From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57589) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cnmTe-0004RO-3j for qemu-devel@nongnu.org; Tue, 14 Mar 2017 09:27:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cnmTa-0006Bk-SS for qemu-devel@nongnu.org; Tue, 14 Mar 2017 09:27:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48198) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cnmTa-0006BI-Mg for qemu-devel@nongnu.org; Tue, 14 Mar 2017 09:26:58 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (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 DC1B93D941 for ; Tue, 14 Mar 2017 13:26:58 +0000 (UTC) From: Fam Zheng Date: Tue, 14 Mar 2017 21:26:54 +0800 Message-Id: <20170314132654.6751-1-famz@redhat.com> Subject: [Qemu-devel] [PATCH for-2.9] virtio-scsi: Fix assertion failure on dataplane handlers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini After the AioContext lock push down, there is a race between virtio_scsi_dataplane_start and those "assert(s->ctx && s->dataplane_started)", because the latter doesn't isn't wrapped in aio_context_acquire. Reproducer is simply booting a Fedora guest with an empty virtio-scsi-dataplane controller: qemu-system-x86_64 \ -drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw \ -device virtio-scsi \ -device scsi-disk,drive=root,bootindex=1 \ -object iothread,id=io \ -device virtio-scsi-pci,iothread=io \ -net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \ --enable-kvm Signed-off-by: Fam Zheng --- hw/scsi/virtio-scsi-dataplane.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c index 74c95e0..12b44b7 100644 --- a/hw/scsi/virtio-scsi-dataplane.c +++ b/hw/scsi/virtio-scsi-dataplane.c @@ -52,28 +52,40 @@ void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp) static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) { - VirtIOSCSI *s = (VirtIOSCSI *)vdev; + bool progress; + VirtIOSCSI *s = VIRTIO_SCSI(vdev); + aio_context_acquire(s->ctx); assert(s->ctx && s->dataplane_started); - return virtio_scsi_handle_cmd_vq(s, vq); + progress = virtio_scsi_handle_cmd_vq(s, vq); + aio_context_release(s->ctx); + return progress; } static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) { + bool progress; VirtIOSCSI *s = VIRTIO_SCSI(vdev); + aio_context_acquire(s->ctx); assert(s->ctx && s->dataplane_started); - return virtio_scsi_handle_ctrl_vq(s, vq); + progress = virtio_scsi_handle_ctrl_vq(s, vq); + aio_context_release(s->ctx); + return progress; } static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev, VirtQueue *vq) { + bool progress; VirtIOSCSI *s = VIRTIO_SCSI(vdev); + aio_context_acquire(s->ctx); assert(s->ctx && s->dataplane_started); - return virtio_scsi_handle_event_vq(s, vq); + progress = virtio_scsi_handle_event_vq(s, vq); + aio_context_release(s->ctx); + return progress; } static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n, -- 2.9.3