KVM: use jump label to optimize checking for in kernel local apic presence
Usually all vcpus have local apic pointer initialized, so the check may
be completely skipped.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 7f77e96..650379b 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -152,6 +152,13 @@
return apic_sw_enabled(apic) && apic_hw_enabled(apic);
}
+static inline bool vcpu_has_lapic(struct kvm_vcpu *vcpu)
+{
+ if (static_key_false(&kvm_no_apic_vcpu))
+ return vcpu->arch.apic;
+ return true;
+}
+
#define LVT_MASK \
(APIC_LVT_MASKED | APIC_SEND_PENDING | APIC_VECTOR_MASK)
@@ -204,7 +211,7 @@
struct kvm_cpuid_entry2 *feat;
u32 v = APIC_VERSION;
- if (!irqchip_in_kernel(vcpu->kvm))
+ if (!vcpu_has_lapic(vcpu))
return;
feat = kvm_find_cpuid_entry(apic->vcpu, 0x1, 0);
@@ -305,7 +312,6 @@
int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu)
{
- struct kvm_lapic *apic = vcpu->arch.apic;
int highest_irr;
/* This may race with setting of irr in __apic_accept_irq() and
@@ -313,9 +319,9 @@
* will cause vmexit immediately and the value will be recalculated
* on the next vmentry.
*/
- if (!apic)
+ if (!vcpu_has_lapic(vcpu))
return 0;
- highest_irr = apic_find_highest_irr(apic);
+ highest_irr = apic_find_highest_irr(vcpu->arch.apic);
return highest_irr;
}
@@ -1061,9 +1067,7 @@
void kvm_lapic_set_eoi(struct kvm_vcpu *vcpu)
{
- struct kvm_lapic *apic = vcpu->arch.apic;
-
- if (apic)
+ if (vcpu_has_lapic(vcpu))
apic_reg_write(vcpu->arch.apic, APIC_EOI, 0);
}
EXPORT_SYMBOL_GPL(kvm_lapic_set_eoi);
@@ -1098,10 +1102,9 @@
u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu)
{
struct kvm_lapic *apic = vcpu->arch.apic;
- if (!apic)
- return 0;
- if (apic_lvtt_oneshot(apic) || apic_lvtt_period(apic))
+ if (!vcpu_has_lapic(vcpu) || apic_lvtt_oneshot(apic) ||
+ apic_lvtt_period(apic))
return 0;
return apic->lapic_timer.tscdeadline;
@@ -1110,10 +1113,9 @@
void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data)
{
struct kvm_lapic *apic = vcpu->arch.apic;
- if (!apic)
- return;
- if (apic_lvtt_oneshot(apic) || apic_lvtt_period(apic))
+ if (!vcpu_has_lapic(vcpu) || apic_lvtt_oneshot(apic) ||
+ apic_lvtt_period(apic))
return;
hrtimer_cancel(&apic->lapic_timer.timer);
@@ -1125,20 +1127,21 @@
{
struct kvm_lapic *apic = vcpu->arch.apic;
- if (!apic)
+ if (!vcpu_has_lapic(vcpu))
return;
+
apic_set_tpr(apic, ((cr8 & 0x0f) << 4)
| (apic_get_reg(apic, APIC_TASKPRI) & 4));
}
u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)
{
- struct kvm_lapic *apic = vcpu->arch.apic;
u64 tpr;
- if (!apic)
+ if (!vcpu_has_lapic(vcpu))
return 0;
- tpr = (u64) apic_get_reg(apic, APIC_TASKPRI);
+
+ tpr = (u64) apic_get_reg(vcpu->arch.apic, APIC_TASKPRI);
return (tpr & 0xf0) >> 4;
}
@@ -1237,7 +1240,7 @@
bool kvm_apic_present(struct kvm_vcpu *vcpu)
{
- return vcpu->arch.apic && apic_hw_enabled(vcpu->arch.apic);
+ return vcpu_has_lapic(vcpu) && apic_hw_enabled(vcpu->arch.apic);
}
int kvm_lapic_enabled(struct kvm_vcpu *vcpu)
@@ -1258,10 +1261,11 @@
int apic_has_pending_timer(struct kvm_vcpu *vcpu)
{
- struct kvm_lapic *lapic = vcpu->arch.apic;
+ struct kvm_lapic *apic = vcpu->arch.apic;
- if (lapic && apic_enabled(lapic) && apic_lvt_enabled(lapic, APIC_LVTT))
- return atomic_read(&lapic->lapic_timer.pending);
+ if (vcpu_has_lapic(vcpu) && apic_enabled(apic) &&
+ apic_lvt_enabled(apic, APIC_LVTT))
+ return atomic_read(&apic->lapic_timer.pending);
return 0;
}
@@ -1371,7 +1375,7 @@
struct kvm_lapic *apic = vcpu->arch.apic;
int highest_irr;
- if (!apic || !apic_enabled(apic))
+ if (!vcpu_has_lapic(vcpu) || !apic_enabled(apic))
return -1;
apic_update_ppr(apic);
@@ -1399,7 +1403,10 @@
{
struct kvm_lapic *apic = vcpu->arch.apic;
- if (apic && atomic_read(&apic->lapic_timer.pending) > 0) {
+ if (!vcpu_has_lapic(vcpu))
+ return;
+
+ if (atomic_read(&apic->lapic_timer.pending) > 0) {
if (kvm_apic_local_deliver(apic, APIC_LVTT))
atomic_dec(&apic->lapic_timer.pending);
}
@@ -1439,13 +1446,12 @@
void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
{
- struct kvm_lapic *apic = vcpu->arch.apic;
struct hrtimer *timer;
- if (!apic)
+ if (!vcpu_has_lapic(vcpu))
return;
- timer = &apic->lapic_timer.timer;
+ timer = &vcpu->arch.apic->lapic_timer.timer;
if (hrtimer_cancel(timer))
hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
}
@@ -1602,7 +1608,7 @@
{
struct kvm_lapic *apic = vcpu->arch.apic;
- if (!irqchip_in_kernel(vcpu->kvm))
+ if (!vcpu_has_lapic(vcpu))
return 1;
/* if this is ICR write vector before command */
@@ -1616,7 +1622,7 @@
struct kvm_lapic *apic = vcpu->arch.apic;
u32 low, high = 0;
- if (!irqchip_in_kernel(vcpu->kvm))
+ if (!vcpu_has_lapic(vcpu))
return 1;
if (apic_reg_read(apic, reg, 4, &low))