[Virtio-fs] [Qemu-devel] [PATCH v2 1/2] virtio: add vhost-user-fs base device
Cornelia Huck
cohuck at redhat.com
Mon Aug 26 15:32:42 UTC 2019
On Fri, 23 Aug 2019 18:56:56 +0100
"Dr. David Alan Gilbert (git)" <dgilbert at redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert at redhat.com>
>
> 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 <stefanha at redhat.com>
> Signed-off-by: Sebastien Boeuf <sebastien.boeuf at intel.com>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert at redhat.com>
> ---
> 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..72e270d869
> --- /dev/null
> +++ b/hw/virtio/vhost-user-fs.c
> @@ -0,0 +1,297 @@
> +/*
> + * Vhost-user filesystem virtio device
> + *
> + * Copyright 2018 Red Hat, Inc.
Should that be 2018, 2019? (Also for vhost-user-fs.h.)
> + *
> + * Authors:
> + * Stefan Hajnoczi <stefanha at redhat.com>
> + *
> + * 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.
> + */
> +
(...)
> +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.
I still think referring to virtio-pci doing the right thing is not the
right thing here :) Can you spell out _what_ the right thing actually
is?
> + */
> + 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);
> +}
> +
(...)
> diff --git a/include/standard-headers/linux/virtio_fs.h b/include/standard-headers/linux/virtio_fs.h
> new file mode 100644
> index 0000000000..00bd7a6fa7
> --- /dev/null
> +++ b/include/standard-headers/linux/virtio_fs.h
This will probably be imported from the Linux source code, right? If
yes, this should go into a separate patch (and the headers update patch
probably needs an update.)
> @@ -0,0 +1,41 @@
> +#ifndef _LINUX_VIRTIO_FS_H
> +#define _LINUX_VIRTIO_FS_H
> +/* This header is BSD licensed so anyone can use the definitions to implement
> + * compatible drivers/servers.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + * notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + * notice, this list of conditions and the following disclaimer in the
> + * documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of IBM nor the names of its contributors
> + * may be used to endorse or promote products derived from this software
> + * without specific prior written permission.
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE. */
> +#include "standard-headers/linux/types.h"
> +#include "standard-headers/linux/virtio_ids.h"
> +#include "standard-headers/linux/virtio_config.h"
> +#include "standard-headers/linux/virtio_types.h"
> +
> +struct virtio_fs_config {
> + /* Filesystem name (UTF-8, not NUL-terminated, padded with NULs) */
> + uint8_t tag[36];
> +
> + /* Number of request queues */
> + uint32_t num_request_queues;
> +} QEMU_PACKED;
> +
> +#endif /* _LINUX_VIRTIO_FS_H */
> diff --git a/include/standard-headers/linux/virtio_ids.h b/include/standard-headers/linux/virtio_ids.h
> index 32b2f94d1f..73fc004807 100644
> --- a/include/standard-headers/linux/virtio_ids.h
> +++ b/include/standard-headers/linux/virtio_ids.h
This should also go into that separate patch.
> @@ -43,6 +43,7 @@
> #define VIRTIO_ID_INPUT 18 /* virtio input */
> #define VIRTIO_ID_VSOCK 19 /* virtio vsock transport */
> #define VIRTIO_ID_CRYPTO 20 /* virtio crypto */
> +#define VIRTIO_ID_FS 26 /* virtio filesystem */
> #define VIRTIO_ID_PMEM 27 /* virtio pmem */
>
> #endif /* _LINUX_VIRTIO_IDS_H */
Otherwise, looks good to me.
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