Re: [PATCH v2 38/54] KVM: x86/pmu: Call perf_guest_enter() at PMU context switch

Mi, Dapeng
2024-05-08T04:22:07Z

On 5/7/2024 5:39 PM, Peter Zijlstra wrote:
> On Mon, May 06, 2024 at 05:30:03AM +0000, Mingwei Zhang wrote:
>> From: Xiong Zhang <xiong.y.zhang@linux.intel.com>
>>
>> perf subsystem should stop and restart all the perf events at the host
>> level when entering and leaving passthrough PMU respectively. So invoke
>> the perf API at PMU context switch functions.
>>
>> Signed-off-by: Xiong Zhang <xiong.y.zhang@linux.intel.com>
>> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
>> ---
>> arch/x86/events/core.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
>> index f5a043410614..6fe467bca809 100644
>> --- a/arch/x86/events/core.c
>> +++ b/arch/x86/events/core.c
>> @@ -705,6 +705,8 @@ void x86_perf_guest_enter(u32 guest_lvtpc)
>> {
>> lockdep_assert_irqs_disabled();
>>
>> + perf_guest_enter();
>> +
>> apic_write(APIC_LVTPC, APIC_DM_FIXED | KVM_GUEST_PMI_VECTOR |
>> (guest_lvtpc & APIC_LVT_MASKED));
>> }
>> @@ -715,6 +717,8 @@ void x86_perf_guest_exit(void)
>> lockdep_assert_irqs_disabled();
>>
>> apic_write(APIC_LVTPC, APIC_DM_NMI);
>> +
>> + perf_guest_exit();
>> }
>> EXPORT_SYMBOL_GPL(x86_perf_guest_exit);
> *sigh*.. why does this patch exist? Please merge with the one that
> introduces these functions.
>
> This is making review really hard.
Sure. we would adjust the patches sequence. Thanks.