KVM: Introduce bitmask for apic attention reasons
The patch introduces a bitmap that will hold reasons apic should be
checked during vmexit. This is in a preparation for vp eoi patch
that will add one more check on vmexit. With the bitmap we can do
if(apic_attention) to check everything simultaneously which will
add zero overhead on the fast path.
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 992b4ea..93c1574 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1088,6 +1088,7 @@
apic_update_ppr(apic);
vcpu->arch.apic_arb_prio = 0;
+ vcpu->arch.apic_attention = 0;
apic_debug(KERN_INFO "%s: vcpu=%p, id=%d, base_msr="
"0x%016" PRIx64 ", base_address=0x%0lx.\n", __func__,
@@ -1287,7 +1288,7 @@
u32 data;
void *vapic;
- if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)
+ if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
return;
vapic = kmap_atomic(vcpu->arch.apic->vapic_page);
@@ -1304,7 +1305,7 @@
struct kvm_lapic *apic;
void *vapic;
- if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)
+ if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
return;
apic = vcpu->arch.apic;
@@ -1324,10 +1325,11 @@
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;
+ if (vapic_addr)
+ __set_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention);
+ else
+ __clear_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention);
}
int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)