KVM: Accelerated apic support
This adds a mechanism for exposing the virtual apic tpr to the guest, and a
protocol for letting the guest update the tpr without causing a vmexit if
conditions allow (e.g. there is no interrupt pending with a higher priority
than the new tpr).
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 50c3f3a..e7513bb 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -815,7 +815,8 @@
if (!apic)
return;
- apic_set_tpr(apic, ((cr8 & 0x0f) << 4));
+ apic_set_tpr(apic, ((cr8 & 0x0f) << 4)
+ | (apic_get_reg(apic, APIC_TASKPRI) & 4));
}
u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)
@@ -1104,3 +1105,51 @@
hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS);
}
EXPORT_SYMBOL_GPL(kvm_migrate_apic_timer);
+
+void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
+{
+ u32 data;
+ void *vapic;
+
+ if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)
+ return;
+
+ vapic = kmap_atomic(vcpu->arch.apic->vapic_page, KM_USER0);
+ data = *(u32 *)(vapic + offset_in_page(vcpu->arch.apic->vapic_addr));
+ kunmap_atomic(vapic, KM_USER0);
+
+ apic_set_tpr(vcpu->arch.apic, data & 0xff);
+}
+
+void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
+{
+ u32 data, tpr;
+ int max_irr, max_isr;
+ struct kvm_lapic *apic;
+ void *vapic;
+
+ if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)
+ return;
+
+ apic = vcpu->arch.apic;
+ tpr = apic_get_reg(apic, APIC_TASKPRI) & 0xff;
+ max_irr = apic_find_highest_irr(apic);
+ if (max_irr < 0)
+ max_irr = 0;
+ max_isr = apic_find_highest_isr(apic);
+ if (max_isr < 0)
+ max_isr = 0;
+ data = (tpr & 0xff) | ((max_isr & 0xf0) << 8) | (max_irr << 24);
+
+ vapic = kmap_atomic(vcpu->arch.apic->vapic_page, KM_USER0);
+ *(u32 *)(vapic + offset_in_page(vcpu->arch.apic->vapic_addr)) = data;
+ kunmap_atomic(vapic, KM_USER0);
+}
+
+void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
+{
+ if (!irqchip_in_kernel(vcpu->kvm))
+ return;
+
+ vcpu->arch.apic->vapic_addr = vapic_addr;
+}