[PATCH v4 08/11] KVM: Move nVMX's lockdep logic for vcpu->mutex to a common helper

[Sean Christopherson <seanjc@google.com>]

Extract nVMX's lockdep assertion that a vCPU is locked or otherwise
unreachable into a common helper, as KVM x86 is about to gain another user,
but there is nothing x86-specific about the logic, i.e. the assertion may
be useful for other architectures.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/vmx/nested.h | 6 ++----
 include/linux/kvm_host.h  | 6 ++++++
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index 6d6cd5904ddf..c6de848bd9ce 100644
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -57,16 +57,14 @@ bool nested_vmx_check_io_bitmaps(struct kvm_vcpu *vcpu, unsigned int port,
 
 static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)
 {
-	lockdep_assert_once(lockdep_is_held(&vcpu->mutex) ||
-			    !refcount_read(&vcpu->kvm->users_count));
+	kvm_lockdep_assert_vcpu_is_locked_or_unreachable(vcpu);
 
 	return to_vmx(vcpu)->nested.cached_vmcs12;
 }
 
 static inline struct vmcs12 *get_shadow_vmcs12(struct kvm_vcpu *vcpu)
 {
-	lockdep_assert_once(lockdep_is_held(&vcpu->mutex) ||
-			    !refcount_read(&vcpu->kvm->users_count));
+	kvm_lockdep_assert_vcpu_is_locked_or_unreachable(vcpu);
 
 	return to_vmx(vcpu)->nested.cached_shadow_vmcs12;
 }
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ab8cfaec82d3..b10814f99a50 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -989,6 +989,12 @@ static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)
 					 lockdep_is_held(&kvm->slots_lock));
 }
 
+static inline void kvm_lockdep_assert_vcpu_is_locked_or_unreachable(struct kvm_vcpu *vcpu)
+{
+	lockdep_assert_once(lockdep_is_held(&vcpu->mutex) ||
+			    !refcount_read(&vcpu->kvm->users_count));
+}
+
 static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
 {
 	int num_vcpus = atomic_read(&kvm->online_vcpus);
-- 
2.55.0.rc0.799.gd6f94ed593-goog