| Message ID | 20221113163832.3154370-6-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: PMU: Fixing chained events, and PMUv3p5 support | expand |
On Sun, Nov 13, 2022 at 8:38 AM Marc Zyngier <maz@kernel.org> wrote: > > For 64bit counters that overflow on a 32bit boundary, make > sure we only check the bottom 32bit to generate a CHAIN event. > > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > arch/arm64/kvm/pmu-emul.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c > index d050143326b5..9e6bc7edc4de 100644 > --- a/arch/arm64/kvm/pmu-emul.c > +++ b/arch/arm64/kvm/pmu-emul.c > @@ -417,7 +417,8 @@ static void kvm_pmu_counter_increment(struct kvm_vcpu *vcpu, > reg = lower_32_bits(reg); > __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg; > > - if (reg) /* No overflow? move on */ > + /* No overflow? move on */ > + if (kvm_pmu_idx_has_64bit_overflow(vcpu, i) ? reg : lower_32_bits(reg)) A few lines up, the 'reg' is unconditionally updated with "lower_32_bits(reg)". So, the change initially confused me (until I checked the following patch). IMHO it might be more clear if this patch and the next patch are folded into one patch. Anyway: Reviewed-by: Reiji Watanabe <reijiw@google.com> Thank you, Reiji > continue; > > /* Mark overflow */ > -- > 2.34.1 >
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index d050143326b5..9e6bc7edc4de 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -417,7 +417,8 @@ static void kvm_pmu_counter_increment(struct kvm_vcpu *vcpu, reg = lower_32_bits(reg); __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg; - if (reg) /* No overflow? move on */ + /* No overflow? move on */ + if (kvm_pmu_idx_has_64bit_overflow(vcpu, i) ? reg : lower_32_bits(reg)) continue; /* Mark overflow */
For 64bit counters that overflow on a 32bit boundary, make sure we only check the bottom 32bit to generate a CHAIN event. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kvm/pmu-emul.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)