[PATCH v2 6/8] KVM: x86: Treat a vCPU as unreachable if its index is invalid

[Sean Christopherson]

In the "vCPU locked or unreachable" lockdep assertion, treat a vCPU as
unreachable if its index is invalid, i.e. if the vCPU is in the process of
being created.  Until the vCPU is inserted into the array of vCPUs, the
only way to get at the vCPU is via kvm_vm_ioctl_create_vcpu().  Note, the
actual index is set _before_ adding the vCPU to the array, i.e. there's no
risk of a false negative on the lockdep assertion.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
 include/linux/kvm_host.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 82696b27b145..017070b81108 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -992,6 +992,7 @@ static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)
 static inline void kvm_lockdep_assert_vcpu_is_locked_or_unreachable(struct kvm_vcpu *vcpu)
 {
 	lockdep_assert_once(lockdep_is_held(&vcpu->mutex) ||
+			    vcpu->vcpu_idx < 0 ||
 			    !refcount_read(&vcpu->kvm->users_count));
 }
 
-- 
2.54.0.1136.gdb2ca164c4-goog