[Patch v3] KVM: x86/pmu: Manipulate FIXED_CTR_CTRL MSR with macros

From: Dapeng Mi
Date: Wed Aug 23 2023 - 21:59:30 EST


Magic numbers are used to manipulate the bit fields of
FIXED_CTR_CTRL MSR. This is not read-friendly and use macros to replace
these magic numbers to increase the readability.

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 | 11 ++++++++---
3 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index edb89b51b383..fb4ef2da3e32 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -420,11 +420,11 @@ static void reprogram_counter(struct kvm_pmc *pmc)
if (pmc_is_fixed(pmc)) {
fixed_ctr_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl,
pmc->idx - INTEL_PMC_IDX_FIXED);
- 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;
}
@@ -749,8 +749,8 @@ static inline bool cpl_is_matched(struct kvm_pmc *pmc)
} else {
config = fixed_ctrl_field(pmc_to_pmu(pmc)->fixed_ctr_ctrl,
pmc->idx - INTEL_PMC_IDX_FIXED);
- select_os = config & 0x1;
- select_user = config & 0x2;
+ select_os = config & INTEL_FIXED_0_KERNEL;
+ select_user = config & INTEL_FIXED_0_USER;
}

return (static_call(kvm_x86_get_cpl)(pmc->vcpu) == 0) ? select_os : select_user;
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 7d9ba301c090..ffda2ecc3a22 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -12,7 +12,8 @@
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
@@ -165,7 +166,8 @@ 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 - INTEL_PMC_IDX_FIXED) & 0x3;
+ pmc->idx - INTEL_PMC_IDX_FIXED) &
+ (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 f2efa0bf7ae8..b0ac55891cb7 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -548,8 +548,13 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
setup_fixed_pmc_eventsel(pmu);
}

- for (i = 0; i < pmu->nr_arch_fixed_counters; i++)
- pmu->fixed_ctr_ctrl_mask &= ~(0xbull << (i * 4));
+ for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
+ pmu->fixed_ctr_ctrl_mask &=
+ ~intel_fixed_bits_by_idx(i,
+ INTEL_FIXED_0_KERNEL |
+ INTEL_FIXED_0_USER |
+ INTEL_FIXED_0_ENABLE_PMI);
+ }
counter_mask = ~(((1ull << pmu->nr_arch_gp_counters) - 1) |
(((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED));
pmu->global_ctrl_mask = counter_mask;
@@ -595,7 +600,7 @@ 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_mask &=
- ~(1ULL << (INTEL_PMC_IDX_FIXED + i * 4));
+ ~intel_fixed_bits_by_idx(i, ICL_FIXED_0_ADAPTIVE);
}
pmu->pebs_data_cfg_mask = ~0xff00000full;
} else {

base-commit: fff2e47e6c3b8050ca26656693caa857e3a8b740
--
2.34.1