Hi Haibo, On 8/7/20 10:10 AM, Haibo Xu wrote: > Adds a spe=[on/off] option to enable/disable vSPE support in > guest vCPU. Note this option is only available for "-cpu host" > with KVM mode, and default value is on. > > Signed-off-by: Haibo Xu <haibo...@linaro.org> > --- > target/arm/cpu.c | 28 ++++++++++++++++++++++++++++ > target/arm/cpu.h | 3 +++ > 2 files changed, 31 insertions(+) > > diff --git a/target/arm/cpu.c b/target/arm/cpu.c > index 111579554f..40768b4d19 100644 > --- a/target/arm/cpu.c > +++ b/target/arm/cpu.c > @@ -1122,6 +1122,29 @@ static void arm_set_pmu(Object *obj, bool value, Error > **errp) > cpu->has_pmu = value; > } > > +static bool arm_get_spe(Object *obj, Error **errp) > +{ > + ARMCPU *cpu = ARM_CPU(obj); > + > + return cpu->has_spe; > +} > + > +static void arm_set_spe(Object *obj, bool value, Error **errp) > +{ > + ARMCPU *cpu = ARM_CPU(obj); > + > + if (value) { > + if (kvm_enabled() && !kvm_arm_spe_supported()) { > + error_setg(errp, "'spe' feature not supported by KVM on this > host"); > + return; > + } > + set_feature(&cpu->env, ARM_FEATURE_SPE); > + } else { > + unset_feature(&cpu->env, ARM_FEATURE_SPE); > + } > + cpu->has_spe = value; > +} > + > unsigned int gt_cntfrq_period_ns(ARMCPU *cpu) > { > /* > @@ -1195,6 +1218,11 @@ void arm_cpu_post_init(Object *obj) > object_property_add_bool(obj, "pmu", arm_get_pmu, arm_set_pmu); > } > > + if (arm_feature(&cpu->env, ARM_FEATURE_SPE)) { > + cpu->has_spe = true;
Being a profiling feature, are you sure you want it to be ON by default? I'd expect the opposite, either being turned on via command line at startup or by a management layer at runtime, when someone is ready to record the perf events and analyze them. > + object_property_add_bool(obj, "spe", arm_get_spe, arm_set_spe); > + } > + > /* > * Allow user to turn off VFP and Neon support, but only for TCG -- > * KVM does not currently allow us to lie to the guest about its > diff --git a/target/arm/cpu.h b/target/arm/cpu.h > index 9e8ed423ea..fe0ac14386 100644 > --- a/target/arm/cpu.h > +++ b/target/arm/cpu.h > @@ -822,6 +822,8 @@ struct ARMCPU { > bool has_el3; > /* CPU has PMU (Performance Monitor Unit) */ > bool has_pmu; > + /* CPU has SPE (Statistical Profiling Extension) */ > + bool has_spe; > /* CPU has VFP */ > bool has_vfp; > /* CPU has Neon */ > @@ -1959,6 +1961,7 @@ enum arm_features { > ARM_FEATURE_VBAR, /* has cp15 VBAR */ > ARM_FEATURE_M_SECURITY, /* M profile Security Extension */ > ARM_FEATURE_M_MAIN, /* M profile Main Extension */ > + ARM_FEATURE_SPE, /* has SPE support */ > }; > > static inline int arm_feature(CPUARMState *env, int feature) >