From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-1.mimecast.com ([205.139.110.61]:44445 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728435AbgAINuP (ORCPT ); Thu, 9 Jan 2020 08:50:15 -0500 Date: Thu, 9 Jan 2020 14:50:06 +0100 From: Cornelia Huck Subject: Re: [PATCH] KVM: s390: check if kernel irqchip is actually enabled Message-ID: <20200109145006.21f0a065.cohuck@redhat.com> In-Reply-To: <20200109134713.14755-1-cohuck@redhat.com> References: <20200109134713.14755-1-cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Christian Borntraeger , Janosch Frank Cc: David Hildenbrand , kvm@vger.kernel.org, linux-s390@vger.kernel.org On Thu, 9 Jan 2020 14:47:13 +0100 Cornelia Huck wrote: > On s390, we only allow userspace to create an in-kernel irqchip > if it has first enabled the KVM_CAP_S390_IRQCHIP vm capability. > Let's assume that a userspace that enabled that capability has > created an irqchip as well. > > Fixes: 84223598778b ("KVM: s390: irq routing for adapter interrupts.") > Signed-off-by: Cornelia Huck > --- > > A more precise check would be to add a field in kvm_arch that tracks > whether an irqchip has actually been created; not sure if that is > really needed. > > Found while trying to hunt down QEMU crashes with kvm-irqchip=off; s/kvm-irqchip/kernel_irqchip/ > this is not sufficient, though. I *think* everything but irqfds > should work without kvm-irqchip as well, but have not found the problem > yet. > > --- > arch/s390/kvm/irq.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/s390/kvm/irq.h b/arch/s390/kvm/irq.h > index 484608c71dd0..30e13d031379 100644 > --- a/arch/s390/kvm/irq.h > +++ b/arch/s390/kvm/irq.h > @@ -13,7 +13,7 @@ > > static inline int irqchip_in_kernel(struct kvm *kvm) > { > - return 1; > + return !!kvm->arch.use_irqchip; > } > > #endif