The diag 318 data contains values that denote information regarding the
guest's environment. Currently, it is unecessarily difficult to observe
this value (either manually-inserted debug statements, gdb stepping, mem
dumping etc). It's useful to observe this information to obtain an
at-a-glance view of the guest's environment, so lets add a simple VCPU
event that prints the CPNC to the s390dbf logs.

Signed-off-by: Collin Walling <redacted>
---
  arch/s390/kvm/kvm-s390.c | 1 +
  1 file changed, 1 insertion(+)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 6a6dd5e1daf6..da3ff24eabd0 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c

@@ -4254,6 +4254,7 @@ static void sync_regs_fmt2(struct kvm_vcpu *vcpu)
  	if (kvm_run->kvm_dirty_regs & KVM_SYNC_DIAG318) {
  		vcpu->arch.diag318_info.val = kvm_run->s.regs.diag318;
  		vcpu->arch.sie_block->cpnc = vcpu->arch.diag318_info.cpnc;
+		VCPU_EVENT(vcpu, 2, "setting cpnc to %d", vcpu->arch.diag318_info.cpnc);
  	}
  	/*
  	 * If userspace sets the riccb (e.g. after migration) to a valid state,