Re: [PATCH 0/4] Remove duplicated stats definitions for debugfs

On Mon, Jun 14, 2021 at 4:53 AM Paolo Bonzini [off-list ref] wrote:

On 14/06/21 04:53, Jing Zhang wrote:

quoted

This is a follow-up patchset to binary stats interface patchset as below:
https://lore.kernel.org/kvm/20210611124624.1404010-1-jingzhangos@google.com (local)

This patchset contains a commit to fix some missing stats and add static
check to make sure we have the right number of stats descriptors and add an
'offset' field in stats descriptor to make sure the or order of stats
descriptors is not relevant to the order of stats in vm/vcpu stats
structure. This will totally avoid the possibility of missing stats and
mismatched stats definitions.

The binary stats interface defines stats in another array of descriptors,
while the original stats debugfs interface uses array of kvm_stats_debugfs
item. To remove the duplicated stats definition, this patchset would
utilize only the stats descriptors to provide stats information to debugfs
interface. This patchset adds a 'mode' flag to support the read/write mode
of stats, which can be used to indicate the file permission of debugfs
stats files. It removes the usage of kvm_stats_debugfs_item and all the
debugfs_entries defined in all archs.

The patch also fixes an issue that read only stats could be cleared in
global level, though not permitted in VM level in the original debugfs
code.

Thanks for putting this together quickly.  I think we can drop the mode,
see the suggestion in patch 2.

It's probably best to fold the v8 for the stats functionality, these
patches (squashed appropriately) and Fuad's remars in a single posting.
  But I'm quite confident that it can make it in 5.14.

Paolo

Thanks. Will drop the mode, squash stats functionality with v8 and fold them
in another single posting (v9).

Jing