Hi Paolo, On Thu, Apr 29, 2021 at 3:37 PM Jing Zhang <jingzhangos@xxxxxxxxxx> 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 common > * 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. > > --- > > * v3 -> v4 > - Rebase to kvm/queue, commit 9f242010c3b4 ("KVM: avoid "deadlock" > between install_new_memslots and MMU notifier") > - Use C-stype comments in the whole patch > - Fix wrong count for x86 VCPU stats descriptors > - Fix KVM stats data size counting and validity check in selftest > > * v2 -> v3 > - Rebase to kvm/queue, commit edf408f5257b ("KVM: avoid "deadlock" > between install_new_memslots and MMU notifier") > - Resolve some nitpicks about format > > * v1 -> v2 > - Use ARRAY_SIZE to count the number of stats descriptors > - Fix missing `size` field initialization in macro STATS_DESC > > [1] https://lore.kernel.org/kvm/20210402224359.2297157-1-jingzhangos@xxxxxxxxxx > [2] https://lore.kernel.org/kvm/20210415151741.1607806-1-jingzhangos@xxxxxxxxxx > [3] https://lore.kernel.org/kvm/20210423181727.596466-1-jingzhangos@xxxxxxxxxx > > --- > > Jing Zhang (4): > KVM: stats: Separate common stats from architecture specific ones > KVM: stats: Add fd-based API to read binary stats data > KVM: stats: Add documentation for statistics data binary interface > KVM: selftests: Add selftest for KVM statistics data binary interface > > Documentation/virt/kvm/api.rst | 171 ++++++++ > arch/arm64/include/asm/kvm_host.h | 9 +- > arch/arm64/kvm/guest.c | 42 +- > arch/mips/include/asm/kvm_host.h | 9 +- > arch/mips/kvm/mips.c | 67 ++- > arch/powerpc/include/asm/kvm_host.h | 9 +- > arch/powerpc/kvm/book3s.c | 68 +++- > arch/powerpc/kvm/book3s_hv.c | 12 +- > arch/powerpc/kvm/book3s_pr.c | 2 +- > arch/powerpc/kvm/book3s_pr_papr.c | 2 +- > arch/powerpc/kvm/booke.c | 63 ++- > arch/s390/include/asm/kvm_host.h | 9 +- > arch/s390/kvm/kvm-s390.c | 133 +++++- > arch/x86/include/asm/kvm_host.h | 9 +- > arch/x86/kvm/x86.c | 71 +++- > include/linux/kvm_host.h | 132 +++++- > include/linux/kvm_types.h | 12 + > include/uapi/linux/kvm.h | 50 +++ > tools/testing/selftests/kvm/.gitignore | 1 + > tools/testing/selftests/kvm/Makefile | 3 + > .../testing/selftests/kvm/include/kvm_util.h | 3 + > .../selftests/kvm/kvm_bin_form_stats.c | 380 ++++++++++++++++++ > tools/testing/selftests/kvm/lib/kvm_util.c | 11 + > virt/kvm/kvm_main.c | 237 ++++++++++- > 24 files changed, 1415 insertions(+), 90 deletions(-) > create mode 100644 tools/testing/selftests/kvm/kvm_bin_form_stats.c > > > base-commit: 9f242010c3b46e63bc62f08fff42cef992d3801b > -- > 2.31.1.527.g47e6f16901-goog > Do I need to send another version for this? Thanks, Jing