From: Collin Walling <walling@xxxxxxxxxxxxx> 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 <walling@xxxxxxxxxxxxx> Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211027025451.290124-1-walling@xxxxxxxxxxxxx [borntraeger@xxxxxxxxxx]: change debug level to 3 Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> --- 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 6482ea9139bb..c6257f625929 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -4255,6 +4255,7 @@ 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, 3, "setting cpnc to %d", vcpu->arch.diag318_info.cpnc); } /* * If userspace sets the riccb (e.g. after migration) to a valid state, -- 2.31.1