diff options
| author | Zhai, Edwin <edwin.zhai@intel.com> | 2009-10-09 18:03:20 +0800 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-12-03 09:32:17 +0200 |
| commit | d255f4f2bac81eb798fcf76938147f1f6c756ae2 (patch) | |
| tree | e00a5320033207436813afa109ef9404997fe773 | |
| parent | d36f19e9ecd22dc035ef4cc6361b564be650f8e7 (diff) | |
| download | lwn-d255f4f2bac81eb798fcf76938147f1f6c756ae2.tar.gz lwn-d255f4f2bac81eb798fcf76938147f1f6c756ae2.zip | |
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>
| -rw-r--r-- | include/linux/kvm_host.h | 1 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 15 |
2 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b985a29d8175..bd5a616d9373 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -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); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 70c8cbea0a99..cac69c4415df 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -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; |