From patchwork Thu Mar 25 15:07:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 12164273 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8356C433C1 for ; Thu, 25 Mar 2021 15:12:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6C69F61A13 for ; Thu, 25 Mar 2021 15:12:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C69F61A13 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:41656 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lPRel-0001ig-As for qemu-devel@archiver.kernel.org; Thu, 25 Mar 2021 11:12:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35024) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lPRaZ-0004p6-J5 for qemu-devel@nongnu.org; Thu, 25 Mar 2021 11:07:59 -0400 Received: from us-smtp-delivery-44.mimecast.com ([207.211.30.44]:58453) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lPRaY-0007ij-2S for qemu-devel@nongnu.org; Thu, 25 Mar 2021 11:07:59 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-179-ShAsmauJOzyVu0eZblyGsg-1; Thu, 25 Mar 2021 11:07:55 -0400 X-MC-Unique: ShAsmauJOzyVu0eZblyGsg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3E13380BCA6; Thu, 25 Mar 2021 15:07:53 +0000 (UTC) Received: from bahia.redhat.com (ovpn-113-20.ams2.redhat.com [10.36.113.20]) by smtp.corp.redhat.com (Postfix) with ESMTP id 42ECB5C649; Thu, 25 Mar 2021 15:07:51 +0000 (UTC) From: Greg Kurz To: qemu-devel@nongnu.org Subject: [RFC 3/8] virtio: Add API to batch set host notifiers Date: Thu, 25 Mar 2021 16:07:30 +0100 Message-Id: <20210325150735.1098387-4-groug@kaod.org> In-Reply-To: <20210325150735.1098387-1-groug@kaod.org> References: <20210325150735.1098387-1-groug@kaod.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kaod.org Received-SPF: softfail client-ip=207.211.30.44; envelope-from=groug@kaod.org; helo=us-smtp-delivery-44.mimecast.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fam Zheng , Kevin Wolf , qemu-block@nongnu.org, "Michael S. Tsirkin" , Greg Kurz , Max Reitz , Stefan Hajnoczi , Paolo Bonzini , David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Introduce VirtioBusClass methods to begin and commit a transaction of setting/unsetting host notifiers. These handlers will be implemented by virtio-pci to batch addition and deletion of ioeventfds for multiqueue devices like virtio-scsi-pci or virtio-blk-pci. Convert virtio_bus_set_host_notifiers() to use these handlers. Note that virtio_bus_cleanup_host_notifier() closes eventfds, which could still be passed to the KVM_IOEVENTFD ioctl() when the transaction ends and fail with EBADF. The cleanup of the host notifiers is thus pushed to a separate loop in virtio_bus_unset_and_cleanup_host_notifiers(), after transaction commit. Signed-off-by: Greg Kurz --- include/hw/virtio/virtio-bus.h | 4 ++++ hw/virtio/virtio-bus.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h index 6d1e4ee3e886..99704b2c090a 100644 --- a/include/hw/virtio/virtio-bus.h +++ b/include/hw/virtio/virtio-bus.h @@ -82,6 +82,10 @@ struct VirtioBusClass { */ int (*ioeventfd_assign)(DeviceState *d, EventNotifier *notifier, int n, bool assign); + + void (*ioeventfd_assign_begin)(DeviceState *d); + void (*ioeventfd_assign_commit)(DeviceState *d); + /* * Whether queue number n is enabled. */ diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c index c9e7cdb5c161..156484c4ca14 100644 --- a/hw/virtio/virtio-bus.c +++ b/hw/virtio/virtio-bus.c @@ -295,6 +295,28 @@ int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign) return r; } +static void virtio_bus_set_host_notifier_begin(VirtioBusState *bus) +{ + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); + DeviceState *proxy = DEVICE(BUS(bus)->parent); + + if (k->ioeventfd_assign_begin) { + assert(k->ioeventfd_assign_commit); + k->ioeventfd_assign_begin(proxy); + } +} + +static void virtio_bus_set_host_notifier_commit(VirtioBusState *bus) +{ + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); + DeviceState *proxy = DEVICE(BUS(bus)->parent); + + if (k->ioeventfd_assign_commit) { + assert(k->ioeventfd_assign_begin); + k->ioeventfd_assign_commit(proxy); + } +} + void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n) { VirtIODevice *vdev = virtio_bus_get_device(bus); @@ -308,6 +330,7 @@ void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n) event_notifier_cleanup(notifier); } +/* virtio_bus_set_host_notifier_begin() must have been called */ static void virtio_bus_unset_and_cleanup_host_notifiers(VirtioBusState *bus, int nvqs, int n_offset) { @@ -315,6 +338,10 @@ static void virtio_bus_unset_and_cleanup_host_notifiers(VirtioBusState *bus, for (i = 0; i < nvqs; i++) { virtio_bus_set_host_notifier(bus, i + n_offset, false); + } + /* Let address_space_update_ioeventfds() run before closing ioeventfds */ + virtio_bus_set_host_notifier_commit(bus); + for (i = 0; i < nvqs; i++) { virtio_bus_cleanup_host_notifier(bus, i + n_offset); } } @@ -327,17 +354,24 @@ int virtio_bus_set_host_notifiers(VirtioBusState *bus, int nvqs, int n_offset, int rc; if (assign) { + virtio_bus_set_host_notifier_begin(bus); + for (i = 0; i < nvqs; i++) { rc = virtio_bus_set_host_notifier(bus, i + n_offset, true); if (rc != 0) { warn_report_once("%s: Failed to set host notifier (%s).\n", vdev->name, strerror(-rc)); + /* This also calls virtio_bus_set_host_notifier_commit() */ virtio_bus_unset_and_cleanup_host_notifiers(bus, i, n_offset); return rc; } } + + virtio_bus_set_host_notifier_commit(bus); } else { + virtio_bus_set_host_notifier_begin(bus); + /* This also calls virtio_bus_set_host_notifier_commit() */ virtio_bus_unset_and_cleanup_host_notifiers(bus, nvqs, n_offset); }