On 11/06/21 14:46, Jing Zhang wrote:

This patchset provides a file descriptor for every VM and VCPU to read
KVM statistics data in binary format.
It is meant to provide a lightweight, flexible, scalable and efficient
lock-free solution for user space telemetry applications to pull the
statistics data periodically for large scale systems. The pulling
frequency could be as high as a few times per second.
In this patchset, every statistics data are treated to have some
attributes as below:
   * architecture dependent or generic
   * VM statistics data or VCPU statistics data
   * type: cumulative, instantaneous,
   * unit: none for simple counter, nanosecond, microsecond,
     millisecond, second, Byte, KiByte, MiByte, GiByte. Clock Cycles
Since no lock/synchronization is used, the consistency between all
the statistics data is not guaranteed. That means not all statistics
data are read out at the exact same time, since the statistics date
are still being updated by KVM subsystems while they are read out.

The binary interface itself looks good.  Can you do a follow-up patch to 
remove struct kvm_stats_debugfs_item and avoid the duplication?  I'd 
rather have that too before committing the code.

Thanks,

Paolo