Subject: [PATCH v2 19/28] KVM: s390: Prepare kvm-s390 for a second kvm module

From: Steffen Eiden <[email-masked]>
Date: Tue, 28 Apr 2026 17:56:11 +0200

The second KVM module will have a different Kconfig set.
When both modules are compiled the Kconfig sets get merged and
the native s390 KVM needs to implement functionality required by
the respective config options. Ensure that s390-KVM will still compile.

Signed-off-by: Steffen Eiden <[email-masked]>
---
 arch/s390/kvm/s390/s390.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c
index 0e325b47d40e..5373b2347651 100644
--- a/arch/s390/kvm/s390/s390.c
+++ b/arch/s390/kvm/s390/s390.c
@@ -5677,6 +5677,14 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
 	return gmap_unmap_gfn_range(kvm->arch.gmap, range->slot, range->start, range->end);
 }
 
+#ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
+/* Make s390 compile if arm64-on-s390 is selected */
+int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+#endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */
+
 static inline unsigned long nonhyp_mask(int i)
 {
 	unsigned int nonhyp_fai = (sclp.hmfai << i * 2) >> 30;
-- 
2.51.0