From 4bda7deac3c0860543e60ee338b966ecccfdd116 Mon Sep 17 00:00:00 2001 From: Collin Walling Date: Tue, 26 Oct 2021 22:54:51 -0400 Subject: [PATCH 4/4] KVM: s390: add debug statement for diag 318 CPNC data 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 Acked-by: Christian Borntraeger Link: https://lore.kernel.org/r/20211027025451.290124-1-walling@linux.ibm.com [borntraeger@de.ibm.com]: change debug level to 3 Signed-off-by: Christian Borntraeger --- 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 5dda764fa16b..38179bc15efd 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -4194,6 +4194,7 @@ static void sync_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 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, -- 2.25.1