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authorEric Farman <farman@linux.ibm.com>2026-02-25 18:20:13 +0300
committerJanosch Frank <frankja@linux.ibm.com>2026-03-31 11:36:51 +0300
commit2623c96f1172ae249b67de1dfc4eacebc8673876 (patch)
treea2b8f4e1ccec94e41d7f5d6c6930d24d8b7da4cd
parent11439c4635edd669ae435eec308f4ab8a0804808 (diff)
downloadlinux-2623c96f1172ae249b67de1dfc4eacebc8673876.tar.xz
KVM: s390: only deliver service interrupt with payload
Routine __inject_service() may set both the SERVICE and SERVICE_EV pending bits, and in the case of a pure service event the corresponding trip through __deliver_service_ev() will clear the SERVICE_EV bit only. This necessitates an additional trip through __deliver_service() for the other pending interrupt bit, however it is possible that the external interrupt parameters are zero and there is nothing to be delivered to the guest. To avoid sending empty data to the guest, let's only write out the SCLP data when there is something for the guest to do, otherwise bail out. Signed-off-by: Eric Farman <farman@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
-rw-r--r--arch/s390/kvm/interrupt.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 18932a65ca68..dd0413387a9e 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -956,6 +956,9 @@ static int __must_check __deliver_service(struct kvm_vcpu *vcpu)
set_bit(IRQ_PEND_EXT_SERVICE, &fi->masked_irqs);
spin_unlock(&fi->lock);
+ if (!ext.ext_params)
+ return 0;
+
VCPU_EVENT(vcpu, 4, "deliver: sclp parameter 0x%x",
ext.ext_params);
vcpu->stat.deliver_service_signal++;