From patchwork Tue Mar 14 13:34:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 9623413 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6133260492 for ; Tue, 14 Mar 2017 13:35:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 56DDB28583 for ; Tue, 14 Mar 2017 13:35:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4BFAC28585; Tue, 14 Mar 2017 13:35:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C824128583 for ; Tue, 14 Mar 2017 13:35:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752468AbdCNNfu (ORCPT ); Tue, 14 Mar 2017 09:35:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44006 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751217AbdCNNez (ORCPT ); Tue, 14 Mar 2017 09:34:55 -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 D78CC83F3E for ; Tue, 14 Mar 2017 13:34:55 +0000 (UTC) Received: from t460s.redhat.com (ovpn-116-233.ams2.redhat.com [10.36.116.233]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v2EDYqIk007130; Tue, 14 Mar 2017 09:34:54 -0400 From: David Hildenbrand To: kvm@vger.kernel.org Cc: Paolo Bonzini , rkrcmar@redhat.com, david@redhat.com Subject: [PATCH v1 01/22] KVM: x86: race between KVM_SET_GSI_ROUTING and KVM_CREATE_IRQCHIP Date: Tue, 14 Mar 2017 14:34:29 +0100 Message-Id: <20170314133450.13259-2-david@redhat.com> In-Reply-To: <20170314133450.13259-1-david@redhat.com> References: <20170314133450.13259-1-david@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 14 Mar 2017 13:34:55 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Avoid races between KVM_SET_GSI_ROUTING and KVM_CREATE_IRQCHIP by taking the kvm->lock when setting up routes. If KVM_CREATE_IRQCHIP fails, KVM_SET_GSI_ROUTING could have already set up routes pointing at pic/ioapic, being silently removed already. Signed-off-by: David Hildenbrand --- virt/kvm/kvm_main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a17d787..ad0f8b2 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3079,8 +3079,11 @@ static long kvm_vm_ioctl(struct file *filp, routing.nr * sizeof(*entries))) goto out_free_irq_routing; } + /* avoid races with KVM_CREATE_IRQCHIP on x86 */ + mutex_lock(&kvm->lock); r = kvm_set_irq_routing(kvm, entries, routing.nr, routing.flags); + mutex_unlock(&kvm->lock); out_free_irq_routing: vfree(entries); break;