From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 45CA6C3A589 for ; Tue, 20 Aug 2019 13:40:45 +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 1D82F23401 for ; Tue, 20 Aug 2019 13:40:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1D82F23401 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37658 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i04NQ-0004ib-9D for qemu-devel@archiver.kernel.org; Tue, 20 Aug 2019 09:40:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46400) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i04MJ-0003aK-Uo for qemu-devel@nongnu.org; Tue, 20 Aug 2019 09:39:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i04MI-0001iY-AR for qemu-devel@nongnu.org; Tue, 20 Aug 2019 09:39:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37920) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i04MI-0001hr-1w for qemu-devel@nongnu.org; Tue, 20 Aug 2019 09:39:34 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 487FB4FCD9 for ; Tue, 20 Aug 2019 13:39:32 +0000 (UTC) Received: from work-vm (ovpn-117-33.ams2.redhat.com [10.36.117.33]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D36AE11C9A8; Tue, 20 Aug 2019 13:39:18 +0000 (UTC) Date: Tue, 20 Aug 2019 14:39:15 +0100 From: "Dr. David Alan Gilbert" To: Cornelia Huck Message-ID: <20190820133915.GI2867@work-vm> References: <20190816143321.20903-1-dgilbert@redhat.com> <20190816143321.20903-2-dgilbert@redhat.com> <20190818065944-mutt-send-email-mst@kernel.org> <20190820142428.7995cd89.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190820142428.7995cd89.cohuck@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 20 Aug 2019 13:39:32 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device 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: vgoyal@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Cornelia Huck (cohuck@redhat.com) wrote: > On Sun, 18 Aug 2019 07:08:31 -0400 > "Michael S. Tsirkin" wrote: > > > On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git) wrote: > > > From: "Dr. David Alan Gilbert" > > > > > > The virtio-fs virtio device provides shared file system access using > > > the FUSE protocol carried ovew virtio. > > > The actual file server is implemented in an external vhost-user-fs device > > > backend process. > > > > > > Signed-off-by: Stefan Hajnoczi > > > Signed-off-by: Sebastien Boeuf > > > Signed-off-by: Dr. David Alan Gilbert > > > --- > > > configure | 13 + > > > hw/virtio/Makefile.objs | 1 + > > > hw/virtio/vhost-user-fs.c | 297 ++++++++++++++++++++ > > > include/hw/virtio/vhost-user-fs.h | 45 +++ > > > include/standard-headers/linux/virtio_fs.h | 41 +++ > > > include/standard-headers/linux/virtio_ids.h | 1 + > > > 6 files changed, 398 insertions(+) > > > create mode 100644 hw/virtio/vhost-user-fs.c > > > create mode 100644 include/hw/virtio/vhost-user-fs.h > > > create mode 100644 include/standard-headers/linux/virtio_fs.h > > > > diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c > > > new file mode 100644 > > > index 0000000000..2753c2c07a > > > --- /dev/null > > > +++ b/hw/virtio/vhost-user-fs.c > > > @@ -0,0 +1,297 @@ > > > +/* > > > + * Vhost-user filesystem virtio device > > > + * > > > + * Copyright 2018 Red Hat, Inc. > > > + * > > > + * Authors: > > > + * Stefan Hajnoczi > > > + * > > > + * This work is licensed under the terms of the GNU GPL, version 2 or > > > + * (at your option) any later version. See the COPYING file in the > > > + * top-level directory. > > > + */ > > > + > > > +#include "qemu/osdep.h" > > > +#include > > > +#include "standard-headers/linux/virtio_fs.h" > > > +#include "qapi/error.h" > > > +#include "hw/virtio/virtio-bus.h" > > > +#include "hw/virtio/virtio-access.h" > > > +#include "qemu/error-report.h" > > > +#include "hw/virtio/vhost-user-fs.h" > > > +#include "monitor/monitor.h" > > JFYI, this needs to include hw/qdev-properties.h as well on the latest > code level. (As does the pci part.) Thanks! Updated my local version. Dave > > > + > > > +static void vuf_get_config(VirtIODevice *vdev, uint8_t *config) > > > +{ > > > + VHostUserFS *fs = VHOST_USER_FS(vdev); > > > + struct virtio_fs_config fscfg = {}; > > > + > > > + memcpy((char *)fscfg.tag, fs->conf.tag, > > > + MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag))); > > > + > > > + virtio_stl_p(vdev, &fscfg.num_queues, fs->conf.num_queues); > > > + > > > + memcpy(config, &fscfg, sizeof(fscfg)); > > > +} > > > + > > > +static void vuf_start(VirtIODevice *vdev) > > > +{ > > > + VHostUserFS *fs = VHOST_USER_FS(vdev); > > > + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); > > > + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); > > > + int ret; > > > + int i; > > > + > > > + if (!k->set_guest_notifiers) { > > > + error_report("binding does not support guest notifiers"); > > > + return; > > > + } > > > + > > > + ret = vhost_dev_enable_notifiers(&fs->vhost_dev, vdev); > > > + if (ret < 0) { > > > + error_report("Error enabling host notifiers: %d", -ret); > > > + return; > > > + } > > > + > > > + ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, true); > > > + if (ret < 0) { > > > + error_report("Error binding guest notifier: %d", -ret); > > > + goto err_host_notifiers; > > > + } > > > + > > > + fs->vhost_dev.acked_features = vdev->guest_features; > > > + ret = vhost_dev_start(&fs->vhost_dev, vdev); > > > + if (ret < 0) { > > > + error_report("Error starting vhost: %d", -ret); > > > + goto err_guest_notifiers; > > > + } > > > + > > > + /* > > > + * guest_notifier_mask/pending not used yet, so just unmask > > > + * everything here. virtio-pci will do the right thing by > > > + * enabling/disabling irqfd. > > Referring to 'virtio-pci' seems a bit suspicious :) Should that be 'the > transport'? (And 'the right thing' is not really self-explanatory...) > > (I have wired it up for virtio-ccw, but have not actually tried it out. > Will send it out once I did.) > > > > + */ > > > + for (i = 0; i < fs->vhost_dev.nvqs; i++) { > > > + vhost_virtqueue_mask(&fs->vhost_dev, vdev, i, false); > > > + } > > > + > > > + return; > > > + > > > +err_guest_notifiers: > > > + k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false); > > > +err_host_notifiers: > > > + vhost_dev_disable_notifiers(&fs->vhost_dev, vdev); > > > +} > > (...) > > > > +static void vuf_device_realize(DeviceState *dev, Error **errp) > > > +{ > > > + VirtIODevice *vdev = VIRTIO_DEVICE(dev); > > > + VHostUserFS *fs = VHOST_USER_FS(dev); > > > + unsigned int i; > > > + size_t len; > > > + int ret; > > > + > > > + if (!fs->conf.chardev.chr) { > > > + error_setg(errp, "missing chardev"); > > > + return; > > > + } > > > + > > > + if (!fs->conf.tag) { > > > + error_setg(errp, "missing tag property"); > > > + return; > > > + } > > > + len = strlen(fs->conf.tag); > > > + if (len == 0) { > > > + error_setg(errp, "tag property cannot be empty"); > > > + return; > > > + } > > > + if (len > sizeof_field(struct virtio_fs_config, tag)) { > > > + error_setg(errp, "tag property must be %zu bytes or less", > > > + sizeof_field(struct virtio_fs_config, tag)); > > > + return; > > > + } > > > + > > > + if (fs->conf.num_queues == 0) { > > > + error_setg(errp, "num-queues property must be larger than 0"); > > > + return; > > > + } > > > > The strange thing is that actual # of queues is this number + 2. > > And this affects an optimal number of vectors (see patch 2). > > Not sure what a good solution is - include the > > mandatory queues in the number? > > Needs to be documented in some way. > > I think the spec states that num_queues in the config space is the > number of request queues only. Can we rename to num_request_queues? The > hiprio queue is not really configurable, anyway. > > > > > > + > > > + if (!is_power_of_2(fs->conf.queue_size)) { > > > + error_setg(errp, "queue-size property must be a power of 2"); > > > + return; > > > + } > > > > Hmm packed ring allows non power of 2 ... > > We need to look into a generic helper to support VQ > > size checks. > > Huh, I didn't notice before that there are several devices which > already allow to configure the queue size... looking, there seem to be > the following cases: > > - bound checks and checks for power of 2 (blk, net) > - no checks (scsi) -- isn't that dangerous, as virtio_add_queue() will > abort() for a too large value? > > Anyway, if we have a non power of 2 size and the driver does not > negotiate packed, we can just fail setting FEATURES_OK, so dropping the > power of 2 check should be fine, at least when we add packed support. > > > > > > + > > > + if (fs->conf.queue_size > VIRTQUEUE_MAX_SIZE) { > > > + error_setg(errp, "queue-size property must be %u or smaller", > > > + VIRTQUEUE_MAX_SIZE); > > > + return; > > > + } > > > + > > > + if (!vhost_user_init(&fs->vhost_user, &fs->conf.chardev, errp)) { > > > + return; > > > + } > > > + > > > + virtio_init(vdev, "vhost-user-fs", VIRTIO_ID_FS, > > > + sizeof(struct virtio_fs_config)); > > > + > > > + /* Notifications queue */ > > > + virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output); > > > + > > > + /* Hiprio queue */ > > > + virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output); > > > > > > > Weird, spec patch v6 says: > > > > +\item[0] hiprio > > +\item[1\ldots n] request queues > > > > where's the Notifications queue coming from? > > Maybe an old name of the hiprio queue? > > > > > > + /* Request queues */ > > > + for (i = 0; i < fs->conf.num_queues; i++) { > > > + virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output); > > > + } > > > + > > > + /* 1 high prio queue, plus the number configured */ > > > + fs->vhost_dev.nvqs = 1 + fs->conf.num_queues; > > Anyway, the notifications queue needs to go, or this is wrong :) > > > > + fs->vhost_dev.vqs = g_new0(struct vhost_virtqueue, fs->vhost_dev.nvqs); > > > + ret = vhost_dev_init(&fs->vhost_dev, &fs->vhost_user, > > > + VHOST_BACKEND_TYPE_USER, 0); > > > + if (ret < 0) { > > > + error_setg_errno(errp, -ret, "vhost_dev_init failed"); > > > + goto err_virtio; > > > + } > > > + > > > + return; > > > + > > > +err_virtio: > > > + vhost_user_cleanup(&fs->vhost_user); > > > + virtio_cleanup(vdev); > > > + g_free(fs->vhost_dev.vqs); > > > + return; > > > +} > > (...) -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK