Add a debugfs function to the migration driver in VFIO to provide
a step-by-step debugfs information for the migration driver.
Changes v18 -> v19
maintainers add a patch.
Changes v17 -> v18
Replace seq_printf() with seq_puts().
Changes v16 -> v17
Add separate VFIO_DEBUGFS Kconfig entries.
Changes v15 -> v16
Update the calling order of functions to maintain symmetry
Changes v14 -> v15
Update the output status value of live migration.
Changes v13 -> v14
Split the patchset and keep the vfio debugfs frame.
Changes v12 -> v13
Solve the problem of open and close competition to debugfs.
Changes v11 -> v12
Update loading conditions of vfio debugfs.
Changes v10 -> v11
Delete the device restore function in debugfs.
Changes v9 -> v10
Update the debugfs file of the live migration driver.
Changes v8 -> v9
Update the debugfs directory structure of vfio.
Changes v7 -> v8
Add support for platform devices.
Changes v6 -> v7
Fix some code style issues.
Changes v5 -> v6
Control the creation of debugfs through the CONFIG_DEBUG_FS.
Changes v4 -> v5
Remove the newly added vfio_migration_ops and use seq_printf
to optimize the implementation of debugfs.
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 (3):
vfio/migration: Add debugfs to live migration driver
Documentation: add debugfs description for vfio
MAINTAINERS: Update the maintenance directory of vfio driver
Documentation/ABI/testing/debugfs-vfio | 25 +++++++
MAINTAINERS | 1 +
drivers/vfio/Kconfig | 10 +++
drivers/vfio/Makefile | 1 +
drivers/vfio/debugfs.c | 90 ++++++++++++++++++++++++++
drivers/vfio/vfio.h | 14 ++++
drivers/vfio/vfio_main.c | 4 ++
include/linux/vfio.h | 7 ++
include/uapi/linux/vfio.h | 1 +
9 files changed, 153 insertions(+)
create mode 100644 Documentation/ABI/testing/debugfs-vfio
create mode 100644 drivers/vfio/debugfs.c
--
2.24.0
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 vfio_dev| |dst vfio_dev|
+--+---------+ +--+---------+
| ^ | ^
| | | |
v | | |
+-----------+----+ +-----------+----+
|src dev debugfs | |dst dev debugfs |
+----------------+ +----------------+
The entire debugfs directory will be based on the definition of
the CONFIG_DEBUG_FS macro. If this macro is not enabled, the
interfaces in vfio.h will be empty definitions, and the creation
and initialization of the debugfs directory will not be executed.
vfio
|
+---<dev_name1>
| +---migration
| +--state
|
+---<dev_name2>
+---migration
+--state
debugfs will create a public root directory "vfio" file.
then create a dev_name() file for each live migration device.
First, create a unified state acquisition file of "migration"
in this device directory.
Then, create a public live migration state lookup file "state".
Signed-off-by: Longfang Liu <[email protected]>
Reviewed-by: Cedric Le Goater <[email protected]>
---
drivers/vfio/Kconfig | 10 +++++
drivers/vfio/Makefile | 1 +
drivers/vfio/debugfs.c | 90 +++++++++++++++++++++++++++++++++++++++
drivers/vfio/vfio.h | 14 ++++++
drivers/vfio/vfio_main.c | 4 ++
include/linux/vfio.h | 7 +++
include/uapi/linux/vfio.h | 1 +
7 files changed, 127 insertions(+)
create mode 100644 drivers/vfio/debugfs.c
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
index 6bda6dbb4878..ceae52fd7586 100644
--- a/drivers/vfio/Kconfig
+++ b/drivers/vfio/Kconfig
@@ -80,6 +80,16 @@ config VFIO_VIRQFD
select EVENTFD
default n
+config VFIO_DEBUGFS
+ bool "Export VFIO internals in DebugFS"
+ depends on DEBUG_FS
+ help
+ Allows exposure of VFIO device internals. This option enables
+ the use of debugfs by VFIO drivers as required. The device can
+ cause the VFIO code create a top-level debug/vfio directory
+ during initialization, and then populate a subdirectory with
+ entries as required.
+
source "drivers/vfio/pci/Kconfig"
source "drivers/vfio/platform/Kconfig"
source "drivers/vfio/mdev/Kconfig"
diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile
index c82ea032d352..d43a699d55b1 100644
--- a/drivers/vfio/Makefile
+++ b/drivers/vfio/Makefile
@@ -8,6 +8,7 @@ vfio-$(CONFIG_VFIO_GROUP) += group.o
vfio-$(CONFIG_IOMMUFD) += iommufd.o
vfio-$(CONFIG_VFIO_CONTAINER) += container.o
vfio-$(CONFIG_VFIO_VIRQFD) += virqfd.o
+vfio-$(CONFIG_VFIO_DEBUGFS) += debugfs.o
obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o
obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o
diff --git a/drivers/vfio/debugfs.c b/drivers/vfio/debugfs.c
new file mode 100644
index 000000000000..9f02ae15e084
--- /dev/null
+++ b/drivers/vfio/debugfs.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023, HiSilicon Ltd.
+ */
+
+#include <linux/device.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/vfio.h>
+#include "vfio.h"
+
+static struct dentry *vfio_debugfs_root;
+
+static int vfio_device_state_read(struct seq_file *seq, void *data)
+{
+ struct device *vf_dev = seq->private;
+ struct vfio_device *vdev = container_of(vf_dev, struct vfio_device, device);
+ enum vfio_device_mig_state state;
+ int ret;
+
+ BUILD_BUG_ON(VFIO_DEVICE_STATE_NR !=
+ VFIO_DEVICE_STATE_PRE_COPY_P2P + 1);
+
+ ret = vdev->mig_ops->migration_get_state(vdev, &state);
+ if (ret)
+ return -EINVAL;
+
+ switch (state) {
+ case VFIO_DEVICE_STATE_ERROR:
+ seq_puts(seq, "ERROR\n");
+ break;
+ case VFIO_DEVICE_STATE_STOP:
+ seq_puts(seq, "STOP\n");
+ break;
+ case VFIO_DEVICE_STATE_RUNNING:
+ seq_puts(seq, "RUNNING\n");
+ break;
+ case VFIO_DEVICE_STATE_STOP_COPY:
+ seq_puts(seq, "STOP_COPY\n");
+ break;
+ case VFIO_DEVICE_STATE_RESUMING:
+ seq_puts(seq, "RESUMING\n");
+ break;
+ case VFIO_DEVICE_STATE_RUNNING_P2P:
+ seq_puts(seq, "RUNNING_P2P\n");
+ break;
+ case VFIO_DEVICE_STATE_PRE_COPY:
+ seq_puts(seq, "PRE_COPY\n");
+ break;
+ case VFIO_DEVICE_STATE_PRE_COPY_P2P:
+ seq_puts(seq, "PRE_COPY_P2P\n");
+ break;
+ default:
+ seq_puts(seq, "Invalid\n");
+ }
+
+ return 0;
+}
+
+void vfio_device_debugfs_init(struct vfio_device *vdev)
+{
+ struct device *dev = &vdev->device;
+
+ vdev->debug_root = debugfs_create_dir(dev_name(vdev->dev), vfio_debugfs_root);
+
+ if (vdev->mig_ops) {
+ struct dentry *vfio_dev_migration = NULL;
+
+ vfio_dev_migration = debugfs_create_dir("migration", vdev->debug_root);
+ debugfs_create_devm_seqfile(dev, "state", vfio_dev_migration,
+ vfio_device_state_read);
+ }
+}
+
+void vfio_device_debugfs_exit(struct vfio_device *vdev)
+{
+ debugfs_remove_recursive(vdev->debug_root);
+}
+
+void vfio_debugfs_create_root(void)
+{
+ vfio_debugfs_root = debugfs_create_dir("vfio", NULL);
+}
+
+void vfio_debugfs_remove_root(void)
+{
+ debugfs_remove_recursive(vfio_debugfs_root);
+ vfio_debugfs_root = NULL;
+}
+
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 307e3f29b527..bde84ad344e5 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -448,4 +448,18 @@ static inline void vfio_device_put_kvm(struct vfio_device *device)
}
#endif
+#ifdef CONFIG_VFIO_DEBUGFS
+void vfio_debugfs_create_root(void);
+void vfio_debugfs_remove_root(void);
+
+void vfio_device_debugfs_init(struct vfio_device *vdev);
+void vfio_device_debugfs_exit(struct vfio_device *vdev);
+#else
+static inline void vfio_debugfs_create_root(void) { }
+static inline void vfio_debugfs_remove_root(void) { }
+
+static inline void vfio_device_debugfs_init(struct vfio_device *vdev) { }
+static inline void vfio_device_debugfs_exit(struct vfio_device *vdev) { }
+#endif /* CONFIG_VFIO_DEBUGFS */
+
#endif
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index e31e1952d7b8..94f02b6891ac 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -311,6 +311,7 @@ static int __vfio_register_dev(struct vfio_device *device,
refcount_set(&device->refcount, 1);
vfio_device_group_register(device);
+ vfio_device_debugfs_init(device);
return 0;
err_out:
@@ -378,6 +379,7 @@ void vfio_unregister_group_dev(struct vfio_device *device)
}
}
+ vfio_device_debugfs_exit(device);
/* Balances vfio_device_set_group in register path */
vfio_device_remove_group(device);
}
@@ -1676,6 +1678,7 @@ static int __init vfio_init(void)
if (ret)
goto err_alloc_dev_chrdev;
+ vfio_debugfs_create_root();
pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
return 0;
@@ -1691,6 +1694,7 @@ static int __init vfio_init(void)
static void __exit vfio_cleanup(void)
{
+ vfio_debugfs_remove_root();
ida_destroy(&vfio.device_ida);
vfio_cdev_cleanup();
class_destroy(vfio.device_class);
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 454e9295970c..769d7af86225 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -69,6 +69,13 @@ struct vfio_device {
u8 iommufd_attached:1;
#endif
u8 cdev_opened:1;
+#ifdef CONFIG_DEBUG_FS
+ /*
+ * debug_root is a static property of the vfio_device
+ * which must be set prior to registering the vfio_device.
+ */
+ struct dentry *debug_root;
+#endif
};
/**
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 7f5fb010226d..2b68e6cdf190 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -1219,6 +1219,7 @@ enum vfio_device_mig_state {
VFIO_DEVICE_STATE_RUNNING_P2P = 5,
VFIO_DEVICE_STATE_PRE_COPY = 6,
VFIO_DEVICE_STATE_PRE_COPY_P2P = 7,
+ VFIO_DEVICE_STATE_NR,
};
/**
--
2.24.0
After adding the debugfs function to the vfio driver,
a new debugfs-vfio file was added.
Signed-off-by: Longfang Liu <[email protected]>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index b19995690904..b3659ec29389 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22590,6 +22590,7 @@ M: Alex Williamson <[email protected]>
L: [email protected]
S: Maintained
T: git https://github.com/awilliam/linux-vfio.git
+F: Documentation/ABI/testing/debugfs-vfio
F: Documentation/ABI/testing/sysfs-devices-vfio-dev
F: Documentation/driver-api/vfio.rst
F: drivers/vfio/
--
2.24.0
Add an 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]>
Reviewed-by: Cedric Le Goater <[email protected]>
---
Documentation/ABI/testing/debugfs-vfio | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
create mode 100644 Documentation/ABI/testing/debugfs-vfio
diff --git a/Documentation/ABI/testing/debugfs-vfio b/Documentation/ABI/testing/debugfs-vfio
new file mode 100644
index 000000000000..210eca135979
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-vfio
@@ -0,0 +1,25 @@
+What: /sys/kernel/debug/vfio
+Date: Nov 2023
+KernelVersion: 6.7
+Contact: Longfang Liu <[email protected]>
+Description: This debugfs file directory is used for debugging
+ of vfio devices, it's a common directory for all vfio devices.
+ Vfio core will create a device subdirectory under this
+ directory.
+
+What: /sys/kernel/debug/vfio/<device>/migration
+Date: Nov 2023
+KernelVersion: 6.7
+Contact: Longfang Liu <[email protected]>
+Description: This debugfs file directory is used for debugging
+ of vfio devices that support live migration.
+ The debugfs of each vfio device that supports live migration
+ could be created under this directory.
+
+What: /sys/kernel/debug/vfio/<device>/migration/state
+Date: Nov 2023
+KernelVersion: 6.7
+Contact: Longfang Liu <[email protected]>
+Description: Read the live migration status of the vfio device.
+ The contents of the state file reflects the migration state
+ relative to those defined in the vfio_device_mig_state enum
--
2.24.0
On 2023/11/6 15:22, Longfang Liu wrote:
> Add a debugfs function to the migration driver in VFIO to provide
> a step-by-step debugfs information for the migration driver.
>
> Changes v18 -> v19
> maintainers add a patch.
>
> Changes v17 -> v18
> Replace seq_printf() with seq_puts().
>
> Changes v16 -> v17
> Add separate VFIO_DEBUGFS Kconfig entries.
>
> Changes v15 -> v16
> Update the calling order of functions to maintain symmetry
>
> Changes v14 -> v15
> Update the output status value of live migration.
>
> Changes v13 -> v14
> Split the patchset and keep the vfio debugfs frame.
>
> Changes v12 -> v13
> Solve the problem of open and close competition to debugfs.
>
> Changes v11 -> v12
> Update loading conditions of vfio debugfs.
>
> Changes v10 -> v11
> Delete the device restore function in debugfs.
>
> Changes v9 -> v10
> Update the debugfs file of the live migration driver.
>
> Changes v8 -> v9
> Update the debugfs directory structure of vfio.
>
> Changes v7 -> v8
> Add support for platform devices.
>
> Changes v6 -> v7
> Fix some code style issues.
>
> Changes v5 -> v6
> Control the creation of debugfs through the CONFIG_DEBUG_FS.
>
> Changes v4 -> v5
> Remove the newly added vfio_migration_ops and use seq_printf
> to optimize the implementation of debugfs.
>
> 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 (3):
> vfio/migration: Add debugfs to live migration driver
> Documentation: add debugfs description for vfio
> MAINTAINERS: Update the maintenance directory of vfio driver
>
> Documentation/ABI/testing/debugfs-vfio | 25 +++++++
> MAINTAINERS | 1 +
> drivers/vfio/Kconfig | 10 +++
> drivers/vfio/Makefile | 1 +
> drivers/vfio/debugfs.c | 90 ++++++++++++++++++++++++++
> drivers/vfio/vfio.h | 14 ++++
> drivers/vfio/vfio_main.c | 4 ++
> include/linux/vfio.h | 7 ++
> include/uapi/linux/vfio.h | 1 +
> 9 files changed, 153 insertions(+)
> create mode 100644 Documentation/ABI/testing/debugfs-vfio
> create mode 100644 drivers/vfio/debugfs.c
>
Hi, Alex:
Please review this patchset.
Thanks.
Longfang.
On Mon, 6 Nov 2023 15:22:22 +0800
Longfang Liu <[email protected]> wrote:
> Add a debugfs function to the migration driver in VFIO to provide
> a step-by-step debugfs information for the migration driver.
>
> Changes v18 -> v19
> maintainers add a patch.
>
> Changes v17 -> v18
> Replace seq_printf() with seq_puts().
>
> Changes v16 -> v17
> Add separate VFIO_DEBUGFS Kconfig entries.
>
> Changes v15 -> v16
> Update the calling order of functions to maintain symmetry
>
> Changes v14 -> v15
> Update the output status value of live migration.
>
> Changes v13 -> v14
> Split the patchset and keep the vfio debugfs frame.
>
> Changes v12 -> v13
> Solve the problem of open and close competition to debugfs.
>
> Changes v11 -> v12
> Update loading conditions of vfio debugfs.
>
> Changes v10 -> v11
> Delete the device restore function in debugfs.
>
> Changes v9 -> v10
> Update the debugfs file of the live migration driver.
>
> Changes v8 -> v9
> Update the debugfs directory structure of vfio.
>
> Changes v7 -> v8
> Add support for platform devices.
>
> Changes v6 -> v7
> Fix some code style issues.
>
> Changes v5 -> v6
> Control the creation of debugfs through the CONFIG_DEBUG_FS.
>
> Changes v4 -> v5
> Remove the newly added vfio_migration_ops and use seq_printf
> to optimize the implementation of debugfs.
>
> 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 (3):
> vfio/migration: Add debugfs to live migration driver
> Documentation: add debugfs description for vfio
> MAINTAINERS: Update the maintenance directory of vfio driver
>
> Documentation/ABI/testing/debugfs-vfio | 25 +++++++
> MAINTAINERS | 1 +
> drivers/vfio/Kconfig | 10 +++
> drivers/vfio/Makefile | 1 +
> drivers/vfio/debugfs.c | 90 ++++++++++++++++++++++++++
> drivers/vfio/vfio.h | 14 ++++
> drivers/vfio/vfio_main.c | 4 ++
> include/linux/vfio.h | 7 ++
> include/uapi/linux/vfio.h | 1 +
> 9 files changed, 153 insertions(+)
> create mode 100644 Documentation/ABI/testing/debugfs-vfio
> create mode 100644 drivers/vfio/debugfs.c
>
Applied to vfio next branch for v6.8. I resolved some whitespace
issues and updated the date and kernel release version in the
Documentation as well. Thanks,
Alex
On 2023/12/5 8:00, Alex Williamson wrote:
> On Mon, 6 Nov 2023 15:22:22 +0800
> Longfang Liu <[email protected]> wrote:
>
>> Add a debugfs function to the migration driver in VFIO to provide
>> a step-by-step debugfs information for the migration driver.
>>
>> Changes v18 -> v19
>> maintainers add a patch.
>>
>> Changes v17 -> v18
>> Replace seq_printf() with seq_puts().
>>
>> Changes v16 -> v17
>> Add separate VFIO_DEBUGFS Kconfig entries.
>>
>> Changes v15 -> v16
>> Update the calling order of functions to maintain symmetry
>>
>> Changes v14 -> v15
>> Update the output status value of live migration.
>>
>> Changes v13 -> v14
>> Split the patchset and keep the vfio debugfs frame.
>>
>> Changes v12 -> v13
>> Solve the problem of open and close competition to debugfs.
>>
>> Changes v11 -> v12
>> Update loading conditions of vfio debugfs.
>>
>> Changes v10 -> v11
>> Delete the device restore function in debugfs.
>>
>> Changes v9 -> v10
>> Update the debugfs file of the live migration driver.
>>
>> Changes v8 -> v9
>> Update the debugfs directory structure of vfio.
>>
>> Changes v7 -> v8
>> Add support for platform devices.
>>
>> Changes v6 -> v7
>> Fix some code style issues.
>>
>> Changes v5 -> v6
>> Control the creation of debugfs through the CONFIG_DEBUG_FS.
>>
>> Changes v4 -> v5
>> Remove the newly added vfio_migration_ops and use seq_printf
>> to optimize the implementation of debugfs.
>>
>> 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 (3):
>> vfio/migration: Add debugfs to live migration driver
>> Documentation: add debugfs description for vfio
>> MAINTAINERS: Update the maintenance directory of vfio driver
>>
>> Documentation/ABI/testing/debugfs-vfio | 25 +++++++
>> MAINTAINERS | 1 +
>> drivers/vfio/Kconfig | 10 +++
>> drivers/vfio/Makefile | 1 +
>> drivers/vfio/debugfs.c | 90 ++++++++++++++++++++++++++
>> drivers/vfio/vfio.h | 14 ++++
>> drivers/vfio/vfio_main.c | 4 ++
>> include/linux/vfio.h | 7 ++
>> include/uapi/linux/vfio.h | 1 +
>> 9 files changed, 153 insertions(+)
>> create mode 100644 Documentation/ABI/testing/debugfs-vfio
>> create mode 100644 drivers/vfio/debugfs.c
>>
>
> Applied to vfio next branch for v6.8. I resolved some whitespace
> issues and updated the date and kernel release version in the
> Documentation as well. Thanks,
>
OK, thank you very much!
Longfang.
> Alex
>
> .
>