mbox series

[0/5] KVM: Refactor KVM stats macros to allow custom names

Message ID 20230118175300.790835-1-dmatlack@google.com (mailing list archive)
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Series KVM: Refactor KVM stats macros to allow custom names | expand

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David Matlack Jan. 18, 2023, 5:52 p.m. UTC 
This series refactors the KVM stats macros to allow specifying custom
names, e.g.

  STATS_DESC_COUNTER(VM, foo),
  __STATS_DESC_COUNTER(VM, bar, "custom_name"),

Custom name makes it possible to decouple the userspace-visible stat
names from their internal representation in C. This can allow future
commits to refactor the various stats structs without impacting
userspace tools that read KVM stats.

This also allows stats to be stored in data structures such as arrays,
without needing unions to access specific stats. Case in point, the last
patch in this series removes the pages_{4k,2m,1g} union, which is a
useful cleanup to prepare for the Common MMU [1].

And for full transparency, another motivation for this series it that at
Google we have several out-of-tree stats that use arrays. Custom name
support is something we added internally and it reduces our technical
debt to get the support merged upstream.

Link: https://lore.kernel.org/kvm/20221208193857.4090582-1-dmatlack@google.com/

David Matlack (5):
  KVM: Consistently use "stat" name in stats macros
  KVM: Spell out parameter names in stats macros
  KVM: Fix indentation in stats macros
  KVM: Allow custom names for stats
  KVM: x86: Drop union for pages_{4k,2m,1g} stats

 arch/x86/include/asm/kvm_host.h |   9 +-
 arch/x86/kvm/x86.c              |   6 +-
 include/linux/kvm_host.h        | 170 +++++++++++++++++++-------------
 3 files changed, 107 insertions(+), 78 deletions(-)


base-commit: de60733246ff4545a0483140c1f21426b8d7cb7f
prerequisite-patch-id: 42a76ce7cec240776c21f674e99e893a3a6bee58