On Tue, 2 Apr 2024 11:24:32 +0800 Longfang Liu <liulongfang@xxxxxxxxxx> wrote: > Add a debugfs document description file to help users understand > how to use the hisilicon accelerator live migration driver's > debugfs. > > Update the file paths that need to be maintained in MAINTAINERS > > Signed-off-by: Longfang Liu <liulongfang@xxxxxxxxxx> > --- > .../ABI/testing/debugfs-hisi-migration | 34 +++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 35 insertions(+) > create mode 100644 Documentation/ABI/testing/debugfs-hisi-migration > > diff --git a/Documentation/ABI/testing/debugfs-hisi-migration b/Documentation/ABI/testing/debugfs-hisi-migration > new file mode 100644 > index 000000000000..3d7339276e6f > --- /dev/null > +++ b/Documentation/ABI/testing/debugfs-hisi-migration > @@ -0,0 +1,34 @@ > +What: /sys/kernel/debug/vfio/<device>/migration/hisi_acc/data > +Date: Apr 2024 > +KernelVersion: 6.9 At best 6.10 with a merge window in May. > +Contact: Longfang Liu <liulongfang@xxxxxxxxxx> > +Description: Read the live migration data of the vfio device. > + These data include device status data, queue configuration > + data and some task configuration data. > + The output format of the data is defined by the live > + migration driver. "Dumps the device debug migration buffer, state must first be saved using the 'save' attribute." > + > +What: /sys/kernel/debug/vfio/<device>/migration/hisi_acc/attr > +Date: Apr 2024 > +KernelVersion: 6.9 > +Contact: Longfang Liu <liulongfang@xxxxxxxxxx> > +Description: Read the live migration attributes of the vfio device. > + it include device status attributes and data length attributes > + The output format of the attributes is defined by the live > + migration driver. AFAICT from the previous patch, this attribute is useless. > + > +What: /sys/kernel/debug/vfio/<device>/migration/hisi_acc/cmd_state > +Date: Apr 2024 > +KernelVersion: 6.9 > +Contact: Longfang Liu <liulongfang@xxxxxxxxxx> > +Description: Used to obtain the device command sending and receiving > + channel status. If successful, returns the command value. > + If failed, return error log. > + Seems like it statically returns "OK" plus the actual value. > +What: /sys/kernel/debug/vfio/<device>/migration/hisi_acc/save > +Date: Apr 2024 > +KernelVersion: 6.9 > +Contact: Longfang Liu <liulongfang@xxxxxxxxxx> > +Description: Trigger the Hisilicon accelerator device to perform > + the state saving operation of live migration through the read > + operation, and output the operation log results. These interfaces are confusing, attr and data only work if there has either been a previous save OR the user migration process closed saving or resuming fds in the interim, and the user doesn't know which one they get. Note that debug_migf isn't even discarded between open/close, only cmd and save require the device to be opened by a user, data and attr might continue to return data from some previous user save, resume, or debugfs save. > diff --git a/MAINTAINERS b/MAINTAINERS > index 7625911ec2f1..8c2d13b13273 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -23072,6 +23072,7 @@ M: Longfang Liu <liulongfang@xxxxxxxxxx> > M: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> > L: kvm@xxxxxxxxxxxxxxx > S: Maintained > +F: Documentation/ABI/testing/debugfs-hisi-migration > F: drivers/vfio/pci/hisilicon/ > > VFIO MEDIATED DEVICE DRIVERS
