KVM: x86/pmu: Add pmc->intr to refactor kvm_perf_overflow{_intr}()

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Depending on whether intr should be triggered or not, KVM registers
two different event overflow callbacks in the perf_event context.

The code skeleton of these two functions is very similar, so
the pmc->intr can be stored into pmc from pmc_reprogram_counter()
which provides smaller instructions footprint against the
u-architecture branch predictor.

The __kvm_perf_overflow() can be called in non-nmi contexts
and a flag is needed to distinguish the caller context and thus
avoid a check on kvm_is_in_guest(), otherwise we might get
warnings from suspicious RCU or check_preemption_disabled().

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20211130074221.93635-5-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Like Xu 2021-11-30 15:42:19 +08:00 • committed by Paolo Bonzini

parent 6ed1298eb0

commit 40ccb96d54

2 changed files with 29 additions and 30 deletions

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arch/x86/include/asm/kvm_host.h

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arch/x86/kvm/pmu.c

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