From patchwork Thu Sep 6 05:43:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 10589885 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AC8CF6CB for ; Thu, 6 Sep 2018 05:51:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9B07F2A382 for ; Thu, 6 Sep 2018 05:51:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8CAD72A55B; Thu, 6 Sep 2018 05:51:34 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1FF3B2A382 for ; Thu, 6 Sep 2018 05:51:34 +0000 (UTC) Received: from localhost ([::1]:59484 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fxnCX-0003WZ-GW for patchwork-qemu-devel@patchwork.kernel.org; Thu, 06 Sep 2018 01:51:33 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59270) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fxn8I-00087u-In for qemu-devel@nongnu.org; Thu, 06 Sep 2018 01:47:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fxn5H-0007xl-0K for qemu-devel@nongnu.org; Thu, 06 Sep 2018 01:44:03 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53688 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fxn5G-0007ua-Qi for qemu-devel@nongnu.org; Thu, 06 Sep 2018 01:44:02 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4EFFE40241C0; Thu, 6 Sep 2018 05:44:02 +0000 (UTC) Received: from lemon.usersys.redhat.com (ovpn-12-55.pek2.redhat.com [10.72.12.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id D6B1D2022EEE; Thu, 6 Sep 2018 05:43:56 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Thu, 6 Sep 2018 13:43:37 +0800 Message-Id: <20180906054340.28988-2-famz@redhat.com> In-Reply-To: <20180906054340.28988-1-famz@redhat.com> References: <20180906054340.28988-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 06 Sep 2018 05:44:02 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 06 Sep 2018 05:44:02 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'famz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v2 1/4] virtio: update MemoryRegionCaches when guest negotiates features X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Thomas Huth , Fam Zheng , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Gerd Hoffmann , Samuel Thibault , Paolo Bonzini , =?utf-8?q?Alex_Benn=C3=A9e?= , Brad Smith Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Paolo Bonzini Because the cache is sized to include the rings and the event indices, negotiating the VIRTIO_RING_F_EVENT_IDX feature will result in the size of the cache changing. And because MemoryRegionCache accesses are range-checked, if we skip this we end up with an assertion failure. This happens with OpenBSD 6.3. Reported-by: Fam Zheng Fixes: 97cd965c070152bc626c7507df9fb356bbe1cd81 Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini Signed-off-by: Fam Zheng --- hw/virtio/virtio.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index d4e4d98b59..f6a588ab57 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2006,14 +2006,25 @@ static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) int virtio_set_features(VirtIODevice *vdev, uint64_t val) { - /* + int ret; + /* * The driver must not attempt to set features after feature negotiation * has finished. */ if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { return -EINVAL; } - return virtio_set_features_nocheck(vdev, val); + ret = virtio_set_features_nocheck(vdev, val); + if (!ret && virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { + /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */ + int i; + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { + if (vdev->vq[i].vring.num != 0) { + virtio_init_region_cache(vdev, i); + } + } + } + return ret; } int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)