf_state_fops);
> +
> + debugfs_create_file("mig_data", 0444, vdev->debug_root,
> + vdev, &vfio_vf_data_fops);
> +
> + debugfs_create_file("mig_attr", 0444, vdev->debug_root,
> + vdev, &vfio_vf_attr_fops);

I would probably avoid creating the mig_attr as well in the common code,
retaining only the "state" and optional "mig_data" here.


Thanks,
Shameer

> +}
> +EXPORT_SYMBOL_GPL(vfio_pci_vf_debugfs_init);
> +
> +void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev)
> +{
> + debugfs_remove_recursive(vdev->debug_root);
> +}
> +EXPORT_SYMBOL_GPL(vfio_pci_vf_debugfs_exit);
> +
> +void vfio_pci_debugfs_create_root(void)
> +{
> + vfio_pci_debugfs_root = debugfs_create_dir("vfio_mig", NULL);
> +}
> +EXPORT_SYMBOL_GPL(vfio_pci_debugfs_create_root);
> +
> +void vfio_pci_debugfs_remove_root(void)
> +{
> + debugfs_remove_recursive(vfio_pci_debugfs_root);
> + vfio_pci_debugfs_root = NULL;
> +}
> +EXPORT_SYMBOL_GPL(vfio_pci_debugfs_remove_root);
> +
> diff --git a/drivers/vfio/pci/vfio_pci_debugfs.h
> b/drivers/vfio/pci/vfio_pci_debugfs.h
> new file mode 100644
> index 000000000000..92031196a637
> --- /dev/null
> +++ b/drivers/vfio/pci/vfio_pci_debugfs.h
> @@ -0,0 +1,32 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * vfio_pci_debugfs.h - VFIO migration debugfs interface
> + *
> + * Copyright (c) 2022, HiSilicon Ltd.
> + *
> + * Author: Longfang Liu <[email protected]>
> + */
> +
> +#ifndef __VFIO_PCI_DEBUGFS_H
> +#define __VFIO_PCI_DEBUGFS_H
> +
> +#include <linux/debugfs.h>
> +#include <linux/vfio.h>
> +
> +#define VFIO_DEV_DBG_LEN 256
> +
> +#ifdef CONFIG_DEBUG_FS
> +void vfio_pci_debugfs_create_root(void);
> +void vfio_pci_debugfs_remove_root(void);
> +
> +void vfio_pci_vf_debugfs_init(struct vfio_device *vdev);
> +void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev);
> +#else
> +static inline void vfio_pci_debugfs_create_root(void) { }
> +static inline void vfio_pci_debugfs_remove_root(void) { }
> +
> +static inline void vfio_pci_vf_debugfs_init(struct vfio_device *vdev) { }
> +static inline void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev) { }
> +#endif /* CONFIG_DEBUG_FS */
> +
> +#endif /* __VFIO_PCI_DEBUGFS_H */
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 43b67e46a2cb..ee441ccdcc71 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -54,6 +54,12 @@ struct vfio_device {
> struct completion comp;
> struct list_head group_next;
> struct list_head iommu_entry;
> +
> + /*
> + * debug_root is a static property of the vfio_device
> + * which must be set prior to registering the vfio_device.
> + */
> + struct dentry *debug_root;
> };
>
> /**
> @@ -110,6 +116,10 @@ struct vfio_device_ops {
> * @migration_get_data_size: Optional callback to get the estimated data
> * length that will be required to complete stop copy. It's
> mandatory for
> * VFIO_DEVICE_FEATURE_MIGRATION migration support.
> + * @migration_get_data: Optional callback to get the migration data
> + * that will be required by vfio debugfs.
> + * @migration_get_attr: Optional callback to get the device attributes
> + * that will be required by vfio debugfs.
> */
> struct vfio_migration_ops {
> struct file *(*migration_set_state)(
> @@ -119,6 +129,8 @@ struct vfio_migration_ops {
> enum vfio_device_mig_state *curr_state);
> int (*migration_get_data_size)(struct vfio_device *device,
> unsigned long *stop_copy_length);
> + int (*migration_get_data)(struct vfio_device *device, char *buffer);
> + int (*migration_get_attr)(struct vfio_device *device, char *buffer);
> };
>
> /**
> --
> 2.24.0

2022-12-02 15:27:59

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH v4 3/5] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

On Fri, Dec 02, 2022 at 05:26:23PM +0800, Longfang Liu wrote:
> On the debugfs framework of VFIO, register the debug function
> for the live migration driver of the hisilicon accelerator device.
>
> On the basis of the original public debug function, a private debug
> function is added, so that the single-step debugging function
> during live migration can be realized.
>
> Signed-off-by: Longfang Liu <[email protected]>
> ---
> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 250 ++++++++++++++++++
> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 9 +
> drivers/vfio/pci/vfio_pci_debugfs.c | 10 +-
> 3 files changed, 268 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> index eb18edffbd5f..0f35cde6e8ec 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_pci_debugfs.h"
>
> /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
> static int qm_wait_dev_not_ready(struct hisi_qm *qm)
> @@ -609,6 +610,18 @@ 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 *src_migf,
> + struct hisi_acc_vf_migration_file *dst_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);
> @@ -621,12 +634,16 @@ 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->resuming_migf,
> + hisi_acc_vdev->debug_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->saving_migf,
> + hisi_acc_vdev->debug_migf);
> hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf);
> fput(hisi_acc_vdev->saving_migf->filp);
> hisi_acc_vdev->saving_migf = NULL;
> @@ -1188,6 +1205,231 @@ 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_io(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;
> + struct device *dev = vdev->dev;
> + u64 data;
> + int ret;
> +
> + data = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
> + dev_info(dev, "debug mailbox val: 0x%llx\n", data);
> +
> + ret = qm_wait_dev_not_ready(vf_qm);
> + if (ret)
> + dev_err(dev, "VF device not ready!\n");

debugfs has helpers for this, you should use debugfs_print_regs32()

> +static int hisi_acc_vf_debug_resume(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;
> + struct device *dev = vdev->dev;
> + int ret;
> +
> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
> + if (ret) {
> + dev_err(dev, "failed to save device data!\n");
> + return -EINVAL;
> + }
> +
> + ret = vf_qm_check_match(hisi_acc_vdev, migf);
> + if (ret) {
> + dev_err(dev, "failed to match the VF!\n");
> + return -EINVAL;
> + }
> +
> + ret = vf_qm_load_data(hisi_acc_vdev, migf);
> + if (ret) {
> + dev_err(dev, "failed to recover the VF!\n");
> + return -EINVAL;
> + }
> +
> + vf_qm_fun_reset(&hisi_acc_vdev->vf_qm);
> + dev_info(dev, "successful to resume device data!\n");
> +
> + return 0;
> +}

This doesn't seem like it belongs in debugfs at all, please just write
a test progam using normal vfio ioctls to do these steps and put in
the kernel selftests directory.

> +static int hisi_acc_vf_debug_save(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;
> + struct device *dev = vdev->dev;
> + int ret;
> +
> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
> + if (ret) {
> + dev_err(dev, "failed to save device data!\n");
> + return -EINVAL;
> + }
> + dev_info(dev, "successful to save device data!\n");
> +
> + return 0;
> +}

Ditto, I don't think debugfs should be accessing the device state
independently of the main FSM.

Jason

2022-12-02 16:08:20

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver

On Fri, Dec 02, 2022 at 05:26:21PM +0800, Longfang Liu wrote:

> +static ssize_t vfio_pci_vf_state_read(struct file *filp, char __user *buffer,
> + size_t count, loff_t *pos)
> +{

This would be better to use debugfs_create_devm_seqfile()

Then you can simply use seq_printf()

> @@ -119,6 +129,8 @@ struct vfio_migration_ops {
> enum vfio_device_mig_state *curr_state);
> int (*migration_get_data_size)(struct vfio_device *device,
> unsigned long *stop_copy_length);
> + int (*migration_get_data)(struct vfio_device *device, char *buffer);
> + int (*migration_get_attr)(struct vfio_device *device, char
> *buffer);

Still no to passing through debugfs ops, create these files in the
driver.

Jason

2022-12-05 14:13:55

by liulongfang

[permalink] [raw]
Subject: Re: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver

On 2022/12/2 18:02, Shameerali Kolothum Thodi wrote:
>
>
>> -----Original Message-----
>> From: liulongfang
>> Sent: 02 December 2022 09:26
>> To: [email protected]; [email protected]; Shameerali Kolothum
>> Thodi <[email protected]>; [email protected]
>> Cc: [email protected]; [email protected];
>> [email protected]; liulongfang <[email protected]>
>> Subject: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver
>>
>> There are multiple devices, software and operational steps involved
>> in the process of live migration. An error occurred on any node may
>> cause the live migration operation to fail.
>> This complex process makes it very difficult to locate and analyze
>> the cause when the function fails.
>>
>> In order to quickly locate the cause of the problem when the
>> live migration fails, I added a set of debugfs to the vfio
>> live migration driver.
>>
>> +------------------------------------------+
>> | |
>> | |
>> | QEMU |
>> | |
>> | |
>> +-----+-------------------------+----------+
>> | ^ | ^
>> v | v |
>> +-----+--+ +-----+--+
>> | src VF | | dst VF |
>> +-+------+ +-+------+
>> | ^ | ^
>> v | v |
>> +-------+-+------+ +-------+-+------+
>> | |state | | |state |
>> | +--------+ | +--------+
>> |Debugfs|mig_data| |Debugfs|mig_data|
>> | +--------+ | +--------+
>> | |mig_attr| | |mig_attr|
>> +-------+--------+ +-------+--------+
>> | debug_root | | debug_root |
>> +-------+--------+ +-------+--------+
>>
>> debugfs will create a public root directory "vfio_mig" file.
>> then create a "debug_root" file and three debug files for each
>> live migration VF device.
>> state file: used to get the status of the live migration device.
>> mig_data file: used to get the migration data of the live migration device
>> mig_attr file: used to get device attributes of the live migration device
>> debug_root: used to create your own custom debug files for live
>> migration device drivers.
>>
>> The live migration function of the current device can be tested by
>> operating the debug files, and the functional status of the equipment
>> and software at each stage can be tested step by step without
>> performing the complete live migration function. And after the live
>> migration is performed, the migration device data of the live migration
>> can be obtained through the debug files.
>>
>> Signed-off-by: Longfang Liu <[email protected]>
>> ---
>> drivers/vfio/pci/Makefile | 4 +
>> drivers/vfio/pci/vfio_pci_core.c | 3 +
>> drivers/vfio/pci/vfio_pci_debugfs.c | 142 ++++++++++++++++++++++++++++
>> drivers/vfio/pci/vfio_pci_debugfs.h | 32 +++++++
>> include/linux/vfio.h | 12 +++
>> 5 files changed, 193 insertions(+)
>> create mode 100644 drivers/vfio/pci/vfio_pci_debugfs.c
>> create mode 100644 drivers/vfio/pci/vfio_pci_debugfs.h
>>
>> diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
>> index 24c524224da5..efe032623664 100644
>> --- a/drivers/vfio/pci/Makefile
>> +++ b/drivers/vfio/pci/Makefile
>> @@ -4,6 +4,10 @@ vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o
>> vfio_pci_rdwr.o vfio_pci_con
>> vfio-pci-core-$(CONFIG_VFIO_PCI_ZDEV_KVM) += vfio_pci_zdev.o
>> obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o
>>
>> +ifneq ($(CONFIG_DEBUG_FS),)
>> + vfio-pci-core-y += vfio_pci_debugfs.o
>> +endif
>> +
>> vfio-pci-y := vfio_pci.o
>> vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
>> obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
>> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
>> index 189d4930c276..1d6dd61aef7d 100644
>> --- a/drivers/vfio/pci/vfio_pci_core.c
>> +++ b/drivers/vfio/pci/vfio_pci_core.c
>> @@ -28,6 +28,7 @@
>> #include <linux/nospec.h>
>> #include <linux/sched/mm.h>
>>
>> +#include "vfio_pci_debugfs.h"
>> #include "vfio_pci_priv.h"
>>
>> #define DRIVER_AUTHOR "Alex Williamson
>> <[email protected]>"
>> @@ -2548,11 +2549,13 @@
>> EXPORT_SYMBOL_GPL(vfio_pci_core_set_params);
>>
>> static void vfio_pci_core_cleanup(void)
>> {
>> + vfio_pci_debugfs_remove_root();
>> vfio_pci_uninit_perm_bits();
>> }
>>
>> static int __init vfio_pci_core_init(void)
>> {
>> + vfio_pci_debugfs_create_root();
>> /* Allocate shared config space permission data used by all devices */
>> return vfio_pci_init_perm_bits();
>> }
>> diff --git a/drivers/vfio/pci/vfio_pci_debugfs.c
>> b/drivers/vfio/pci/vfio_pci_debugfs.c
>> new file mode 100644
>> index 000000000000..94a42869539e
>> --- /dev/null
>> +++ b/drivers/vfio/pci/vfio_pci_debugfs.c
>> @@ -0,0 +1,142 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2022, HiSilicon Ltd.
>> + */
>> +
>> +#include <linux/pci.h>
>> +#include <linux/vfio_pci_core.h>
>> +
>> +#include "vfio_pci_debugfs.h"
>> +
>> +#define VFIO_DEV_BUF_LEN 4096
>> +static struct dentry *vfio_pci_debugfs_root;
>> +
>> +static ssize_t vfio_pci_vf_data_dump(struct file *filp, char __user *buffer,
>> + size_t count, loff_t *pos)
>> +{
>> + struct vfio_device *vdev = filp->private_data;
>> + char tbuf[VFIO_DEV_BUF_LEN];
>> + int len;
>> +
>> + if (!vdev->mig_ops || !vdev->mig_ops->migration_get_data) {
>> + dev_err(vdev->dev, "device not support get data!\n");
>> + return -EINVAL;
>> + }
>> +
>> + len = vdev->mig_ops->migration_get_data(vdev, tbuf);
>> +
>> + return simple_read_from_buffer(buffer, count, pos, tbuf, len);
>> +}
>> +
>> +static const struct file_operations vfio_vf_data_fops = {
>> + .owner = THIS_MODULE,
>> + .open = simple_open,
>> + .read = vfio_pci_vf_data_dump,
>> +};
>> +
>> +static ssize_t vfio_pci_vf_attr_show(struct file *filp, char __user *buffer,
>> + size_t count, loff_t *pos)
>> +{
>> + struct vfio_device *vdev = filp->private_data;
>> + char tbuf[VFIO_DEV_BUF_LEN];
>> + int len;
>> +
>> + if (!vdev->mig_ops || !vdev->mig_ops->migration_get_attr) {
>> + dev_err(vdev->dev, "device not support get attribute!\n");
>> + return -EINVAL;
>> + }
>> +
>> + len = vdev->mig_ops->migration_get_attr(vdev, tbuf);
>> +
>> + return simple_read_from_buffer(buffer, count, pos, tbuf, len);
>> +}
>> +
>> +static const struct file_operations vfio_vf_attr_fops = {
>> + .owner = THIS_MODULE,
>> + .open = simple_open,
>> + .read = vfio_pci_vf_attr_show,
>> +};
>> +
>> +static ssize_t vfio_pci_vf_state_read(struct file *filp, char __user *buffer,
>> + size_t count, loff_t *pos)
>> +{
>> + struct vfio_device *vdev = filp->private_data;
>> + char buf[VFIO_DEV_DBG_LEN];
>> + enum vfio_device_mig_state state;
>> + int len;
>> +
>> + (void)vdev->mig_ops->migration_get_state(vdev, &state);
>> + switch (state) {
>> + case VFIO_DEVICE_STATE_RUNNING:
>> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
>> + "RUNNING\n");
>> + break;
>> + case VFIO_DEVICE_STATE_STOP_COPY:
>> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
>> + "STOP_COPY\n");
>> + break;
>> + case VFIO_DEVICE_STATE_STOP:
>> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
>> + "STOP\n");
>> + break;
>> + case VFIO_DEVICE_STATE_RESUMING:
>> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
>> + "RESUMING\n");
>> + break;
>> + case VFIO_DEVICE_STATE_RUNNING_P2P:
>> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
>> + "RESUMING_P2P\n");
>> + break;
>> + case VFIO_DEVICE_STATE_ERROR:
>> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
>> + "ERROR\n");
>> + break;
>> + default:
>> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
>> + "Invalid\n");
>> + }
>> +
>> + return simple_read_from_buffer(buffer, count, pos, buf, len);
>> +}
>> +
>> +static const struct file_operations vfio_vf_state_fops = {
>> + .owner = THIS_MODULE,
>> + .open = simple_open,
>> + .read = vfio_pci_vf_state_read,
>> +};
>> +
>> +void vfio_pci_vf_debugfs_init(struct vfio_device *vdev)
>> +{
>> + struct device *dev = vdev->dev;
>> +
>> + vdev->debug_root = debugfs_create_dir(dev_name(dev),
>> vfio_pci_debugfs_root);
>> + debugfs_create_file("state", 0444, vdev->debug_root,
>> + vdev, &vfio_vf_state_fops);
>> +
>> + debugfs_create_file("mig_data", 0444, vdev->debug_root,
>> + vdev, &vfio_vf_data_fops);
>> +
>> + debugfs_create_file("mig_attr", 0444, vdev->debug_root,
>> + vdev, &vfio_vf_attr_fops);
>
> I would probably avoid creating the mig_attr as well in the common code,
> retaining only the "state" and optional "mig_data" here.
>


In the live migration driver, in addition to the device state and device migration data,
the functional attributes of the migrating device should also be a common part.

Thanks,
Longfang.

>
> Thanks,
> Shameer
>
>> +}
>> +EXPORT_SYMBOL_GPL(vfio_pci_vf_debugfs_init);
>> +
>> +void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev)
>> +{
>> + debugfs_remove_recursive(vdev->debug_root);
>> +}
>> +EXPORT_SYMBOL_GPL(vfio_pci_vf_debugfs_exit);
>> +
>> +void vfio_pci_debugfs_create_root(void)
>> +{
>> + vfio_pci_debugfs_root = debugfs_create_dir("vfio_mig", NULL);
>> +}
>> +EXPORT_SYMBOL_GPL(vfio_pci_debugfs_create_root);
>> +
>> +void vfio_pci_debugfs_remove_root(void)
>> +{
>> + debugfs_remove_recursive(vfio_pci_debugfs_root);
>> + vfio_pci_debugfs_root = NULL;
>> +}
>> +EXPORT_SYMBOL_GPL(vfio_pci_debugfs_remove_root);
>> +
>> diff --git a/drivers/vfio/pci/vfio_pci_debugfs.h
>> b/drivers/vfio/pci/vfio_pci_debugfs.h
>> new file mode 100644
>> index 000000000000..92031196a637
>> --- /dev/null
>> +++ b/drivers/vfio/pci/vfio_pci_debugfs.h
>> @@ -0,0 +1,32 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * vfio_pci_debugfs.h - VFIO migration debugfs interface
>> + *
>> + * Copyright (c) 2022, HiSilicon Ltd.
>> + *
>> + * Author: Longfang Liu <[email protected]>
>> + */
>> +
>> +#ifndef __VFIO_PCI_DEBUGFS_H
>> +#define __VFIO_PCI_DEBUGFS_H
>> +
>> +#include <linux/debugfs.h>
>> +#include <linux/vfio.h>
>> +
>> +#define VFIO_DEV_DBG_LEN 256
>> +
>> +#ifdef CONFIG_DEBUG_FS
>> +void vfio_pci_debugfs_create_root(void);
>> +void vfio_pci_debugfs_remove_root(void);
>> +
>> +void vfio_pci_vf_debugfs_init(struct vfio_device *vdev);
>> +void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev);
>> +#else
>> +static inline void vfio_pci_debugfs_create_root(void) { }
>> +static inline void vfio_pci_debugfs_remove_root(void) { }
>> +
>> +static inline void vfio_pci_vf_debugfs_init(struct vfio_device *vdev) { }
>> +static inline void vfio_pci_vf_debugfs_exit(struct vfio_device *vdev) { }
>> +#endif /* CONFIG_DEBUG_FS */
>> +
>> +#endif /* __VFIO_PCI_DEBUGFS_H */
>> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
>> index 43b67e46a2cb..ee441ccdcc71 100644
>> --- a/include/linux/vfio.h
>> +++ b/include/linux/vfio.h
>> @@ -54,6 +54,12 @@ struct vfio_device {
>> struct completion comp;
>> struct list_head group_next;
>> struct list_head iommu_entry;
>> +
>> + /*
>> + * debug_root is a static property of the vfio_device
>> + * which must be set prior to registering the vfio_device.
>> + */
>> + struct dentry *debug_root;
>> };
>>
>> /**
>> @@ -110,6 +116,10 @@ struct vfio_device_ops {
>> * @migration_get_data_size: Optional callback to get the estimated data
>> * length that will be required to complete stop copy. It's
>> mandatory for
>> * VFIO_DEVICE_FEATURE_MIGRATION migration support.
>> + * @migration_get_data: Optional callback to get the migration data
>> + * that will be required by vfio debugfs.
>> + * @migration_get_attr: Optional callback to get the device attributes
>> + * that will be required by vfio debugfs.
>> */
>> struct vfio_migration_ops {
>> struct file *(*migration_set_state)(
>> @@ -119,6 +129,8 @@ struct vfio_migration_ops {
>> enum vfio_device_mig_state *curr_state);
>> int (*migration_get_data_size)(struct vfio_device *device,
>> unsigned long *stop_copy_length);
>> + int (*migration_get_data)(struct vfio_device *device, char *buffer);
>> + int (*migration_get_attr)(struct vfio_device *device, char *buffer);
>> };
>>
>> /**
>> --
>> 2.24.0
>
> .
>

2022-12-05 14:22:48

by liulongfang

[permalink] [raw]
Subject: Re: [PATCH v4 3/5] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

On 2022/12/2 23:21, Jason Gunthorpe wrote:
> On Fri, Dec 02, 2022 at 05:26:23PM +0800, Longfang Liu wrote:
>> On the debugfs framework of VFIO, register the debug function
>> for the live migration driver of the hisilicon accelerator device.
>>
>> On the basis of the original public debug function, a private debug
>> function is added, so that the single-step debugging function
>> during live migration can be realized.
>>
>> Signed-off-by: Longfang Liu <[email protected]>
>> ---
>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 250 ++++++++++++++++++
>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 9 +
>> drivers/vfio/pci/vfio_pci_debugfs.c | 10 +-
>> 3 files changed, 268 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> index eb18edffbd5f..0f35cde6e8ec 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_pci_debugfs.h"
>>
>> /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
>> static int qm_wait_dev_not_ready(struct hisi_qm *qm)
>> @@ -609,6 +610,18 @@ 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 *src_migf,
>> + struct hisi_acc_vf_migration_file *dst_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);
>> @@ -621,12 +634,16 @@ 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->resuming_migf,
>> + hisi_acc_vdev->debug_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->saving_migf,
>> + hisi_acc_vdev->debug_migf);
>> hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf);
>> fput(hisi_acc_vdev->saving_migf->filp);
>> hisi_acc_vdev->saving_migf = NULL;
>> @@ -1188,6 +1205,231 @@ 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_io(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;
>> + struct device *dev = vdev->dev;
>> + u64 data;
>> + int ret;
>> +
>> + data = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
>> + dev_info(dev, "debug mailbox val: 0x%llx\n", data);
>> +
>> + ret = qm_wait_dev_not_ready(vf_qm);
>> + if (ret)
>> + dev_err(dev, "VF device not ready!\n");
>
> debugfs has helpers for this, you should use debugfs_print_regs32()
>

Yes, it is now possible to use this public interface in debugfs to
implement this read register function.

Thanks,
Longfang.

>> +static int hisi_acc_vf_debug_resume(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;
>> + struct device *dev = vdev->dev;
>> + int ret;
>> +
>> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to save device data!\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = vf_qm_check_match(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to match the VF!\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = vf_qm_load_data(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to recover the VF!\n");
>> + return -EINVAL;
>> + }
>> +
>> + vf_qm_fun_reset(&hisi_acc_vdev->vf_qm);
>> + dev_info(dev, "successful to resume device data!\n");
>> +
>> + return 0;
>> +}
>
> This doesn't seem like it belongs in debugfs at all, please just write
> a test progam using normal vfio ioctls to do these steps and put in
> the kernel selftests directory.
>
>> +static int hisi_acc_vf_debug_save(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;
>> + struct device *dev = vdev->dev;
>> + int ret;
>> +
>> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to save device data!\n");
>> + return -EINVAL;
>> + }
>> + dev_info(dev, "successful to save device data!\n");
>> +
>> + return 0;
>> +}
>
> Ditto, I don't think debugfs should be accessing the device state
> independently of the main FSM.
>
> Jason
> .
>

2022-12-05 14:22:49

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver

On Mon, Dec 05, 2022 at 09:39:29PM +0800, liulongfang wrote:
> On 2022/12/2 23:17, Jason Gunthorpe wrote:
> > On Fri, Dec 02, 2022 at 05:26:21PM +0800, Longfang Liu wrote:
> >
> >> +static ssize_t vfio_pci_vf_state_read(struct file *filp, char __user *buffer,
> >> + size_t count, loff_t *pos)
> >> +{
> >
> > This would be better to use debugfs_create_devm_seqfile()
> >
> > Then you can simply use seq_printf()
> >
>
> The previous debugfs used this method in my patch.
> Is it now recommended to use the interface with "devm" ?

It doesn't matter, the point is not the devm, it is to use the right
helper for the data you want to expose over debugfs

> >> @@ -119,6 +129,8 @@ struct vfio_migration_ops {
> >> enum vfio_device_mig_state *curr_state);
> >> int (*migration_get_data_size)(struct vfio_device *device,
> >> unsigned long *stop_copy_length);
> >> + int (*migration_get_data)(struct vfio_device *device, char *buffer);
> >> + int (*migration_get_attr)(struct vfio_device *device, char
> >> *buffer);
> >
> > Still no to passing through debugfs ops, create these files in the
> > driver.
> >
>
> If this part is also created and enabled in the device driver, why do we need
> to put this debugfs in the vfio public framework?

To create the directory, and the few actually common files

Jason

2022-12-05 14:47:06

by liulongfang

[permalink] [raw]
Subject: Re: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver

On 2022/12/2 23:17, Jason Gunthorpe wrote:
> On Fri, Dec 02, 2022 at 05:26:21PM +0800, Longfang Liu wrote:
>
>> +static ssize_t vfio_pci_vf_state_read(struct file *filp, char __user *buffer,
>> + size_t count, loff_t *pos)
>> +{
>
> This would be better to use debugfs_create_devm_seqfile()
>
> Then you can simply use seq_printf()
>

The previous debugfs used this method in my patch.
Is it now recommended to use the interface with "devm" ?


>> @@ -119,6 +129,8 @@ struct vfio_migration_ops {
>> enum vfio_device_mig_state *curr_state);
>> int (*migration_get_data_size)(struct vfio_device *device,
>> unsigned long *stop_copy_length);
>> + int (*migration_get_data)(struct vfio_device *device, char *buffer);
>> + int (*migration_get_attr)(struct vfio_device *device, char
>> *buffer);
>
> Still no to passing through debugfs ops, create these files in the
> driver.
>

If this part is also created and enabled in the device driver, why do we need
to put this debugfs in the vfio public framework?

Thanks,
Longfang.
> Jason
> .
>

2022-12-08 08:59:37

by liulongfang

[permalink] [raw]
Subject: Re: [PATCH v4 1/5] vfio/migration: Add debugfs to live migration driver

On 2022/12/5 21:55, Jason Gunthorpe Wrote:
> On Mon, Dec 05, 2022 at 09:39:29PM +0800, liulongfang wrote:
>> On 2022/12/2 23:17, Jason Gunthorpe wrote:
>>> On Fri, Dec 02, 2022 at 05:26:21PM +0800, Longfang Liu wrote:
>>>
>>>> +static ssize_t vfio_pci_vf_state_read(struct file *filp, char __user *buffer,
>>>> + size_t count, loff_t *pos)
>>>> +{
>>>
>>> This would be better to use debugfs_create_devm_seqfile()
>>>
>>> Then you can simply use seq_printf()
>>>
>>
>> The previous debugfs used this method in my patch.
>> Is it now recommended to use the interface with "devm" ?
>
> It doesn't matter, the point is not the devm, it is to use the right
> helper for the data you want to expose over debugfs
>
>>>> @@ -119,6 +129,8 @@ struct vfio_migration_ops {
>>>> enum vfio_device_mig_state *curr_state);
>>>> int (*migration_get_data_size)(struct vfio_device *device,
>>>> unsigned long *stop_copy_length);
>>>> + int (*migration_get_data)(struct vfio_device *device, char *buffer);
>>>> + int (*migration_get_attr)(struct vfio_device *device, char
>>>> *buffer);
>>>
>>> Still no to passing through debugfs ops, create these files in the
>>> driver.
>>>
>>
>> If this part is also created and enabled in the device driver, why do we need
>> to put this debugfs in the vfio public framework?
>
> To create the directory, and the few actually common files
>

OK, Only use the state as a public function, and create other debug files
inside the driver.

Thanks,
Longfang.
> Jason
> .
>

2022-12-09 09:13:12

by liulongfang

[permalink] [raw]
Subject: Re: [PATCH v4 3/5] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver



?? 2022/12/2 23:21, Jason Gunthorpe ะด??:
> On Fri, Dec 02, 2022 at 05:26:23PM +0800, Longfang Liu wrote:
>> On the debugfs framework of VFIO, register the debug function
>> for the live migration driver of the hisilicon accelerator device.
>>
>> On the basis of the original public debug function, a private debug
>> function is added, so that the single-step debugging function
>> during live migration can be realized.
>>
>> Signed-off-by: Longfang Liu <[email protected]>
>> ---
>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 250 ++++++++++++++++++
>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 9 +
>> drivers/vfio/pci/vfio_pci_debugfs.c | 10 +-
>> 3 files changed, 268 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> index eb18edffbd5f..0f35cde6e8ec 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_pci_debugfs.h"
>>
>> /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
>> static int qm_wait_dev_not_ready(struct hisi_qm *qm)
>> @@ -609,6 +610,18 @@ 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 *src_migf,
>> + struct hisi_acc_vf_migration_file *dst_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);
>> @@ -621,12 +634,16 @@ 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->resuming_migf,
>> + hisi_acc_vdev->debug_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->saving_migf,
>> + hisi_acc_vdev->debug_migf);
>> hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf);
>> fput(hisi_acc_vdev->saving_migf->filp);
>> hisi_acc_vdev->saving_migf = NULL;
>> @@ -1188,6 +1205,231 @@ 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_io(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;
>> + struct device *dev = vdev->dev;
>> + u64 data;
>> + int ret;
>> +
>> + data = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
>> + dev_info(dev, "debug mailbox val: 0x%llx\n", data);
>> +
>> + ret = qm_wait_dev_not_ready(vf_qm);
>> + if (ret)
>> + dev_err(dev, "VF device not ready!\n");
>
> debugfs has helpers for this, you should use debugfs_print_regs32()
>

I can try it with debugfs_print_regs32().

>> +static int hisi_acc_vf_debug_resume(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;
>> + struct device *dev = vdev->dev;
>> + int ret;
>> +
>> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to save device data!\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = vf_qm_check_match(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to match the VF!\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = vf_qm_load_data(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to recover the VF!\n");
>> + return -EINVAL;
>> + }
>> +
>> + vf_qm_fun_reset(&hisi_acc_vdev->vf_qm);
>> + dev_info(dev, "successful to resume device data!\n");
>> +
>> + return 0;
>> +}
>
> This doesn't seem like it belongs in debugfs at all, please just write
> a test progam using normal vfio ioctls to do these steps and put in
> the kernel selftests directory.
>
>> +static int hisi_acc_vf_debug_save(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;
>> + struct device *dev = vdev->dev;
>> + int ret;
>> +
>> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to save device data!\n");
>> + return -EINVAL;
>> + }
>> + dev_info(dev, "successful to save device data!\n");
>> +
>> + return 0;
>> +}
>
> Ditto, I don't think debugfs should be accessing the device state
> independently of the main FSM.
>

Putting it in debugfs is more free than making it into a kernel
self-test,if we want to use it, we don??t need to configure and
compile it.

Thanks,
Longfang.
> Jason
> .
>

2022-12-17 07:34:21

by liulongfang

[permalink] [raw]
Subject: Re: [PATCH v4 3/5] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

On 2022/12/2 23:21, Jason Gunthorpe Wrote:
> On Fri, Dec 02, 2022 at 05:26:23PM +0800, Longfang Liu wrote:
>> On the debugfs framework of VFIO, register the debug function
>> for the live migration driver of the hisilicon accelerator device.
>>
>> On the basis of the original public debug function, a private debug
>> function is added, so that the single-step debugging function
>> during live migration can be realized.
>>
>> Signed-off-by: Longfang Liu <[email protected]>
>> ---
>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 250 ++++++++++++++++++
>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 9 +
>> drivers/vfio/pci/vfio_pci_debugfs.c | 10 +-
>> 3 files changed, 268 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> index eb18edffbd5f..0f35cde6e8ec 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_pci_debugfs.h"
>>
>> /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
>> static int qm_wait_dev_not_ready(struct hisi_qm *qm)
>> @@ -609,6 +610,18 @@ 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 *src_migf,
>> + struct hisi_acc_vf_migration_file *dst_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);
>> @@ -621,12 +634,16 @@ 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->resuming_migf,
>> + hisi_acc_vdev->debug_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->saving_migf,
>> + hisi_acc_vdev->debug_migf);
>> hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf);
>> fput(hisi_acc_vdev->saving_migf->filp);
>> hisi_acc_vdev->saving_migf = NULL;
>> @@ -1188,6 +1205,231 @@ 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_io(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;
>> + struct device *dev = vdev->dev;
>> + u64 data;
>> + int ret;
>> +
>> + data = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
>> + dev_info(dev, "debug mailbox val: 0x%llx\n", data);
>> +
>> + ret = qm_wait_dev_not_ready(vf_qm);
>> + if (ret)
>> + dev_err(dev, "VF device not ready!\n");
>
> debugfs has helpers for this, you should use debugfs_print_regs32()
>

I analyzed it, and there is no need to replace it here, because it is
a subtype of the "debug" file operation, not an independent debugfs
file operation.

Thanks,
Longfang.

>> +static int hisi_acc_vf_debug_resume(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;
>> + struct device *dev = vdev->dev;
>> + int ret;
>> +
>> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to save device data!\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = vf_qm_check_match(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to match the VF!\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = vf_qm_load_data(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to recover the VF!\n");
>> + return -EINVAL;
>> + }
>> +
>> + vf_qm_fun_reset(&hisi_acc_vdev->vf_qm);
>> + dev_info(dev, "successful to resume device data!\n");
>> +
>> + return 0;
>> +}
>
> This doesn't seem like it belongs in debugfs at all, please just write
> a test progam using normal vfio ioctls to do these steps and put in
> the kernel selftests directory.
>
>> +static int hisi_acc_vf_debug_save(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;
>> + struct device *dev = vdev->dev;
>> + int ret;
>> +
>> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to save device data!\n");
>> + return -EINVAL;
>> + }
>> + dev_info(dev, "successful to save device data!\n");
>> +
>> + return 0;
>> +}
>
> Ditto, I don't think debugfs should be accessing the device state
> independently of the main FSM.
>
> Jason
> .
>