On 10/26/2024 12:16 AM, Chen, Zide wrote:
>
> On 7/31/2024 9:58 PM, Mingwei Zhang wrote:
>> Introduce PMU operator for setting counter overflow. When emulating counter
>> increment, multiple counters could overflow at the same time, i.e., during
>> the execution of the same instruction. In passthrough PMU, having an PMU
>> operator provides convenience to update the PMU global status in one shot
>> with details hidden behind the vendor specific implementation.
> Since neither Intel nor AMD does implement this API, this patch should
> be dropped.
oh, yes.
>
>> Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
>> Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
>> ---
>> arch/x86/include/asm/kvm-x86-pmu-ops.h | 1 +
>> arch/x86/kvm/pmu.h | 1 +
>> arch/x86/kvm/vmx/pmu_intel.c | 5 +++++
>> 3 files changed, 7 insertions(+)
>>
>> diff --git a/arch/x86/include/asm/kvm-x86-pmu-ops.h b/arch/x86/include/asm/kvm-x86-pmu-ops.h
>> index 72ca78df8d2b..bd5b118a5ce5 100644
>> --- a/arch/x86/include/asm/kvm-x86-pmu-ops.h
>> +++ b/arch/x86/include/asm/kvm-x86-pmu-ops.h
>> @@ -28,6 +28,7 @@ KVM_X86_PMU_OP_OPTIONAL(passthrough_pmu_msrs)
>> KVM_X86_PMU_OP_OPTIONAL(save_pmu_context)
>> KVM_X86_PMU_OP_OPTIONAL(restore_pmu_context)
>> KVM_X86_PMU_OP_OPTIONAL(incr_counter)
>> +KVM_X86_PMU_OP_OPTIONAL(set_overflow)
>>
>> #undef KVM_X86_PMU_OP
>> #undef KVM_X86_PMU_OP_OPTIONAL
>> diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
>> index 325f17673a00..78a7f0c5f3ba 100644
>> --- a/arch/x86/kvm/pmu.h
>> +++ b/arch/x86/kvm/pmu.h
>> @@ -45,6 +45,7 @@ struct kvm_pmu_ops {
>> void (*save_pmu_context)(struct kvm_vcpu *vcpu);
>> void (*restore_pmu_context)(struct kvm_vcpu *vcpu);
>> bool (*incr_counter)(struct kvm_pmc *pmc);
>> + void (*set_overflow)(struct kvm_vcpu *vcpu);
>>
>> const u64 EVENTSEL_EVENT;
>> const int MAX_NR_GP_COUNTERS;
>> diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
>> index 42af2404bdb9..2d46c911f0b7 100644
>> --- a/arch/x86/kvm/vmx/pmu_intel.c
>> +++ b/arch/x86/kvm/vmx/pmu_intel.c
>> @@ -881,6 +881,10 @@ static void intel_restore_guest_pmu_context(struct kvm_vcpu *vcpu)
>> wrmsrl(MSR_CORE_PERF_FIXED_CTR_CTRL, pmu->fixed_ctr_ctrl_hw);
>> }
>>
>> +static void intel_set_overflow(struct kvm_vcpu *vcpu)
>> +{
>> +}
>> +
>> struct kvm_pmu_ops intel_pmu_ops __initdata = {
>> .rdpmc_ecx_to_pmc = intel_rdpmc_ecx_to_pmc,
>> .msr_idx_to_pmc = intel_msr_idx_to_pmc,
>> @@ -897,6 +901,7 @@ struct kvm_pmu_ops intel_pmu_ops __initdata = {
>> .save_pmu_context = intel_save_guest_pmu_context,
>> .restore_pmu_context = intel_restore_guest_pmu_context,
>> .incr_counter = intel_incr_counter,
>> + .set_overflow = intel_set_overflow,
>> .EVENTSEL_EVENT = ARCH_PERFMON_EVENTSEL_EVENT,
>> .MAX_NR_GP_COUNTERS = KVM_INTEL_PMC_MAX_GENERIC,
>> .MIN_NR_GP_COUNTERS = 1,
