diff options
| author | Nadav Amit <namit@cs.technion.ac.il> | 2014-08-20 10:25:52 (GMT) |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-08-20 11:01:25 (GMT) |
| commit | d27aa7f15c3b1105c8cd8c2d190ab354f877cac5 (patch) | |
| tree | 8dc7288ebafc088d36fa192950893ce8126d18b6 /arch | |
| parent | a32e84594ddf018cc618a8781298804c3e6131ce (diff) | |
| download | linux-d27aa7f15c3b1105c8cd8c2d190ab354f877cac5.tar.xz | |
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 <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/pmu.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 3dd6acc..8e6b7d8 100644 --- 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) | |