| Message ID | 20220124220803.1011673-5-farosas@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: PPC: KVM module exit fixes | expand |
Excerpts from Fabiano Rosas's message of January 25, 2022 8:08 am: > 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 <farosas@linux.ibm.com> > --- > Caught this while testing Nick's LPID patches by looking at > /sys/module/kvm_hv/refcnt Nice catch. Is this the only change in the series? You can just use kvm_ops->owner like try_module_get() does I think? Also try_module_get works on a NULL module same as module_put by the looks, so you could adjust that in this patch to remove the NULL check so it is consistent with the put. Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Thanks, Nick > --- > 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 > >
Nicholas Piggin <npiggin@gmail.com> writes: > Excerpts from Fabiano Rosas's message of January 25, 2022 8:08 am: >> 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 <farosas@linux.ibm.com> >> --- >> Caught this while testing Nick's LPID patches by looking at >> /sys/module/kvm_hv/refcnt > > Nice catch. Is this the only change in the series? Yes. > You can just use kvm_ops->owner like try_module_get() does I think? Also > try_module_get works on a NULL module same as module_put by the looks, > so you could adjust that in this patch to remove the NULL check so it > is consistent with the put. Sure, I'll send a v3.
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; }
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 <farosas@linux.ibm.com> --- 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(-)