From patchwork Thu Mar 17 10:01:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 598970 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 3qQkfN4sRxz9sCk for ; Thu, 17 Mar 2016 21:11:40 +1100 (AEDT) Received: from localhost ([::1]:33870 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agUu2-0004S4-ET for incoming@patchwork.ozlabs.org; Thu, 17 Mar 2016 06:11:38 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57431) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agUtd-0003th-Kg for qemu-devel@nongnu.org; Thu, 17 Mar 2016 06:11:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1agUtX-0006KG-IL for qemu-devel@nongnu.org; Thu, 17 Mar 2016 06:11:13 -0400 Received: from e06smtp09.uk.ibm.com ([195.75.94.105]:52482) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agUtX-0006KB-8h for qemu-devel@nongnu.org; Thu, 17 Mar 2016 06:11:07 -0400 Received: from localhost by e06smtp09.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 17 Mar 2016 10:11:04 -0000 X-IBM-Helo: d06dlp02.portsmouth.uk.ibm.com X-IBM-MailFrom: cornelia.huck@de.ibm.com X-IBM-RcptTo: qemu-devel@nongnu.org Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 0D02F21903BD for ; Thu, 17 Mar 2016 10:01:20 +0000 (GMT) Received: from d06av07.portsmouth.uk.ibm.com (d06av07.portsmouth.uk.ibm.com [9.149.37.248]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u2HA1cil5243346 for ; Thu, 17 Mar 2016 10:01:38 GMT Received: from d06av07.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av07.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u2HA1b4Z032756 for ; Thu, 17 Mar 2016 06:01:37 -0400 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d06av07.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u2HA1ace032651 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA256 bits=256 verify=NO); Thu, 17 Mar 2016 06:01:36 -0400 From: Cornelia Huck To: qemu-devel@nongnu.org Date: Thu, 17 Mar 2016 11:01:28 +0100 Message-Id: <1458208893-15949-2-git-send-email-cornelia.huck@de.ibm.com> X-Mailer: git-send-email 2.6.5 In-Reply-To: <1458208893-15949-1-git-send-email-cornelia.huck@de.ibm.com> References: <1458208893-15949-1-git-send-email-cornelia.huck@de.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16031710-0037-0000-0000-000006520CEC X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 195.75.94.105 Cc: famz@redhat.com, mst@redhat.com, borntraeger@de.ibm.com, stefanha@redhat.com, Cornelia Huck , pbonzini@redhat.com Subject: [Qemu-devel] [PATCH RFC 1/6] virtio-bus: common ioeventfd infrastructure 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 Introduce a set of ioeventfd callbacks on the virtio-bus level that can be implemented by the individual transports. At the virtio-bus level, do common handling for host notifiers (which is actually most of it). Two things of note: - We always iterate over all possible virtio queues, even though ccw (currently) has a lower limit. It does not really matter in this place. - We allow for the virtio-bus caller to pass an "assign" argument down when stopping ioeventfd, which the old interface did not allow. Signed-off-by: Cornelia Huck --- hw/virtio/virtio-bus.c | 108 +++++++++++++++++++++++++++++++++++++++++ include/hw/virtio/virtio-bus.h | 14 ++++++ 2 files changed, 122 insertions(+) diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c index 574f0e2..501300f 100644 --- a/hw/virtio/virtio-bus.c +++ b/hw/virtio/virtio-bus.c @@ -146,6 +146,114 @@ void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config) } } +static int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus, + int n, bool assign, bool set_handler) +{ + VirtIODevice *vdev = virtio_bus_get_device(bus); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); + VirtQueue *vq = virtio_get_queue(vdev, n); + EventNotifier *notifier = virtio_queue_get_host_notifier(vq); + int r = 0; + + if (assign) { + r = event_notifier_init(notifier, 1); + if (r < 0) { + error_report("%s: unable to init event notifier: %d", __func__, r); + return r; + } + virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler); + r = k->ioeventfd_assign(proxy, notifier, n, assign); + if (r < 0) { + error_report("%s: unable to assign ioeventfd: %d", __func__, r); + virtio_queue_set_host_notifier_fd_handler(vq, false, false); + event_notifier_cleanup(notifier); + return r; + } + } else { + virtio_queue_set_host_notifier_fd_handler(vq, false, false); + k->ioeventfd_assign(proxy, notifier, n, assign); + event_notifier_cleanup(notifier); + } + return r; +} + +void virtio_bus_start_ioeventfd(VirtioBusState *bus) +{ + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); + DeviceState *proxy = DEVICE(BUS(bus)->parent); + VirtIODevice *vdev; + int n, r; + + if (!k->ioeventfd_started || k->ioeventfd_started(proxy)) { + return; + } + if (!k->ioeventfd_disabled(proxy)) { + return; + } + vdev = virtio_bus_get_device(bus); + for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { + if (!virtio_queue_get_num(vdev, n)) { + continue; + } + r = set_host_notifier_internal(proxy, bus, n, true, true); + if (r < 0) { + goto assign_error; + } + } + k->ioeventfd_set_started(proxy, true, false); + return; + +assign_error: + while (--n >= 0) { + if (!virtio_queue_get_num(vdev, n)) { + continue; + } + + r = set_host_notifier_internal(proxy, bus, n, false, false); + assert(r >= 0); + } + k->ioeventfd_set_started(proxy, false, true); + error_report("%s: failed. Fallback to userspace (slower).", __func__); +} + +void virtio_bus_stop_ioeventfd(VirtioBusState *bus, bool assign) +{ + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); + DeviceState *proxy = DEVICE(BUS(bus)->parent); + VirtIODevice *vdev; + int n, r; + + if (!k->ioeventfd_started || !k->ioeventfd_started(proxy)) { + return; + } + vdev = virtio_bus_get_device(bus); + for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { + if (!virtio_queue_get_num(vdev, n)) { + continue; + } + r = set_host_notifier_internal(proxy, bus, n, assign, false); + assert(r >= 0); + } + k->ioeventfd_set_started(proxy, false, false); +} + +int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign) +{ + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); + DeviceState *proxy = DEVICE(BUS(bus)->parent); + + if (!k->ioeventfd_started) { + return -ENOSYS; + } + /* Stop using the generic ioeventfd, we are doing eventfd handling + * ourselves below */ + k->ioeventfd_set_disabled(proxy, assign); + if (assign) { + virtio_bus_stop_ioeventfd(bus, assign); + } + return set_host_notifier_internal(proxy, bus, n, assign, false); +} + static char *virtio_bus_get_dev_path(DeviceState *dev) { BusState *bus = qdev_get_parent_bus(dev); diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h index 3f2c136..0281cbf 100644 --- a/include/hw/virtio/virtio-bus.h +++ b/include/hw/virtio/virtio-bus.h @@ -71,6 +71,16 @@ typedef struct VirtioBusClass { void (*device_unplugged)(DeviceState *d); int (*query_nvectors)(DeviceState *d); /* + * ioeventfd handling: if the transport implements ioeventfd_started, + * it must implement the other ioeventfd callbacks as well + */ + bool (*ioeventfd_started)(DeviceState *d); + void (*ioeventfd_set_started)(DeviceState *d, bool started, bool err); + bool (*ioeventfd_disabled)(DeviceState *d); + void (*ioeventfd_set_disabled)(DeviceState *d, bool disabled); + int (*ioeventfd_assign)(DeviceState *d, EventNotifier *notifier, + int n, bool assign); + /* * Does the transport have variable vring alignment? * (ie can it ever call virtio_queue_set_align()?) * Note that changing this will break migration for this transport. @@ -111,4 +121,8 @@ static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus) return (VirtIODevice *)qdev; } +void virtio_bus_start_ioeventfd(VirtioBusState *bus); +void virtio_bus_stop_ioeventfd(VirtioBusState *bus, bool assign); +int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign); + #endif /* VIRTIO_BUS_H */