From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH v2 06/12] KVM: mark kvm->buses as empty once they were destroyed Date: Thu, 26 Mar 2015 22:31:51 -0300 Message-ID: <20150327013151.GA2882@amt.cnet> References: <1427126309-11223-1-git-send-email-andre.przywara@arm.com> <1427126309-11223-7-git-send-email-andre.przywara@arm.com> <5512EBB9.2050304@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andre Przywara , "christoffer.dall@linaro.org" , "pbonzini@redhat.com" , "kvmarm@lists.cs.columbia.edu" , "n.nikolaev@virtualopensystems.com" , "eric.auger@linaro.org" , "kvm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" To: Marc Zyngier Return-path: Received: from mx1.redhat.com ([209.132.183.28]:35103 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752513AbbC0BcH (ORCPT ); Thu, 26 Mar 2015 21:32:07 -0400 Content-Disposition: inline In-Reply-To: <5512EBB9.2050304@arm.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Mar 25, 2015 at 05:09:13PM +0000, Marc Zyngier wrote: > On 23/03/15 15:58, Andre Przywara wrote: > > In kvm_destroy_vm() we call kvm_io_bus_destroy() pretty early, > > especially before calling kvm_arch_destroy_vm(). To avoid > > unregistering devices from the already destroyed bus, let's mark > > the bus with NULL to let other users know it has been destroyed > > already. > > This avoids a crash on a VM shutdown with the VGIC using the > > kvm_io_bus later (the unregistering is in there to be able to roll > > back a faulting init). > > > > Signed-off-by: Andre Przywara > > That seems sensible, but I don't see why nobody else hits that. What are > we doing differently? > > Otherwise, > > Reviewed-by: Marc Zyngier > > Paolo, Marcelo, can we have your Ack on this? > > Thanks, > > M. > > > --- > > virt/kvm/kvm_main.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > > index 8c7ab0b..6f164eb 100644 > > --- a/virt/kvm/kvm_main.c > > +++ b/virt/kvm/kvm_main.c > > @@ -604,8 +604,10 @@ static void kvm_destroy_vm(struct kvm *kvm) > > list_del(&kvm->vm_list); > > spin_unlock(&kvm_lock); > > kvm_free_irq_routing(kvm); > > - for (i = 0; i < KVM_NR_BUSES; i++) > > + for (i = 0; i < KVM_NR_BUSES; i++) { > > kvm_io_bus_destroy(kvm->buses[i]); > > + kvm->buses[i] = NULL; > > + } > > kvm_coalesced_mmio_free(kvm); > > #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) > > mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm); > > > > > -- > Jazz is not dead. It just smells funny... Reviewed-by: Marcelo Tosatti