[PATCH 3/3] KVM: x86: optimize some accesses to LVTT and SPIV

From: Radim KrÄmÃÅ
Date: Thu Oct 30 2014 - 10:09:04 EST


We mirror a subset of these registers in separate variables.
Using them directly should be faster.

Signed-off-by: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 10 +++-------
arch/x86/kvm/lapic.h | 6 +++---
2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index d3a3a1c..67af5d2 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -239,21 +239,17 @@ static inline int apic_lvt_vector(struct kvm_lapic *apic, int lvt_type)

static inline int apic_lvtt_oneshot(struct kvm_lapic *apic)
{
- return ((kvm_apic_get_reg(apic, APIC_LVTT) &
- apic->lapic_timer.timer_mode_mask) == APIC_LVT_TIMER_ONESHOT);
+ return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_ONESHOT;
}

static inline int apic_lvtt_period(struct kvm_lapic *apic)
{
- return ((kvm_apic_get_reg(apic, APIC_LVTT) &
- apic->lapic_timer.timer_mode_mask) == APIC_LVT_TIMER_PERIODIC);
+ return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_PERIODIC;
}

static inline int apic_lvtt_tscdeadline(struct kvm_lapic *apic)
{
- return ((kvm_apic_get_reg(apic, APIC_LVTT) &
- apic->lapic_timer.timer_mode_mask) ==
- APIC_LVT_TIMER_TSCDEADLINE);
+ return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_TSCDEADLINE;
}

static inline int apic_lvt_nmi_mode(u32 lvt_val)
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 755a954..2c56885 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -121,11 +121,11 @@ static inline int kvm_apic_hw_enabled(struct kvm_lapic *apic)

extern struct static_key_deferred apic_sw_disabled;

-static inline int kvm_apic_sw_enabled(struct kvm_lapic *apic)
+static inline bool kvm_apic_sw_enabled(struct kvm_lapic *apic)
{
if (static_key_false(&apic_sw_disabled.key))
- return kvm_apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_APIC_ENABLED;
- return APIC_SPIV_APIC_ENABLED;
+ return apic->sw_enabled;
+ return true;
}

static inline bool kvm_apic_present(struct kvm_vcpu *vcpu)
--
2.1.0

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