From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Xu Subject: [PATCH v2 1/3] KVM: x86: clear bus pointer when destroyed Date: Wed, 15 Mar 2017 16:01:17 +0800 Message-ID: <1489564879-6097-2-git-send-email-peterx@redhat.com> References: <1489564879-6097-1-git-send-email-peterx@redhat.com> Cc: David Hildenbrand , Paolo Bonzini , peterx@redhat.com, =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:49354 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751198AbdCOIBd (ORCPT ); Wed, 15 Mar 2017 04:01:33 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 832304DD7E for ; Wed, 15 Mar 2017 08:01:33 +0000 (UTC) In-Reply-To: <1489564879-6097-1-git-send-email-peterx@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: When releasing the bus, let's clear the bus pointers to mark it out. If any further device unregister happens on this bus, we know that we're done if we found the bus being released already. Signed-off-by: Peter Xu --- virt/kvm/kvm_main.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a17d787..7445566 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -727,8 +727,10 @@ 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); @@ -3579,6 +3581,14 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, struct kvm_io_bus *new_bus, *bus; bus = kvm->buses[bus_idx]; + + /* + * It's possible the bus being released before hand. If so, + * we're done here. + */ + if (!bus) + return 0; + r = -ENOENT; for (i = 0; i < bus->dev_count; i++) if (bus->range[i].dev == dev) { -- 2.7.4