From: Yi Wang Date: Mon, 6 May 2024 10:17:51 +0000 (+0800) Subject: KVM: s390: Don't re-setup dummy routing when KVM_CREATE_IRQCHIP X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c4201bd24f4ae80760ecdcf6c0d261ca867ba4ca;p=linux.git KVM: s390: Don't re-setup dummy routing when KVM_CREATE_IRQCHIP Now that KVM sets up empty irq routing in kvm_create_vm(), there's no need to setup dummy routing when KVM_CREATE_IRQCHIP. Note, userspace could very theoretically use KVM_CREATE_IRQCHIP after KVM_SET_GSI_ROUTING to reset to empty IRQ routing, but it's extremely unlikely any VMM does that, e.g. the main reason s390 does anything for KVM_CREATE_IRQCHIP is to that s390 doesn't need to be special cased by the VMM. Signed-off-by: Yi Wang Acked-by: Christian Borntraeger Link: https://lore.kernel.org/r/20240506101751.3145407-4-foxywang@tencent.com [sean: keep use_irqchip check, call out KVM_SET_GSI_ROUTING impact] Signed-off-by: Sean Christopherson --- diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 82e9631cd9ef..4641083ee100 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2996,14 +2996,9 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) break; } case KVM_CREATE_IRQCHIP: { - struct kvm_irq_routing_entry routing; - r = -EINVAL; - if (kvm->arch.use_irqchip) { - /* Set up dummy routing. */ - memset(&routing, 0, sizeof(routing)); - r = kvm_set_irq_routing(kvm, &routing, 0, 0); - } + if (kvm->arch.use_irqchip) + r = 0; break; } case KVM_SET_DEVICE_ATTR: {