[PATCH 2/2] KVM: x86/pmu: Manipulate FIXED_CTR_CTRL MSR with macros

From: Dapeng Mi
Date: Mon Apr 29 2024 - 20:46:31 EST


Magic numbers are used to manipulate the bit fields of
FIXED_CTR_CTRL MSR. This makes reading code become difficult, so use
pre-defined macros to replace these magic numbers.

Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/pmu.c | 10 +++++-----
arch/x86/kvm/pmu.h | 6 ++++--
arch/x86/kvm/vmx/pmu_intel.c | 12 +++++++++---
3 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index afbd67ca782c..0314a4fe8b2d 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -469,11 +469,11 @@ static int reprogram_counter(struct kvm_pmc *pmc)
if (pmc_is_fixed(pmc)) {
fixed_ctr_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl,
pmc->idx - KVM_FIXED_PMC_BASE_IDX);
- if (fixed_ctr_ctrl & 0x1)
+ if (fixed_ctr_ctrl & INTEL_FIXED_0_KERNEL)
eventsel |= ARCH_PERFMON_EVENTSEL_OS;
- if (fixed_ctr_ctrl & 0x2)
+ if (fixed_ctr_ctrl & INTEL_FIXED_0_USER)
eventsel |= ARCH_PERFMON_EVENTSEL_USR;
- if (fixed_ctr_ctrl & 0x8)
+ if (fixed_ctr_ctrl & INTEL_FIXED_0_ENABLE_PMI)
eventsel |= ARCH_PERFMON_EVENTSEL_INT;
new_config = (u64)fixed_ctr_ctrl;
}
@@ -846,8 +846,8 @@ static inline bool cpl_is_matched(struct kvm_pmc *pmc)
} else {
config = fixed_ctrl_field(pmc_to_pmu(pmc)->fixed_ctr_ctrl,
pmc->idx - KVM_FIXED_PMC_BASE_IDX);
- select_os = config & 0x1;
- select_user = config & 0x2;
+ select_os = config & INTEL_FIXED_0_KERNEL;
+ select_user = config & INTEL_FIXED_0_USER;
}

/*
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 2eab8ea610db..d54741fe4bdd 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -14,7 +14,8 @@
MSR_IA32_MISC_ENABLE_BTS_UNAVAIL)

/* retrieve the 4 bits for EN and PMI out of IA32_FIXED_CTR_CTRL */
-#define fixed_ctrl_field(ctrl_reg, idx) (((ctrl_reg) >> ((idx)*4)) & 0xf)
+#define fixed_ctrl_field(ctrl_reg, idx) \
+ (((ctrl_reg) >> ((idx) * INTEL_FIXED_BITS_STRIDE)) & INTEL_FIXED_BITS_MASK)

#define VMWARE_BACKDOOR_PMC_HOST_TSC 0x10000
#define VMWARE_BACKDOOR_PMC_REAL_TIME 0x10001
@@ -170,7 +171,8 @@ static inline bool pmc_speculative_in_use(struct kvm_pmc *pmc)

if (pmc_is_fixed(pmc))
return fixed_ctrl_field(pmu->fixed_ctr_ctrl,
- pmc->idx - KVM_FIXED_PMC_BASE_IDX) & 0x3;
+ pmc->idx - KVM_FIXED_PMC_BASE_IDX) &
+ (INTEL_FIXED_0_KERNEL | INTEL_FIXED_0_USER);

return pmc->eventsel & ARCH_PERFMON_EVENTSEL_ENABLE;
}
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index eaee9a08952e..846a4e7fd34a 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -501,8 +501,14 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
((u64)1 << edx.split.bit_width_fixed) - 1;
}

- for (i = 0; i < pmu->nr_arch_fixed_counters; i++)
- pmu->fixed_ctr_ctrl_rsvd &= ~(0xbull << (i * 4));
+ for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
+ pmu->fixed_ctr_ctrl_rsvd &=
+ ~intel_fixed_bits_by_idx(i,
+ INTEL_FIXED_0_KERNEL |
+ INTEL_FIXED_0_USER |
+ INTEL_FIXED_0_ENABLE_PMI);
+ }
+
counter_rsvd = ~(((1ull << pmu->nr_arch_gp_counters) - 1) |
(((1ull << pmu->nr_arch_fixed_counters) - 1) << KVM_FIXED_PMC_BASE_IDX));
pmu->global_ctrl_rsvd = counter_rsvd;
@@ -548,7 +554,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
pmu->reserved_bits &= ~ICL_EVENTSEL_ADAPTIVE;
for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
pmu->fixed_ctr_ctrl_rsvd &=
- ~(1ULL << (KVM_FIXED_PMC_BASE_IDX + i * 4));
+ ~intel_fixed_bits_by_idx(i, ICL_FIXED_0_ADAPTIVE);
}
pmu->pebs_data_cfg_rsvd = ~0xff00000full;
} else {
--
2.40.1