KVM: s390: log runtime instrumentation enablement

We handle runtime instrumentation enablement either lazy or via
sync_regs on migration. Make sure to add a debug log entry for that
per CPU on the first occurrence.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

2 files changed, 9 insertions, 6 deletions

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index fd6cd05bb6a7..5fda4686e817 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2719,6 +2719,9 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
 
 static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
+        struct runtime_instr_cb *riccb;
+
+        riccb = (struct runtime_instr_cb *) &kvm_run->s.regs.riccb;
         vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;
         vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;
         if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX)
@@ -2747,12 +2750,11 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
          * we should enable RI here instead of doing the lazy enablement.
          */
         if ((kvm_run->kvm_dirty_regs & KVM_SYNC_RICCB) &&
-            test_kvm_facility(vcpu->kvm, 64)) {
-                struct runtime_instr_cb *riccb =
-                        (struct runtime_instr_cb *) &kvm_run->s.regs.riccb;
-
-                if (riccb->valid)
-                        vcpu->arch.sie_block->ecb3 |= 0x01;
+            test_kvm_facility(vcpu->kvm, 64) &&
+            riccb->valid &&
+            !(vcpu->arch.sie_block->ecb3 & 0x01)) {
+                VCPU_EVENT(vcpu, 3, "%s", "ENABLE: RI (sync_regs)");
+                vcpu->arch.sie_block->ecb3 |= 0x01;
         }
         save_access_regs(vcpu->arch.host_acrs);
         restore_access_regs(vcpu->run->s.regs.acrs);
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 64b6a309f2c4..93d6cde8c3ea 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -37,6 +37,7 @@
 static int handle_ri(struct kvm_vcpu *vcpu)
 {
         if (test_kvm_facility(vcpu->kvm, 64)) {
+                VCPU_EVENT(vcpu, 3, "%s", "ENABLE: RI (lazy)");
                 vcpu->arch.sie_block->ecb3 |= 0x01;
                 kvm_s390_retry_instr(vcpu);
                 return 0;