[PATCH v2 8/9] KVM: return if kvm_vcpu_wake_up() did wake up the VCPU

Radim Krčmář
2017-04-26T20:33:29Z

No need to kick a VCPU that we have just woken up.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
include/linux/kvm_host.h | 2 +-
virt/kvm/kvm_main.c | 12 ++++++++----
2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 955debd82cf2..38cfe372918c 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -698,7 +698,7 @@ void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn);
void kvm_vcpu_block(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu);
-void kvm_vcpu_wake_up(struct kvm_vcpu *vcpu);
+bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu);
void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
int kvm_vcpu_yield_to(struct kvm_vcpu *target);
void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 1efb07643035..632f7b3e198c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -183,8 +183,8 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
kvm_make_request(req, vcpu);
cpu = vcpu->cpu;

- if (!(req & KVM_REQUEST_NO_WAKEUP))
- kvm_vcpu_wake_up(vcpu);
+ if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu))
+ continue;

if (cpus != NULL && cpu != -1 && cpu != me &&
kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
@@ -2195,7 +2195,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_vcpu_block);

-void kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
+bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
{
struct swait_queue_head *wqp;

@@ -2203,8 +2203,10 @@ void kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
if (swait_active(wqp)) {
swake_up(wqp);
++vcpu->stat.halt_wakeup;
+ return true;
}

+ return false;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up);

@@ -2216,7 +2218,9 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
int me;
int cpu = vcpu->cpu;

- kvm_vcpu_wake_up(vcpu);
+ if (kvm_vcpu_wake_up(vcpu))
+ return;
+
me = get_cpu();
if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
if (kvm_arch_vcpu_should_kick(vcpu))
--
2.12.2