KVM: x86: Clarify PMU related features bit manipulation

[sfrench/cifs-2.6.git] / arch / x86 / kvm / pmu.c

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 3dd6accb64ec130d28db81f501f95aa7726c4002..8e6b7d869d2f7f34432a1f1685606eab7945561a 100644 (file)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -15,6 +15,7 @@
 #include <linux/types.h>
 #include <linux/kvm_host.h>
 #include <linux/perf_event.h>
+#include <asm/perf_event.h>
 #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) |