From patchwork Wed Oct 15 13:15:25 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 399979 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id E48A314009E for ; Thu, 16 Oct 2014 00:16:48 +1100 (EST) Received: from localhost ([::1]:44686 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XeORb-00023b-0Q for incoming@patchwork.ozlabs.org; Wed, 15 Oct 2014 09:16:47 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40242) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XeOQe-0000Ym-GA for qemu-devel@nongnu.org; Wed, 15 Oct 2014 09:15:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XeOQU-0003f8-Bt for qemu-devel@nongnu.org; Wed, 15 Oct 2014 09:15:48 -0400 Received: from e06smtp10.uk.ibm.com ([195.75.94.106]:45592) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XeOQT-0003eG-T9 for qemu-devel@nongnu.org; Wed, 15 Oct 2014 09:15:38 -0400 Received: from /spool/local by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 15 Oct 2014 14:15:36 +0100 Received: from d06dlp03.portsmouth.uk.ibm.com (9.149.20.15) by e06smtp10.uk.ibm.com (192.168.101.140) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 15 Oct 2014 14:15:33 +0100 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 230FF1B0806E for ; Wed, 15 Oct 2014 14:16:51 +0100 (BST) Received: from d06av03.portsmouth.uk.ibm.com (d06av03.portsmouth.uk.ibm.com [9.149.37.213]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s9FDFWeb64815242 for ; Wed, 15 Oct 2014 13:15:32 GMT Received: from d06av03.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s9FDFWld005186 for ; Wed, 15 Oct 2014 07:15:32 -0600 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id s9FDFTGf005084; Wed, 15 Oct 2014 07:15:31 -0600 From: Cornelia Huck To: pbonzini@redhat.com, famz@redhat.com Date: Wed, 15 Oct 2014 15:15:25 +0200 Message-Id: <1413378926-52442-3-git-send-email-cornelia.huck@de.ibm.com> X-Mailer: git-send-email 1.8.5.5 In-Reply-To: <1413378926-52442-1-git-send-email-cornelia.huck@de.ibm.com> References: <1413378926-52442-1-git-send-email-cornelia.huck@de.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14101513-0041-0000-0000-000001AD89E5 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 195.75.94.106 Cc: Cornelia Huck , qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH 2/3] virtio-scsi: dataplane: fail setup gracefully X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org The dataplane code is currently doing a hard exit on various setup failures. In practice, this may mean that a guest suddenly dies after a dataplane device failed to come up (e.g., when a file descriptor limit is hit for the nth device). Let's just try to unwind the setup instead and return. Signed-off-by: Cornelia Huck --- hw/scsi/virtio-scsi-dataplane.c | 73 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 64 insertions(+), 9 deletions(-) diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c index e068297..445219c 100644 --- a/hw/scsi/virtio-scsi-dataplane.c +++ b/hw/scsi/virtio-scsi-dataplane.c @@ -52,7 +52,7 @@ static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s, if (rc != 0) { fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n", rc); - exit(1); + return NULL; } r->host_notifier = *virtio_queue_get_host_notifier(vq); r->guest_notifier = *virtio_queue_get_guest_notifier(vq); @@ -62,9 +62,15 @@ static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s, if (!vring_setup(&r->vring, VIRTIO_DEVICE(s), n)) { fprintf(stderr, "virtio-scsi: VRing setup failed\n"); - exit(1); + goto fail_vring; } return r; + +fail_vring: + aio_set_event_notifier(s->ctx, &r->host_notifier, NULL); + k->set_host_notifier(qbus->parent, n, false); + g_slice_free(VirtIOSCSIVring, r); + return NULL; } VirtIOSCSIReq *virtio_scsi_pop_req_vring(VirtIOSCSI *s, @@ -140,6 +146,40 @@ static void virtio_scsi_iothread_handle_cmd(EventNotifier *notifier) } } +/* assumes s->ctx held */ +static void virtio_scsi_clear_aio(VirtIOSCSI *s) +{ + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); + int i; + + if (s->ctrl_vring) { + aio_set_event_notifier(s->ctx, &s->ctrl_vring->host_notifier, NULL); + } + if (s->event_vring) { + aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier, NULL); + } + for (i = 0; i < vs->conf.num_queues && s->cmd_vrings[i]; i++) { + aio_set_event_notifier(s->ctx, &s->cmd_vrings[i]->host_notifier, NULL); + } +} + +static void virtio_scsi_vring_teardown(VirtIOSCSI *s) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(s); + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); + int i; + + if (s->ctrl_vring) { + vring_teardown(&s->ctrl_vring->vring, vdev, 0); + } + if (s->event_vring) { + vring_teardown(&s->event_vring->vring, vdev, 1); + } + for (i = 0; i < vs->conf.num_queues && s->cmd_vrings[i]; i++) { + vring_teardown(&s->cmd_vrings[i]->vring, vdev, 2 + i); + } +} + /* Context: QEMU global mutex held */ void virtio_scsi_dataplane_start(VirtIOSCSI *s) { @@ -162,27 +202,47 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s) if (rc != 0) { fprintf(stderr, "virtio-scsi: Failed to set guest notifiers (%d), " "ensure -enable-kvm is set\n", rc); - exit(1); + goto fail_guest_notifiers; } aio_context_acquire(s->ctx); s->ctrl_vring = virtio_scsi_vring_init(s, vs->ctrl_vq, virtio_scsi_iothread_handle_ctrl, 0); + if (!s->ctrl_vring) { + goto fail_vrings; + } s->event_vring = virtio_scsi_vring_init(s, vs->event_vq, virtio_scsi_iothread_handle_event, 1); + if (!s->event_vring) { + goto fail_vrings; + } s->cmd_vrings = g_malloc0(sizeof(VirtIOSCSIVring) * vs->conf.num_queues); for (i = 0; i < vs->conf.num_queues; i++) { s->cmd_vrings[i] = virtio_scsi_vring_init(s, vs->cmd_vqs[i], virtio_scsi_iothread_handle_cmd, i + 2); + if (!s->cmd_vrings[i]) { + goto fail_vrings; + } } aio_context_release(s->ctx); s->dataplane_starting = false; s->dataplane_started = true; + +fail_vrings: + virtio_scsi_clear_aio(s); + aio_context_release(s->ctx); + virtio_scsi_vring_teardown(s); + for (i = 0; i < vs->conf.num_queues + 2; i++) { + k->set_host_notifier(qbus->parent, i, false); + } + k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false); +fail_guest_notifiers: + s->dataplane_starting = false; } /* Context: QEMU global mutex held */ @@ -190,7 +250,6 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); - VirtIODevice *vdev = VIRTIO_DEVICE(s); VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); int i; @@ -215,11 +274,7 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s) /* Sync vring state back to virtqueue so that non-dataplane request * processing can continue when we disable the host notifier below. */ - vring_teardown(&s->ctrl_vring->vring, vdev, 0); - vring_teardown(&s->event_vring->vring, vdev, 1); - for (i = 0; i < vs->conf.num_queues; i++) { - vring_teardown(&s->cmd_vrings[i]->vring, vdev, 2 + i); - } + virtio_scsi_vring_teardown(s); for (i = 0; i < vs->conf.num_queues + 2; i++) { k->set_host_notifier(qbus->parent, i, false);