[PATCH v3 2/5] KVM: x86/pmu: Add the base address parameter for get_fixed_pmc()

From: Like Xu
Date: Wed May 12 2021 - 04:46:19 EST


From: Luwei Kang <luwei.kang@xxxxxxxxx>

Introduce a new base MSR address pass-in parameter for get_fixed_pmc()
so that the caller can define its base for fixed counters (such as
MSR_RELOAD_FIXED_CTRx that can be used in the PBES-via-PT feature).

Refactor the code using the current value MSR_CORE_PERF_FIXED_CTR0.

Signed-off-by: Luwei Kang <luwei.kang@xxxxxxxxx>
---
The checkpatch.pl yell "ERROR: do not use assignment in if condition",
should I fix the orignal coding style ?

arch/x86/kvm/pmu.h | 5 ++---
arch/x86/kvm/vmx/pmu_intel.c | 17 +++++++++++------
2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 832cf56e6924..6720881b8370 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -126,10 +126,9 @@ static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr,
}

/* returns fixed PMC with the specified MSR */
-static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
+static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu,
+ u32 msr, u32 base)
{
- int base = MSR_CORE_PERF_FIXED_CTR0;
-
if (msr >= base && msr < base + pmu->nr_arch_fixed_counters) {
u32 index = array_index_nospec(msr - base,
pmu->nr_arch_fixed_counters);
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index a706d3597720..c10cb3008bf1 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -44,7 +44,8 @@ static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
u8 old_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, i);
struct kvm_pmc *pmc;

- pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
+ pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i,
+ MSR_CORE_PERF_FIXED_CTR0);

if (old_ctrl == new_ctrl)
continue;
@@ -114,7 +115,8 @@ static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
else {
u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED;

- return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0);
+ return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0,
+ MSR_CORE_PERF_FIXED_CTR0);
}
}

@@ -222,7 +224,8 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
default:
ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||
get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) ||
- get_fixed_pmc(pmu, msr) || get_fw_gp_pmc(pmu, msr) ||
+ get_fixed_pmc(pmu, msr, MSR_CORE_PERF_FIXED_CTR0) ||
+ get_fw_gp_pmc(pmu, msr) ||
intel_pmu_is_valid_lbr_msr(vcpu, msr);
break;
}
@@ -235,7 +238,7 @@ static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr)
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;

- pmc = get_fixed_pmc(pmu, msr);
+ pmc = get_fixed_pmc(pmu, msr, MSR_CORE_PERF_FIXED_CTR0);
pmc = pmc ? pmc : get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0);
pmc = pmc ? pmc : get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0);

@@ -382,7 +385,8 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data =
val & pmu->counter_bitmask[KVM_PMC_GP];
return 0;
- } else if ((pmc = get_fixed_pmc(pmu, msr))) {
+ } else if ((pmc = get_fixed_pmc(pmu, msr,
+ MSR_CORE_PERF_FIXED_CTR0))) {
u64 val = pmc_read_counter(pmc);
msr_info->data =
val & pmu->counter_bitmask[KVM_PMC_FIXED];
@@ -470,7 +474,8 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
perf_event_period(pmc->perf_event,
get_sample_period(pmc, data));
return 0;
- } else if ((pmc = get_fixed_pmc(pmu, msr))) {
+ } else if ((pmc = get_fixed_pmc(pmu, msr,
+ MSR_CORE_PERF_FIXED_CTR0))) {
pmc->counter += data - pmc_read_counter(pmc);
if (pmc->perf_event)
perf_event_period(pmc->perf_event,
--
2.31.1