KVM: introduce kvm_vcpu_on_spin

Introduce kvm_vcpu_on_spin, to be used by VMX/SVM to yield processing
once the cpu detects pause-based looping.

Signed-off-by: "Zhai, Edwin" <edwin.zhai@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Zhai, Edwin 2009-10-09 18:03:20 +08:00 committed by Avi Kivity
parent d36f19e9ec
commit d255f4f2ba
2 changed files with 16 additions and 0 deletions

View file

@ -286,6 +286,7 @@ int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn);
void mark_page_dirty(struct kvm *kvm, gfn_t gfn);
void kvm_vcpu_block(struct kvm_vcpu *vcpu);
void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu);
void kvm_resched(struct kvm_vcpu *vcpu);
void kvm_load_guest_fpu(struct kvm_vcpu *vcpu);
void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);

View file

@ -1108,6 +1108,21 @@ void kvm_resched(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_resched);
void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu)
{
ktime_t expires;
DEFINE_WAIT(wait);
prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
/* Sleep for 100 us, and hope lock-holder got scheduled */
expires = ktime_add_ns(ktime_get(), 100000UL);
schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
finish_wait(&vcpu->wq, &wait);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct kvm_vcpu *vcpu = vma->vm_file->private_data;