[PATCH 2/5] kvm: add helper for testing ready async_pf's

[Roman Kagan <rkagan@virtuozzo.com>]

Add helper inline function to test if there are async_pf's ready on a
given vCPU.  There are already 3 callsites for it and I'm about to add
more.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
 include/linux/kvm_host.h | 7 +++++++
 arch/x86/kvm/x86.c       | 2 +-
 virt/kvm/async_pf.c      | 4 ++--
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 01c0b9c..e10516f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1207,4 +1207,11 @@ static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu)
 }
 #endif /* CONFIG_HAVE_KVM_INVALID_WAKEUPS */
 
+#ifdef CONFIG_KVM_ASYNC_PF
+static inline bool kvm_async_pf_has_ready(struct kvm_vcpu *vcpu)
+{
+	return !list_empty_careful(&vcpu->async_pf.done);
+}
+#endif
+
 #endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 14a46e9..638fc5f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8182,7 +8182,7 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
 
 static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
 {
-	if (!list_empty_careful(&vcpu->async_pf.done))
+	if (kvm_async_pf_has_ready(vcpu))
 		return true;
 
 	if (kvm_apic_has_events(vcpu))
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index efeceb0a..9cced14 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -159,7 +159,7 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
 {
 	struct kvm_async_pf *work;
 
-	while (!list_empty_careful(&vcpu->async_pf.done) &&
+	while (kvm_async_pf_has_ready(vcpu) &&
 	      kvm_arch_can_inject_async_page_present(vcpu)) {
 		spin_lock(&vcpu->async_pf.lock);
 		work = list_first_entry(&vcpu->async_pf.done, typeof(*work),
@@ -227,7 +227,7 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
 {
 	struct kvm_async_pf *work;
 
-	if (!list_empty_careful(&vcpu->async_pf.done))
+	if (kvm_async_pf_has_ready(vcpu))
 		return 0;
 
 	work = kmem_cache_zalloc(async_pf_cache, GFP_ATOMIC);
-- 
2.9.3