[PATCH v5 01/15] KVM: s390: unregister debug feature on failing arch init

From: Michael Mueller
Date: Wed Dec 19 2018 - 14:20:22 EST


Make sure the debug feature and its allocated resources get
released upon unsuccessful architecture initialization.

A related indication of the issue will be reported as kernel
message.

Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Message-Id: <20181130143215.69496-2-mimu@xxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
Documentation/kmsg/s390/kvm | 12 ++++++++++++
arch/s390/kvm/kvm-s390.c | 17 ++++++++++++++---
2 files changed, 26 insertions(+), 3 deletions(-)
create mode 100644 Documentation/kmsg/s390/kvm

diff --git a/Documentation/kmsg/s390/kvm b/Documentation/kmsg/s390/kvm
new file mode 100644
index 000000000000..76ffe2012254
--- /dev/null
+++ b/Documentation/kmsg/s390/kvm
@@ -0,0 +1,12 @@
+/*?
+ * Text: "Failed to register FLIC rc=%d\n"
+ * Severity: Error
+ * Parameter:
+ * @1: return code of the FLIC registration call
+ * Description:
+ * The registration of the FLIC (Floating Interrupt Controller Interface)
+ * was not successful.
+ * User action:
+ * If this problem persists after a reload of the kvm kernel module, gather
+ * Linux debug data and contact your support organization.
+ */
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index fe24150ff666..d8d8e0788157 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -417,19 +417,30 @@ static void kvm_s390_cpu_feat_init(void)

int kvm_arch_init(void *opaque)
{
+ int rc;
+
kvm_s390_dbf = debug_register("kvm-trace", 32, 1, 7 * sizeof(long));
if (!kvm_s390_dbf)
return -ENOMEM;

if (debug_register_view(kvm_s390_dbf, &debug_sprintf_view)) {
- debug_unregister(kvm_s390_dbf);
- return -ENOMEM;
+ rc = -ENOMEM;
+ goto out_debug_unreg;
}

kvm_s390_cpu_feat_init();

/* Register floating interrupt controller interface. */
- return kvm_register_device_ops(&kvm_flic_ops, KVM_DEV_TYPE_FLIC);
+ rc = kvm_register_device_ops(&kvm_flic_ops, KVM_DEV_TYPE_FLIC);
+ if (rc) {
+ pr_err("Failed to register FLIC rc=%d\n", rc);
+ goto out_debug_unreg;
+ }
+ return 0;
+
+out_debug_unreg:
+ debug_unregister(kvm_s390_dbf);
+ return rc;
}

void kvm_arch_exit(void)
--
2.13.4