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| author | Like Xu <like.xu@linux.intel.com> | 2021-02-01 13:10:36 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-04 05:27:25 -0500 |
| commit | e6209a3bef793e8fe29c873a7612023916eaa611 (patch) | |
| tree | b885d145d233977d0b6e5105d5194d5a5a6ad3ab /tools/perf/scripts/python/flamegraph.py | |
| parent | KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation (diff) | |
| download | linux-e6209a3bef793e8fe29c873a7612023916eaa611.tar.gz linux-e6209a3bef793e8fe29c873a7612023916eaa611.zip | |
KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI
The current vPMU only supports Architecture Version 2. According to
Intel SDM "17.4.7 Freezing LBR and Performance Counters on PMI", if
IA32_DEBUGCTL.Freeze_LBR_On_PMI = 1, the LBR is frozen on the virtual
PMI and the KVM would emulate to clear the LBR bit (bit 0) in
IA32_DEBUGCTL. Also, guest needs to re-enable IA32_DEBUGCTL.LBR
to resume recording branches.
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Message-Id: <20210201051039.255478-9-like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tools/perf/scripts/python/flamegraph.py')
0 files changed, 0 insertions, 0 deletions