[PATCH 0/3] Add perf event support for guest VM

[Bibo Mao]

>From perf pmu interrupt is normal IRQ rather than NMI, so code cannot be
profiled if interrupt is disabled. However it is possible to profile
guest kernel in this situation from host side, profile result is more
accurate from host than that from guest.

Perf event support for guest VM is added here, and the below is the
example:
perf kvm --host --guest --guestkallsyms=guest-kallsyms
     --guestmodules=guest-modules  top

Overhead  Shared Object               Symbol
  20.02%  [guest.kernel]              [g] __arch_cpu_idle
  16.74%  [guest.kernel]              [g] queued_spin_lock_slowpath
  10.05%  [kernel]                    [k] __arch_cpu_idle
   2.00%  [guest.kernel]              [g] clear_page
   1.62%  [guest.kernel]              [g] copy_page
   1.50%  [guest.kernel]              [g] next_uptodate_folio
   1.41%  [guest.kernel]              [g] queued_write_lock_slowpath
   1.41%  [guest.kernel]              [g] unmap_page_range
   1.36%  [guest.kernel]              [g] mod_objcg_state
   1.30%  [guest.kernel]              [g] osq_lock
   1.28%  [guest.kernel]              [g] __slab_free
   0.98%  [guest.kernel]              [g] copy_page_range

Bibo Mao (3):
  LoongArch: KVM: Add stub for kvm_arch_vcpu_preempted_in_kernel
  LoongArch: KVM: Implement arch specified functions for guest perf
  LoongArch: KVM: Register perf callback for guest

 arch/loongarch/include/asm/kvm_host.h |  2 ++
 arch/loongarch/kvm/Kconfig            |  1 +
 arch/loongarch/kvm/main.c             |  2 ++
 arch/loongarch/kvm/vcpu.c             | 31 +++++++++++++++++++++++++++
 4 files changed, 36 insertions(+)


base-commit: 2408a807bfc3f738850ef5ad5e3fd59d66168996
-- 
2.39.3