Re: [PATCH v2 5/6] KVM: s390: interrupt: Fix single-stepping ISKE

From: David Hildenbrand
Date: Mon Jul 24 2023 - 04:30:24 EST


On 21.07.23 13:57, Ilya Leoshkevich wrote:
kvm_s390_skey_check_enable() does not emulate any instructions, rather,
it clears CPUSTAT_KSS and arranges for ISKE to run again. Therefore,
skip the PER check and let ISKE run happen. Otherwise a debugger will
see two single-step events on the same ISKE.

Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
---
arch/s390/kvm/intercept.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index d2f7940c5d03..8793cec066a6 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -630,8 +630,7 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
rc = handle_partial_execution(vcpu);
break;
case ICPT_KSS:
- rc = kvm_s390_skey_check_enable(vcpu);
- break;
+ return kvm_s390_skey_check_enable(vcpu);
case ICPT_MCHKREQ:
case ICPT_INT_ENABLE:
/*

Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers,

David / dhildenb