From a0496b40a4ab346052aaa59a5163c10224dda01f Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda Date: Mon, 3 Aug 2026 14:40:31 +0200 Subject: [PATCH] KVM: s390: Fix overclearing ESCA in case of error If an attempt is made to create a vCPU with an already existing ID, the duplicated vCPU will be destroyed. When destroying a vCPU, its ESCA entry will be cleared. In the above scenario, the spurious duplicate vCPU is destroyed, but the ESCA entry corresponding to the original vCPU is cleared. Fix by skipping clearing the ESCA entry if the vCPU creation was not successful, i.e. if the vcpu->arch.initialized is still zero. Reviewed-by: Janosch Frank Signed-off-by: Claudio Imbrenda Fixes: abf4a71ed95f ("KVM: s390: Unlink vcpu on destroy - v2") [ Added Fixes tag while picking -- Claudio ] Message-ID: <20260803124040.126471-5-imbrenda@linux.ibm.com> --- arch/s390/kvm/interrupt.c | 2 +- arch/s390/kvm/kvm-s390.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 7514d9e2403c..bb4e72466043 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -86,7 +86,7 @@ static void sca_clear_ext_call(struct kvm_vcpu *vcpu) struct esca_block *sca = vcpu->kvm->arch.sca; union esca_sigp_ctrl *sigp_ctrl = &sca->cpu[vcpu->vcpu_id].sigp_ctrl; - if (!kvm_s390_use_sca_entries()) + if (!kvm_s390_use_sca_entries() || !vcpu->arch.initialized) return; kvm_s390_clear_cpuflags(vcpu, CPUSTAT_ECALL_PEND); diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 9be27db0a21e..5b2727d7dfd1 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3462,7 +3462,7 @@ static void sca_del_vcpu(struct kvm_vcpu *vcpu) { struct esca_block *sca = vcpu->kvm->arch.sca; - if (!kvm_s390_use_sca_entries()) + if (!kvm_s390_use_sca_entries() || !vcpu->arch.initialized) return; clear_bit_inv(vcpu->vcpu_id, (unsigned long *)sca->mcn);