From d27aa7f15c3b1105c8cd8c2d190ab354f877cac5 Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Wed, 20 Aug 2014 13:25:52 +0300 Subject: [PATCH] KVM: x86: Clarify PMU related features bit manipulation kvm_pmu_cpuid_update makes a lot of bit manuiplation operations, when in fact there are already unions that can be used instead. Changing the bit manipulation to the union for clarity. This patch does not change the functionality. Signed-off-by: Nadav Amit Signed-off-by: Paolo Bonzini --- arch/x86/kvm/pmu.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 3dd6accb64ec..8e6b7d869d2f 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "x86.h" #include "cpuid.h" #include "lapic.h" @@ -463,7 +464,8 @@ void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu) { struct kvm_pmu *pmu = &vcpu->arch.pmu; struct kvm_cpuid_entry2 *entry; - unsigned bitmap_len; + union cpuid10_eax eax; + union cpuid10_edx edx; pmu->nr_arch_gp_counters = 0; pmu->nr_arch_fixed_counters = 0; @@ -475,25 +477,27 @@ void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu) entry = kvm_find_cpuid_entry(vcpu, 0xa, 0); if (!entry) return; + eax.full = entry->eax; + edx.full = entry->edx; - pmu->version = entry->eax & 0xff; + pmu->version = eax.split.version_id; if (!pmu->version) return; - pmu->nr_arch_gp_counters = min((int)(entry->eax >> 8) & 0xff, - INTEL_PMC_MAX_GENERIC); - pmu->counter_bitmask[KVM_PMC_GP] = - ((u64)1 << ((entry->eax >> 16) & 0xff)) - 1; - bitmap_len = (entry->eax >> 24) & 0xff; - pmu->available_event_types = ~entry->ebx & ((1ull << bitmap_len) - 1); + pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters, + INTEL_PMC_MAX_GENERIC); + pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1; + pmu->available_event_types = ~entry->ebx & + ((1ull << eax.split.mask_length) - 1); if (pmu->version == 1) { pmu->nr_arch_fixed_counters = 0; } else { - pmu->nr_arch_fixed_counters = min((int)(entry->edx & 0x1f), + pmu->nr_arch_fixed_counters = + min_t(int, edx.split.num_counters_fixed, INTEL_PMC_MAX_FIXED); pmu->counter_bitmask[KVM_PMC_FIXED] = - ((u64)1 << ((entry->edx >> 5) & 0xff)) - 1; + ((u64)1 << edx.split.bit_width_fixed) - 1; } pmu->global_ctrl = ((1 << pmu->nr_arch_gp_counters) - 1) | -- 2.39.5