Subject: [PATCH v2 4/4] KVM: PPC: Decrement module refcount if init_vm fails

From: Fabiano Rosas <[email-masked]>
Date: Mon, 24 Jan 2022 19:08:03 -0300

We increment the reference count for KVM-HV/PR before the call to
kvmppc_core_init_vm. If that function fails we need to decrement the
refcount.

Signed-off-by: Fabiano Rosas <[email-masked]>
---
Caught this while testing Nick's LPID patches by looking at
/sys/module/kvm_hv/refcnt
---
 arch/powerpc/kvm/powerpc.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 2ad0ccd202d5..4285d0eac900 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -431,6 +431,8 @@ int kvm_arch_check_processor_compat(void *opaque)
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
 	struct kvmppc_ops *kvm_ops = NULL;
+	int r;
+
 	/*
 	 * if we have both HV and PR enabled, default is HV
 	 */
@@ -456,7 +458,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 		return -ENOENT;
 
 	kvm->arch.kvm_ops = kvm_ops;
-	return kvmppc_core_init_vm(kvm);
+	r = kvmppc_core_init_vm(kvm);
+	if (r)
+		module_put(kvm->arch.kvm_ops->owner);
+	return r;
 err_out:
 	return -EINVAL;
 }
-- 
2.34.1