Commit 6ed1298e authored by Like Xu's avatar Like Xu Committed by Paolo Bonzini
Browse files

KVM: x86/pmu: Reuse pmc_perf_hw_id() and drop find_fixed_event() 



Since we set the same semantic event value for the fixed counter in
pmc->eventsel, returning the perf_hw_id for the fixed counter via
find_fixed_event() can be painlessly replaced by pmc_perf_hw_id()
with the help of pmc_is_fixed() check.

Signed-off-by: default avatarLike Xu <likexu@tencent.com>
Message-Id: <20211130074221.93635-4-likexu@tencent.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 7c174f30

arch/x86/kvm/pmu.c

+1 −1
Original line number Diff line number Diff line
@@ -262,7 +262,7 @@ void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx) 


	pmc->current_config = (u64)ctrl;

	pmc_reprogram_counter(pmc, PERF_TYPE_HARDWARE,

			      kvm_x86_ops.pmu_ops->find_fixed_event(idx),

			      kvm_x86_ops.pmu_ops->pmc_perf_hw_id(pmc),

			      !(en_field & 0x2), /* exclude user */

			      !(en_field & 0x1), /* exclude kernel */

			      pmi, false, false);

arch/x86/kvm/pmu.h

+0 −1
Original line number Diff line number Diff line
@@ -25,7 +25,6 @@ struct kvm_event_hw_type_mapping { 


struct kvm_pmu_ops {

	unsigned int (*pmc_perf_hw_id)(struct kvm_pmc *pmc);

	unsigned (*find_fixed_event)(int idx);

	bool (*pmc_is_enabled)(struct kvm_pmc *pmc);

	struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);

	struct kvm_pmc *(*rdpmc_ecx_to_pmc)(struct kvm_vcpu *vcpu,

arch/x86/kvm/svm/pmu.c

+4 −7
Original line number Diff line number Diff line
@@ -144,6 +144,10 @@ static unsigned int amd_pmc_perf_hw_id(struct kvm_pmc *pmc) 
	u8 unit_mask = (pmc->eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;

	int i;



	/* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */

	if (WARN_ON(pmc_is_fixed(pmc)))

		return PERF_COUNT_HW_MAX;



	for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++)

		if (amd_event_mapping[i].eventsel == event_select

		    && amd_event_mapping[i].unit_mask == unit_mask)
@@ -155,12 +159,6 @@ static unsigned int amd_pmc_perf_hw_id(struct kvm_pmc *pmc) 
	return amd_event_mapping[i].event_type;

}



/* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */

static unsigned amd_find_fixed_event(int idx)

{

	return PERF_COUNT_HW_MAX;

}



/* check if a PMC is enabled by comparing it against global_ctrl bits. Because

 * AMD CPU doesn't have global_ctrl MSR, all PMCs are enabled (return TRUE).

 */
@@ -324,7 +322,6 @@ static void amd_pmu_reset(struct kvm_vcpu *vcpu) 


struct kvm_pmu_ops amd_pmu_ops = {

	.pmc_perf_hw_id = amd_pmc_perf_hw_id,

	.find_fixed_event = amd_find_fixed_event,

	.pmc_is_enabled = amd_pmc_is_enabled,

	.pmc_idx_to_pmc = amd_pmc_idx_to_pmc,

	.rdpmc_ecx_to_pmc = amd_rdpmc_ecx_to_pmc,

arch/x86/kvm/vmx/pmu_intel.c

+3 −16
Original line number Diff line number Diff line
@@ -76,9 +76,9 @@ static unsigned int intel_pmc_perf_hw_id(struct kvm_pmc *pmc) 
	int i;



	for (i = 0; i < ARRAY_SIZE(intel_arch_events); i++)

		if (intel_arch_events[i].eventsel == event_select

		    && intel_arch_events[i].unit_mask == unit_mask

		    && (pmu->available_event_types & (1 << i)))

		if (intel_arch_events[i].eventsel == event_select &&

		    intel_arch_events[i].unit_mask == unit_mask &&

		    (pmc_is_fixed(pmc) || pmu->available_event_types & (1 << i)))

			break;



	if (i == ARRAY_SIZE(intel_arch_events))
@@ -87,18 +87,6 @@ static unsigned int intel_pmc_perf_hw_id(struct kvm_pmc *pmc) 
	return intel_arch_events[i].event_type;

}



static unsigned intel_find_fixed_event(int idx)

{

	u32 event;

	size_t size = ARRAY_SIZE(fixed_pmc_events);



	if (WARN_ON_ONCE(idx >= size))

		return PERF_COUNT_HW_MAX;



	event = fixed_pmc_events[array_index_nospec(idx, size)];

	return intel_arch_events[event].event_type;

}



/* check if a PMC is enabled by comparing it with globl_ctrl bits. */

static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)

{
@@ -722,7 +710,6 @@ static void intel_pmu_cleanup(struct kvm_vcpu *vcpu) 


struct kvm_pmu_ops intel_pmu_ops = {

	.pmc_perf_hw_id = intel_pmc_perf_hw_id,

	.find_fixed_event = intel_find_fixed_event,

	.pmc_is_enabled = intel_pmc_is_enabled,

	.pmc_idx_to_pmc = intel_pmc_idx_to_pmc,

	.rdpmc_ecx_to_pmc = intel_rdpmc_ecx_to_pmc,