KVM: X86: implement the logic for spinlock optimization
get_cpl requires vcpu_load, so we must cache the result (whether the
vcpu was preempted when its cpl=0) in kvm_vcpu_arch.
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6125e17..69b72c9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2873,6 +2873,10 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
int idx;
+
+ if (vcpu->preempted)
+ vcpu->arch.preempted_in_kernel = !kvm_x86_ops->get_cpl(vcpu);
+
/*
* Disable page faults because we're in atomic context here.
* kvm_write_guest_offset_cached() would call might_fault()
@@ -7985,6 +7989,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
kvm_pmu_init(vcpu);
vcpu->arch.pending_external_vector = -1;
+ vcpu->arch.preempted_in_kernel = false;
kvm_hv_vcpu_init(vcpu);
@@ -8434,7 +8439,7 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
{
- return false;
+ return vcpu->arch.preempted_in_kernel;
}
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)