2202844e44
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 <liulongfang@huawei.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20231106072225.28577-2-liulongfang@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
3.1 KiB
SPDX-License-Identifier: GPL-2.0-only
menuconfig VFIO tristate "VFIO Non-Privileged userspace driver framework" select IOMMU_API depends on IOMMUFD || !IOMMUFD select INTERVAL_TREE select VFIO_GROUP if SPAPR_TCE_IOMMU || IOMMUFD=n select VFIO_DEVICE_CDEV if !VFIO_GROUP select VFIO_CONTAINER if IOMMUFD=n help VFIO provides a framework for secure userspace device drivers. See Documentation/driver-api/vfio.rst for more details.
If you don't know what to do here, say N.
if VFIO config VFIO_DEVICE_CDEV bool "Support for the VFIO cdev /dev/vfio/devices/vfioX" depends on IOMMUFD && !SPAPR_TCE_IOMMU default !VFIO_GROUP help The VFIO device cdev is another way for userspace to get device access. Userspace gets device fd by opening device cdev under /dev/vfio/devices/vfioX, and then bind the device fd with an iommufd to set up secure DMA context for device access. This interface does not support noiommu.
If you don't know what to do here, say N.
config VFIO_GROUP bool "Support for the VFIO group /dev/vfio/$group_id" default y help VFIO group support provides the traditional model for accessing devices through VFIO and is used by the majority of userspace applications and drivers making use of VFIO.
If you don't know what to do here, say Y.
config VFIO_CONTAINER bool "Support for the VFIO container /dev/vfio/vfio" select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64) depends on VFIO_GROUP default y help The VFIO container is the classic interface to VFIO for establishing IOMMU mappings. If N is selected here then IOMMUFD must be used to manage the mappings.
Unless testing IOMMUFD say Y here.
if VFIO_CONTAINER config VFIO_IOMMU_TYPE1 tristate default n
config VFIO_IOMMU_SPAPR_TCE tristate depends on SPAPR_TCE_IOMMU default VFIO endif
config VFIO_NOIOMMU bool "VFIO No-IOMMU support" depends on VFIO_GROUP help VFIO is built on the ability to isolate devices using the IOMMU. Only with an IOMMU can userspace access to DMA capable devices be considered secure. VFIO No-IOMMU mode enables IOMMU groups for devices without IOMMU backing for the purpose of re-using the VFIO infrastructure in a non-secure mode. Use of this mode will result in an unsupportable kernel and will therefore taint the kernel. Device assignment to virtual machines is also not possible with this mode since there is no IOMMU to provide DMA translation.
If you don't know what to do here, say N.
config VFIO_VIRQFD bool 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" source "drivers/vfio/fsl-mc/Kconfig" source "drivers/vfio/cdx/Kconfig" endif
source "virt/lib/Kconfig"