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From: Like Xu <like.xu.linux@gmail.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, kvm@vger.kernel.org
Subject: Re: [kvm-unit-tests PATCH v3 10/13] x86/pmu: Update testcases to cover Intel Arch PMU Version 1
Date: Tue, 18 Oct 2022 17:32:59 +0800	[thread overview]
Message-ID: <4b9d7939-ebd5-385d-d0cc-e95955e0238f@gmail.com> (raw)
In-Reply-To: <Yz4GtqyPIMCMsUEl@google.com>

All applied except pmu_clear_global_status_safe(). Thanks.

On 6/10/2022 6:35 am, Sean Christopherson wrote:
> On Fri, Aug 19, 2022, Like Xu wrote:
>> From: Like Xu <likexu@tencent.com>
>>
>> For most unit tests, the basic framework and use cases which test
>> any PMU counter do not require any changes, except for two things:
>>
>> - No access to registers introduced only in PMU version 2 and above;
>> - Expanded tolerance for testing counter overflows
>>    due to the loss of uniform control of the gloabl_ctrl register
>>
>> Adding some pmu_version() return value checks can seamlessly support
>> Intel Arch PMU Version 1, while opening the door for AMD PMUs tests.
> 
> Phrase this as a command so that it's crystal clear that this is what the patch
> does, as opposed to what the patch _can_ do.
> 
>> Signed-off-by: Like Xu <likexu@tencent.com>
>> ---
>>   x86/pmu.c | 64 +++++++++++++++++++++++++++++++++++++------------------
>>   1 file changed, 43 insertions(+), 21 deletions(-)
>>
>> diff --git a/x86/pmu.c b/x86/pmu.c
>> index 25fafbe..826472c 100644
>> --- a/x86/pmu.c
>> +++ b/x86/pmu.c
>> @@ -125,14 +125,19 @@ static struct pmu_event* get_counter_event(pmu_counter_t *cnt)
>>   
>>   static void global_enable(pmu_counter_t *cnt)
>>   {
>> -	cnt->idx = event_to_global_idx(cnt);
>> +	if (pmu_version() < 2)
> 
> Helper please.
> 
>> +		return;
>>   
>> +	cnt->idx = event_to_global_idx(cnt);
>>   	wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, rdmsr(MSR_CORE_PERF_GLOBAL_CTRL) |
>>   			(1ull << cnt->idx));
>>   }
>>   
>>   static void global_disable(pmu_counter_t *cnt)
>>   {
>> +	if (pmu_version() < 2)
>> +		return;
>> +
>>   	wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, rdmsr(MSR_CORE_PERF_GLOBAL_CTRL) &
>>   			~(1ull << cnt->idx));
>>   }
>> @@ -301,7 +306,10 @@ static void check_counter_overflow(void)
>>   	count = cnt.count;
>>   
>>   	/* clear status before test */
>> -	wrmsr(MSR_CORE_PERF_GLOBAL_OVF_CTRL, rdmsr(MSR_CORE_PERF_GLOBAL_STATUS));
>> +	if (pmu_version() > 1) {
> 
> Should be a helper to use from an earlier patch.
> 
> Hmm, looking forward, maybe have an upper level helper?  E.g.
> 
>    void pmu_clear_global_status_safe(void)
>    {
> 	if (!exists)
> 		return
> 
> 	wrmsr(...);
>    }
> 
> Ignore this suggestion if these checks go away in the future.
> 
>> +		wrmsr(MSR_CORE_PERF_GLOBAL_OVF_CTRL,
>> +		      rdmsr(MSR_CORE_PERF_GLOBAL_STATUS));
>> +	}
>>   
>>   	report_prefix_push("overflow");
>>   
>> @@ -327,13 +335,21 @@ static void check_counter_overflow(void)
>>   			cnt.config &= ~EVNTSEL_INT;
>>   		idx = event_to_global_idx(&cnt);
>>   		__measure(&cnt, cnt.count);
>> -		report(cnt.count == 1, "cntr-%d", i);
>> +
>> +		report(check_irq() == (i % 2), "irq-%d", i);
>> +		if (pmu_version() > 1)
> 
> Helper.
> 
>> +			report(cnt.count == 1, "cntr-%d", i);
>> +		else
>> +			report(cnt.count < 4, "cntr-%d", i);
>> +
>> +		if (pmu_version() < 2)
> 
> Helper.
> 
>> +			continue;
>> +
>>   		status = rdmsr(MSR_CORE_PERF_GLOBAL_STATUS);
>>   		report(status & (1ull << idx), "status-%d", i);
>>   		wrmsr(MSR_CORE_PERF_GLOBAL_OVF_CTRL, status);
>>   		status = rdmsr(MSR_CORE_PERF_GLOBAL_STATUS);
>>   		report(!(status & (1ull << idx)), "status clear-%d", i);
>> -		report(check_irq() == (i % 2), "irq-%d", i);
>>   	}
>>   
>>   	report_prefix_pop();
>> @@ -440,8 +456,10 @@ static void check_running_counter_wrmsr(void)
>>   	report(evt.count < gp_events[1].min, "cntr");
>>   
>>   	/* clear status before overflow test */
>> -	wrmsr(MSR_CORE_PERF_GLOBAL_OVF_CTRL,
>> -	      rdmsr(MSR_CORE_PERF_GLOBAL_STATUS));
>> +	if (pmu_version() > 1) {
> 
> Helper.  Curly braces aren't necessary.
> 
>> +		wrmsr(MSR_CORE_PERF_GLOBAL_OVF_CTRL,
>> +			rdmsr(MSR_CORE_PERF_GLOBAL_STATUS));
>> +	}
>>   
>>   	start_event(&evt);
>>   
>> @@ -453,8 +471,11 @@ static void check_running_counter_wrmsr(void)
>>   
>>   	loop();
>>   	stop_event(&evt);
>> -	status = rdmsr(MSR_CORE_PERF_GLOBAL_STATUS);
>> -	report(status & 1, "status");
>> +
>> +	if (pmu_version() > 1) {
> 
> Helper.
> 
>> +		status = rdmsr(MSR_CORE_PERF_GLOBAL_STATUS);
>> +		report(status & 1, "status");
> 
> Can you opportunistically provide a better message than "status"?
> 
>> +	}
>>   
>>   	report_prefix_pop();
>>   }
>> @@ -474,8 +495,10 @@ static void check_emulated_instr(void)
>>   	};
>>   	report_prefix_push("emulated instruction");
>>   
>> -	wrmsr(MSR_CORE_PERF_GLOBAL_OVF_CTRL,
>> -	      rdmsr(MSR_CORE_PERF_GLOBAL_STATUS));
>> +	if (pmu_version() > 1) {
> 
> Helper, no curly braces.  Ah, IIRC, kernel perf prefers curly braces if the code
> spans multiple lines.  KVM and KUT does not.

OK.

> 
>> +		wrmsr(MSR_CORE_PERF_GLOBAL_OVF_CTRL,
>> +			rdmsr(MSR_CORE_PERF_GLOBAL_STATUS));
>> +	}
>>   
>>   	start_event(&brnch_cnt);
>>   	start_event(&instr_cnt);
>> @@ -509,7 +532,8 @@ static void check_emulated_instr(void)
>>   		:
>>   		: "eax", "ebx", "ecx", "edx");
>>   
>> -	wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
>> +	if (pmu_version() > 1)
> 
> Helper.
> 
>> +		wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
>>   
>>   	stop_event(&brnch_cnt);
>>   	stop_event(&instr_cnt);
>> @@ -520,10 +544,13 @@ static void check_emulated_instr(void)
>>   	       "instruction count");
>>   	report(brnch_cnt.count - brnch_start >= EXPECTED_BRNCH,
>>   	       "branch count");
>> -	// Additionally check that those counters overflowed properly.
>> -	status = rdmsr(MSR_CORE_PERF_GLOBAL_STATUS);
>> -	report(status & 1, "instruction counter overflow");
>> -	report(status & 2, "branch counter overflow");
>> +
>> +	if (pmu_version() > 1) {
> 
> Helper?  E.g. if this is a "has architectural PMU".

Nit, "intel arch pmu" means "version > 0".

> 
>> +		// Additionally check that those counters overflowed properly.
>> +		status = rdmsr(MSR_CORE_PERF_GLOBAL_STATUS);
>> +		report(status & 1, "instruction counter overflow");
>> +		report(status & 2, "branch counter overflow");
>> +	}
>>   
>>   	report_prefix_pop();
>>   }
>> @@ -647,12 +674,7 @@ int main(int ac, char **av)
>>   	buf = malloc(N*64);
>>   
>>   	if (!pmu_version()) {
>> -		report_skip("No pmu is detected!");
>> -		return report_summary();
>> -	}
>> -
>> -	if (pmu_version() == 1) {
>> -		report_skip("PMU version 1 is not supported.");
>> +		report_skip("No Intel Arch PMU is detected!");
>>   		return report_summary();
>>   	}
>>   
>> -- 
>> 2.37.2
>>

  reply	other threads:[~2022-10-18  9:33 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-19 11:09 [kvm-unit-tests PATCH v3 00/13] x86/pmu: Test case optimization, fixes and additions Like Xu
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 01/13] x86/pmu: Introduce __start_event() to drop all of the manual zeroing Like Xu
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 02/13] x86/pmu: Introduce multiple_{one, many}() to improve readability Like Xu
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 03/13] x86/pmu: Reset the expected count of the fixed counter 0 when i386 Like Xu
2022-10-05 22:18   ` Sean Christopherson
2022-10-17  7:30     ` Like Xu
2022-10-21 19:16       ` Sean Christopherson
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 04/13] x86/pmu: Add tests for Intel Processor Event Based Sampling (PEBS) Like Xu
2022-10-05 22:21   ` Sean Christopherson
2022-10-05 22:22     ` Sean Christopherson
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 05/13] x86: create pmu group for quick pmu-scope testing Like Xu
2022-10-05 22:23   ` Sean Christopherson
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 06/13] x86/pmu: Test emulation instructions on full-width counters Like Xu
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 07/13] x86/pmu: Pop up FW prefix to avoid out-of-context propagation Like Xu
2022-10-05 22:25   ` Sean Christopherson
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 08/13] x86/pmu: Add PDCM check before accessing PERF_CAP register Like Xu
2022-10-05 22:28   ` Sean Christopherson
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 09/13] x86/pmu: Report SKIP when testing Intel LBR on AMD platforms Like Xu
2022-10-05 22:29   ` Sean Christopherson
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 10/13] x86/pmu: Update testcases to cover Intel Arch PMU Version 1 Like Xu
2022-09-06  7:15   ` Sandipan Das
2022-09-06 13:28     ` Like Xu
2022-09-06  8:16   ` Sandipan Das
2022-09-06 13:35     ` Like Xu
2022-09-08  8:23       ` Sandipan Das
2022-09-19  7:09         ` Like Xu
2022-10-21  7:32           ` Like Xu
2022-10-25  8:34             ` Sandipan Das
2022-10-05 22:35   ` Sean Christopherson
2022-10-18  9:32     ` Like Xu [this message]
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 11/13] x86/pmu: Refine message when testing PMU on AMD platforms Like Xu
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 12/13] x86/pmu: Add assignment framework for Intel-specific HW resources Like Xu
2022-09-06  7:19   ` Sandipan Das
2022-10-05 22:44   ` Sean Christopherson
2022-10-21  7:21     ` Like Xu
2022-10-21 18:22       ` Sean Christopherson
2022-08-19 11:09 ` [kvm-unit-tests PATCH v3 13/13] x86/pmu: Update testcases to cover AMD PMU Like Xu
2022-09-06  7:32   ` Sandipan Das
2022-10-05 22:48   ` Sean Christopherson

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