KVM: s390: inject PER i-fetch events on applicable icpts

In case we have to emuluate an instruction or part of it (instruction,
partial instruction, operation exception), we have to inject a PER
instruction-fetching event for that instruction, if hardware told us to do
so.

In case we retry an instruction, we must not inject the PER event.

Please note that we don't filter the events properly yet, so guest
debugging will be visible for the guest.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 14 insertions, 3 deletions

diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 9359f65c8634..850be47c4cc9 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -364,6 +364,8 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
 
 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 {
+        int rc, per_rc = 0;
+
         if (kvm_is_ucontrol(vcpu->kvm))
                 return -EOPNOTSUPP;
 
@@ -372,7 +374,8 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
         case 0x18:
                 return handle_noop(vcpu);
         case 0x04:
-                return handle_instruction(vcpu);
+                rc = handle_instruction(vcpu);
+                break;
         case 0x08:
                 return handle_prog(vcpu);
         case 0x14:
@@ -384,10 +387,18 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
         case 0x28:
                 return handle_stop(vcpu);
         case 0x2c:
-                return handle_operexc(vcpu);
+                rc = handle_operexc(vcpu);
+                break;
         case 0x38:
-                return handle_partial_execution(vcpu);
+                rc = handle_partial_execution(vcpu);
+                break;
         default:
                 return -EOPNOTSUPP;
         }
+
+        /* process PER, also if the instrution is processed in user space */
+        if (vcpu->arch.sie_block->icptstatus & 0x02 &&
+            (!rc || rc == -EOPNOTSUPP))
+                per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
+        return per_rc ? per_rc : rc;
 }