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 028D3C3A59E for ; Wed, 21 Aug 2019 19:12:17 +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 B8EED216F4 for ; Wed, 21 Aug 2019 19:12:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8EED216F4 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]:53878 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0W1n-0003m2-Vl for qemu-devel@archiver.kernel.org; Wed, 21 Aug 2019 15:12:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51596) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0W14-0003A8-DF for qemu-devel@nongnu.org; Wed, 21 Aug 2019 15:11:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i0W12-0004pf-4Y for qemu-devel@nongnu.org; Wed, 21 Aug 2019 15:11:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48686) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i0W11-0004pE-Rj for qemu-devel@nongnu.org; Wed, 21 Aug 2019 15:11:28 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 206EB300177F for ; Wed, 21 Aug 2019 19:11:27 +0000 (UTC) Received: from work-vm (ovpn-117-245.ams2.redhat.com [10.36.117.245]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 38F1E5D9D3; Wed, 21 Aug 2019 19:11:20 +0000 (UTC) Date: Wed, 21 Aug 2019 20:11:18 +0100 From: "Dr. David Alan Gilbert" To: "Michael S. Tsirkin" Message-ID: <20190821191118.GN3309@work-vm> References: <20190816143321.20903-1-dgilbert@redhat.com> <20190816143321.20903-2-dgilbert@redhat.com> <20190818065944-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190818065944-mutt-send-email-mst@kernel.org> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Wed, 21 Aug 2019 19:11:27 +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: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Michael S. Tsirkin (mst@redhat.com) 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/configure b/configure > > index 714e7fb6a1..e7e33ee783 100755 > > --- a/configure > > +++ b/configure > > @@ -382,6 +382,7 @@ vhost_crypto="" > > vhost_scsi="" > > vhost_vsock="" > > vhost_user="" > > +vhost_user_fs="" > > kvm="no" > > hax="no" > > hvf="no" > > @@ -1316,6 +1317,10 @@ for opt do > > ;; > > --enable-vhost-vsock) vhost_vsock="yes" > > ;; > > + --disable-vhost-user-fs) vhost_user_fs="no" > > + ;; > > + --enable-vhost-user-fs) vhost_user_fs="yes" > > + ;; > > --disable-opengl) opengl="no" > > ;; > > --enable-opengl) opengl="yes" > > @@ -2269,6 +2274,10 @@ test "$vhost_crypto" = "" && vhost_crypto=$vhost_user > > if test "$vhost_crypto" = "yes" && test "$vhost_user" = "no"; then > > error_exit "--enable-vhost-crypto requires --enable-vhost-user" > > fi > > +test "$vhost_user_fs" = "" && vhost_user_fs=$vhost_user > > +if test "$vhost_user_fs" = "yes" && test "$vhost_user" = "no"; then > > + error_exit "--enable-vhost-user-fs requires --enable-vhost-user" > > +fi > > > > # OR the vhost-kernel and vhost-user values for simplicity > > if test "$vhost_net" = ""; then > > @@ -6425,6 +6434,7 @@ echo "vhost-crypto support $vhost_crypto" > > echo "vhost-scsi support $vhost_scsi" > > echo "vhost-vsock support $vhost_vsock" > > echo "vhost-user support $vhost_user" > > +echo "vhost-user-fs support $vhost_user_fs" > > echo "Trace backends $trace_backends" > > if have_backend "simple"; then > > echo "Trace output file $trace_file-" > > @@ -6921,6 +6931,9 @@ fi > > if test "$vhost_user" = "yes" ; then > > echo "CONFIG_VHOST_USER=y" >> $config_host_mak > > fi > > +if test "$vhost_user_fs" = "yes" ; then > > + echo "CONFIG_VHOST_USER_FS=y" >> $config_host_mak > > +fi > > if test "$blobs" = "yes" ; then > > echo "INSTALL_BLOBS=yes" >> $config_host_mak > > fi > > diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs > > index 964ce78607..47ffbf22c4 100644 > > --- a/hw/virtio/Makefile.objs > > +++ b/hw/virtio/Makefile.objs > > @@ -11,6 +11,7 @@ common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o > > common-obj-$(CONFIG_VIRTIO_MMIO) += virtio-mmio.o > > obj-$(CONFIG_VIRTIO_BALLOON) += virtio-balloon.o > > obj-$(CONFIG_VIRTIO_CRYPTO) += virtio-crypto.o > > +obj-$(CONFIG_VHOST_USER_FS) += vhost-user-fs.o > > obj-$(call land,$(CONFIG_VIRTIO_CRYPTO),$(CONFIG_VIRTIO_PCI)) += virtio-crypto-pci.o > > obj-$(CONFIG_VIRTIO_PMEM) += virtio-pmem.o > > common-obj-$(call land,$(CONFIG_VIRTIO_PMEM),$(CONFIG_VIRTIO_PCI)) += virtio-pmem-pci.o > > 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" > > + > > +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. > > + */ > > + 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_stop(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; > > + > > + if (!k->set_guest_notifiers) { > > + return; > > + } > > + > > + vhost_dev_stop(&fs->vhost_dev, vdev); > > + > > + ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false); > > + if (ret < 0) { > > + error_report("vhost guest notifier cleanup failed: %d", ret); > > + return; > > + } > > + > > + vhost_dev_disable_notifiers(&fs->vhost_dev, vdev); > > +} > > + > > +static void vuf_set_status(VirtIODevice *vdev, uint8_t status) > > +{ > > + VHostUserFS *fs = VHOST_USER_FS(vdev); > > + bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK; > > + > > + if (!vdev->vm_running) { > > + should_start = false; > > + } > > + > > + if (fs->vhost_dev.started == should_start) { > > + return; > > + } > > + > > + if (should_start) { > > + vuf_start(vdev); > > + } else { > > + vuf_stop(vdev); > > + } > > +} > > + > > +static uint64_t vuf_get_features(VirtIODevice *vdev, > > + uint64_t requested_features, > > + Error **errp) > > +{ > > + /* No feature bits used yet */ > > + return requested_features; > > +} > > + > > +static void vuf_handle_output(VirtIODevice *vdev, VirtQueue *vq) > > +{ > > + /* Do nothing */ > > Why is this safe? Is this because this never triggers? assert(0) then? > If it triggers then backend won't be notified, which might > cause it to get stuck. We never process these queues in qemu - always in the guest; so am I correct in thinking those shouldn't be used? > > +} > > + > > +static void vuf_guest_notifier_mask(VirtIODevice *vdev, int idx, > > + bool mask) > > +{ > > + VHostUserFS *fs = VHOST_USER_FS(vdev); > > + > > + vhost_virtqueue_mask(&fs->vhost_dev, vdev, idx, mask); > > +} > > + > > +static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx) > > +{ > > + VHostUserFS *fs = VHOST_USER_FS(vdev); > > + > > + return vhost_virtqueue_pending(&fs->vhost_dev, idx); > > +} > > + > > +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. Should we be doing nvectors the same way virtio-scsi-pci does it; with a magic 'unspecified' default where it sets the nvectors based on the number of queues? I think my preference is not to show the users the mandatory queues. > > + > > + 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. Which would also have to include the negotiation of where it's doing packaged ring? Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK