Re: [PATCH v3 0/9] perf/x86: Don't write PEBS_ENABLED on KVM transitions

[Sean Christopherson <seanjc@google.com>]

On Thu, Aug 06, 2026, Sean Christopherson wrote:
> On Fri, May 08, 2026, Sean Christopherson wrote:
> > Sean Christopherson (9):
> >   perf/x86/intel: Ensure guest PEBS path doesn't set unwanted
> >     PERF_GLOBAL_CTRL bits
> >   perf/x86/intel: Don't write PEBS_ENABLED on host<=>guest xfers if CPU
> >     has isolation
> >   perf/x86/intel: Don't context switch DS_AREA (and PEBS config) if PEBS
> >     is unused
> >   perf/x86/intel: Make @data a mandatory param for
> >     intel_guest_get_msrs()
> >   perf/x86/intel: Invert names of intel_ctrl_{guest,host}_mask
> >   perf/x86: KVM: Have perf define a dedicated struct for getting guest
> >     PEBS data
> >   perf/x86/intel: KVM: Handle cross-mapped PEBS PMCs entirely within KVM
> >   KVM: VMX: Drop a redundant pmu->global_ctrl check when processing
> >     pebs_enable
> >   KVM: VMX: Only tell perf to enable PEBS counters for fully enabled
> >     PMCs
> > 
> >  arch/x86/events/core.c            |  5 +-
> >  arch/x86/events/intel/core.c      | 92 +++++++++++++++++++------------
> >  arch/x86/events/intel/lbr.c       |  2 +-
> >  arch/x86/events/perf_event.h      |  7 ++-
> >  arch/x86/include/asm/kvm_host.h   |  9 ---
> >  arch/x86/include/asm/perf_event.h | 11 +++-
> >  arch/x86/kvm/vmx/pmu_intel.c      | 28 +++++++---
> >  arch/x86/kvm/vmx/vmx.c            | 10 ++--
> >  arch/x86/kvm/vmx/vmx.h            | 15 ++++-
> >  9 files changed, 114 insertions(+), 65 deletions(-)
> 
> Ping.  This still applies on Linus' tree and against tip/master.

Ping again.  This fixes a real issue and IMO provides much-needed improvements
for the KVM<=>perf APIs.