[Qemu-devel] [PATCH v2 0/2] Add virtio-fs (experimental)

[Qemu-devel] [PATCH v2 0/2] Add virtio-fs (experimental)

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Hi,
  This pair of patches adds the core of the virtio-fs support to qemu;
it's marked experimental since the kernel patch and spec changes aren't
in yet; but they're bubbling along.

  While the spec change is still in progress; the ID number is already
reserved.

  A future set of patches will add the optional DAX mapping support.

  The actual qemu change is pretty minimal, since it's really only
a virtio device with some queues.

Some links:
  Mailing list: https://www.redhat.com/mailman/listinfo/virtio-fs
  Dev tree: Including filesystem daemon: https://gitlab.com/virtio-fs/qemu
  kernel: https://gitlab.com/virtio-fs/linux
  virtio spec changes: https://lists.oasis-open.org/archives/virtio-dev/201908/msg00104.html

v2:
  Renamed num_queues to num_request_queues
  Add a not-reached assert to vuf_handle_output
  Kill the one bit of notification queue off
  Use the same trick as vhost-user-scsi to calculate the number
    of vectors for the PCI device

Dr. David Alan Gilbert (2):
  virtio: add vhost-user-fs base device
  virtio: add vhost-user-fs-pci device

 configure                                   |  13 +
 hw/virtio/Makefile.objs                     |   2 +
 hw/virtio/vhost-user-fs-pci.c               |  85 ++++++
 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 +
 7 files changed, 484 insertions(+)
 create mode 100644 hw/virtio/vhost-user-fs-pci.c
 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

-- 
2.21.0

[Qemu-devel] [PATCH v2 1/2] virtio: add vhost-user-fs base device

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@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@redhat.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@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/configure b/configure
index 0173db5d9f..d77996dd24 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
@@ -6422,6 +6431,7 @@ 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 $trace_file-<pid>"
@@ -6918,6 +6928,9 @@ fi
 if test "$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..72e270d869
--- /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 <stefanha@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.
+ */
+
+#include "qemu/osdep.h"
+#include <sys/ioctl.h>
+#include "standard-headers/linux/virtio_fs.h"
+#include "qapi/error.h"
+#include "hw/qdev-properties.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_request_queues, fs->conf.num_request_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 */
+    g_assert_not_reached();
+}
+
+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_request_queues == 0) {
+        error_setg(errp, "num-request-queues property must be larger than 0");
+        return;
+    }
+
+    if (!is_power_of_2(fs->conf.queue_size)) {
+        error_setg(errp, "queue-size property must be a power of 2");
+        return;
+    }
+
+    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));
+
+    /* Hiprio queue */
+    virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
+
+    /* Request queues */
+    for (i = 0; i < fs->conf.num_request_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_request_queues;
+    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;
+}
+
+static void vuf_device_unrealize(DeviceState *dev, Error **errp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserFS *fs = VHOST_USER_FS(dev);
+
+    /* This will stop vhost backend if appropriate. */
+    vuf_set_status(vdev, 0);
+
+    vhost_dev_cleanup(&fs->vhost_dev);
+
+    vhost_user_cleanup(&fs->vhost_user);
+
+    virtio_cleanup(vdev);
+    g_free(fs->vhost_dev.vqs);
+    fs->vhost_dev.vqs = NULL;
+}
+
+static const VMStateDescription vuf_vmstate = {
+    .name = "vhost-user-fs",
+    .unmigratable = 1,
+};
+
+static Property vuf_properties[] = {
+    DEFINE_PROP_CHR("chardev", VHostUserFS, conf.chardev),
+    DEFINE_PROP_STRING("tag", VHostUserFS, conf.tag),
+    DEFINE_PROP_UINT16("num-request-queues", VHostUserFS,
+                       conf.num_request_queues, 1),
+    DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128),
+    DEFINE_PROP_STRING("vhostfd", VHostUserFS, conf.vhostfd),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vuf_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+    dc->props = vuf_properties;
+    dc->vmsd = &vuf_vmstate;
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+    vdc->realize = vuf_device_realize;
+    vdc->unrealize = vuf_device_unrealize;
+    vdc->get_features = vuf_get_features;
+    vdc->get_config = vuf_get_config;
+    vdc->set_status = vuf_set_status;
+    vdc->guest_notifier_mask = vuf_guest_notifier_mask;
+    vdc->guest_notifier_pending = vuf_guest_notifier_pending;
+}
+
+static const TypeInfo vuf_info = {
+    .name = TYPE_VHOST_USER_FS,
+    .parent = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(VHostUserFS),
+    .class_init = vuf_class_init,
+};
+
+static void vuf_register_types(void)
+{
+    type_register_static(&vuf_info);
+}
+
+type_init(vuf_register_types)
diff --git a/include/hw/virtio/vhost-user-fs.h b/include/hw/virtio/vhost-user-fs.h
new file mode 100644
index 0000000000..7f1c8742b1
--- /dev/null
+++ b/include/hw/virtio/vhost-user-fs.h
@@ -0,0 +1,45 @@
+/*
+ * Vhost-user filesystem virtio device
+ *
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Authors:
+ *  Stefan Hajnoczi <stefanha@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.
+ */
+
+#ifndef _QEMU_VHOST_USER_FS_H
+#define _QEMU_VHOST_USER_FS_H
+
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-user.h"
+#include "chardev/char-fe.h"
+
+#define TYPE_VHOST_USER_FS "x-vhost-user-fs-device"
+#define VHOST_USER_FS(obj) \
+        OBJECT_CHECK(VHostUserFS, (obj), TYPE_VHOST_USER_FS)
+
+typedef struct {
+    CharBackend chardev;
+    char *tag;
+    uint16_t num_request_queues;
+    uint16_t queue_size;
+    char *vhostfd;
+} VHostUserFSConf;
+
+typedef struct {
+    /*< private >*/
+    VirtIODevice parent;
+    VHostUserFSConf conf;
+    struct vhost_virtqueue *vhost_vqs;
+    struct vhost_dev vhost_dev;
+    VhostUserState vhost_user;
+
+    /*< public >*/
+} VHostUserFS;
+
+#endif /* _QEMU_VHOST_USER_FS_H */
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
@@ -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
@@ -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 */
-- 
2.21.0

Re: [Qemu-devel] [PATCH v2 1/2] virtio: add vhost-user-fs base device

[Cornelia Huck]

On Fri, 23 Aug 2019 18:56:56 +0100
"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:

> From: "Dr. David Alan Gilbert" <dgilbert@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@redhat.com>
> Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@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@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.

Re: [Qemu-devel] [PATCH v2 1/2] virtio: add vhost-user-fs base device

[Dr. David Alan Gilbert]

* Cornelia Huck (cohuck@redhat.com) wrote:
> On Fri, 23 Aug 2019 18:56:56 +0100
> "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> 
> > From: "Dr. David Alan Gilbert" <dgilbert@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@redhat.com>
> > Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@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.)

Will fix.

> > + *
> > + * Authors:
> > + *  Stefan Hajnoczi <stefanha@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?

mst: Can you look at this?

This appears to be a chunk of code that's copied into many vhost files;
it's in at least vhost-user.c, vhost-user-blk.c, vhost-scsi-common.c and
vhost-vsock.c - it seemns to go back until at least 2013.

> > +     */
> > +    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.)

OK, will do.

> > @@ -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.

OK.

Dave

> > @@ -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.
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [Virtio-fs] [PATCH v2 1/2] virtio: add vhost-user-fs base device

[piaojun]

On 2019/8/24 1:56, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> The virtio-fs virtio device provides shared file system access using
> the FUSE protocol carried ovew virtio.

typo? ovew->over

> The actual file server is implemented in an external vhost-user-fs device
> backend process.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@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/configure b/configure
> index 0173db5d9f..d77996dd24 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
> @@ -6422,6 +6431,7 @@ 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 $trace_file-<pid>"
> @@ -6918,6 +6928,9 @@ fi
>  if test "$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..72e270d869
> --- /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 <stefanha@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.
> + */
> +
> +#include "qemu/osdep.h"
> +#include <sys/ioctl.h>
> +#include "standard-headers/linux/virtio_fs.h"
> +#include "qapi/error.h"
> +#include "hw/qdev-properties.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_request_queues, fs->conf.num_request_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 */
> +    g_assert_not_reached();
> +}
> +
> +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_request_queues == 0) {
> +        error_setg(errp, "num-request-queues property must be larger than 0");
> +        return;
> +    }
> +
> +    if (!is_power_of_2(fs->conf.queue_size)) {
> +        error_setg(errp, "queue-size property must be a power of 2");
> +        return;
> +    }
> +
> +    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));
> +
> +    /* Hiprio queue */
> +    virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
> +
> +    /* Request queues */
> +    for (i = 0; i < fs->conf.num_request_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_request_queues;
> +    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;
> +}
> +
> +static void vuf_device_unrealize(DeviceState *dev, Error **errp)
> +{
> +    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> +    VHostUserFS *fs = VHOST_USER_FS(dev);
> +
> +    /* This will stop vhost backend if appropriate. */
> +    vuf_set_status(vdev, 0);
> +
> +    vhost_dev_cleanup(&fs->vhost_dev);
> +
> +    vhost_user_cleanup(&fs->vhost_user);
> +
> +    virtio_cleanup(vdev);
> +    g_free(fs->vhost_dev.vqs);
> +    fs->vhost_dev.vqs = NULL;
> +}
> +
> +static const VMStateDescription vuf_vmstate = {
> +    .name = "vhost-user-fs",
> +    .unmigratable = 1,
> +};
> +
> +static Property vuf_properties[] = {
> +    DEFINE_PROP_CHR("chardev", VHostUserFS, conf.chardev),
> +    DEFINE_PROP_STRING("tag", VHostUserFS, conf.tag),
> +    DEFINE_PROP_UINT16("num-request-queues", VHostUserFS,
> +                       conf.num_request_queues, 1),
> +    DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128),
> +    DEFINE_PROP_STRING("vhostfd", VHostUserFS, conf.vhostfd),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vuf_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
> +
> +    dc->props = vuf_properties;
> +    dc->vmsd = &vuf_vmstate;
> +    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
> +    vdc->realize = vuf_device_realize;
> +    vdc->unrealize = vuf_device_unrealize;
> +    vdc->get_features = vuf_get_features;
> +    vdc->get_config = vuf_get_config;
> +    vdc->set_status = vuf_set_status;
> +    vdc->guest_notifier_mask = vuf_guest_notifier_mask;
> +    vdc->guest_notifier_pending = vuf_guest_notifier_pending;
> +}
> +
> +static const TypeInfo vuf_info = {
> +    .name = TYPE_VHOST_USER_FS,
> +    .parent = TYPE_VIRTIO_DEVICE,
> +    .instance_size = sizeof(VHostUserFS),
> +    .class_init = vuf_class_init,
> +};
> +
> +static void vuf_register_types(void)
> +{
> +    type_register_static(&vuf_info);
> +}
> +
> +type_init(vuf_register_types)
> diff --git a/include/hw/virtio/vhost-user-fs.h b/include/hw/virtio/vhost-user-fs.h
> new file mode 100644
> index 0000000000..7f1c8742b1
> --- /dev/null
> +++ b/include/hw/virtio/vhost-user-fs.h
> @@ -0,0 +1,45 @@
> +/*
> + * Vhost-user filesystem virtio device
> + *
> + * Copyright 2018 Red Hat, Inc.
> + *
> + * Authors:
> + *  Stefan Hajnoczi <stefanha@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.
> + */
> +
> +#ifndef _QEMU_VHOST_USER_FS_H
> +#define _QEMU_VHOST_USER_FS_H
> +
> +#include "hw/virtio/virtio.h"
> +#include "hw/virtio/vhost.h"
> +#include "hw/virtio/vhost-user.h"
> +#include "chardev/char-fe.h"
> +
> +#define TYPE_VHOST_USER_FS "x-vhost-user-fs-device"
> +#define VHOST_USER_FS(obj) \
> +        OBJECT_CHECK(VHostUserFS, (obj), TYPE_VHOST_USER_FS)
> +
> +typedef struct {
> +    CharBackend chardev;
> +    char *tag;
> +    uint16_t num_request_queues;
> +    uint16_t queue_size;
> +    char *vhostfd;
> +} VHostUserFSConf;
> +
> +typedef struct {
> +    /*< private >*/
> +    VirtIODevice parent;
> +    VHostUserFSConf conf;
> +    struct vhost_virtqueue *vhost_vqs;
> +    struct vhost_dev vhost_dev;
> +    VhostUserState vhost_user;
> +
> +    /*< public >*/
> +} VHostUserFS;
> +
> +#endif /* _QEMU_VHOST_USER_FS_H */
> 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
> @@ -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
> @@ -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 */
> 

Re: [Qemu-devel] [Virtio-fs] [PATCH v2 1/2] virtio: add vhost-user-fs base device

[Dr. David Alan Gilbert]

* piaojun (piaojun@huawei.com) wrote:
> 
> 
> On 2019/8/24 1:56, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > 
> > The virtio-fs virtio device provides shared file system access using
> > the FUSE protocol carried ovew virtio.
> 
> typo? ovew->over

oops; thanks!

Dave

> > The actual file server is implemented in an external vhost-user-fs device
> > backend process.
> > 
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@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/configure b/configure
> > index 0173db5d9f..d77996dd24 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
> > @@ -6422,6 +6431,7 @@ 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 $trace_file-<pid>"
> > @@ -6918,6 +6928,9 @@ fi
> >  if test "$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..72e270d869
> > --- /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 <stefanha@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.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include <sys/ioctl.h>
> > +#include "standard-headers/linux/virtio_fs.h"
> > +#include "qapi/error.h"
> > +#include "hw/qdev-properties.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_request_queues, fs->conf.num_request_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 */
> > +    g_assert_not_reached();
> > +}
> > +
> > +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_request_queues == 0) {
> > +        error_setg(errp, "num-request-queues property must be larger than 0");
> > +        return;
> > +    }
> > +
> > +    if (!is_power_of_2(fs->conf.queue_size)) {
> > +        error_setg(errp, "queue-size property must be a power of 2");
> > +        return;
> > +    }
> > +
> > +    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));
> > +
> > +    /* Hiprio queue */
> > +    virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
> > +
> > +    /* Request queues */
> > +    for (i = 0; i < fs->conf.num_request_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_request_queues;
> > +    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;
> > +}
> > +
> > +static void vuf_device_unrealize(DeviceState *dev, Error **errp)
> > +{
> > +    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > +    VHostUserFS *fs = VHOST_USER_FS(dev);
> > +
> > +    /* This will stop vhost backend if appropriate. */
> > +    vuf_set_status(vdev, 0);
> > +
> > +    vhost_dev_cleanup(&fs->vhost_dev);
> > +
> > +    vhost_user_cleanup(&fs->vhost_user);
> > +
> > +    virtio_cleanup(vdev);
> > +    g_free(fs->vhost_dev.vqs);
> > +    fs->vhost_dev.vqs = NULL;
> > +}
> > +
> > +static const VMStateDescription vuf_vmstate = {
> > +    .name = "vhost-user-fs",
> > +    .unmigratable = 1,
> > +};
> > +
> > +static Property vuf_properties[] = {
> > +    DEFINE_PROP_CHR("chardev", VHostUserFS, conf.chardev),
> > +    DEFINE_PROP_STRING("tag", VHostUserFS, conf.tag),
> > +    DEFINE_PROP_UINT16("num-request-queues", VHostUserFS,
> > +                       conf.num_request_queues, 1),
> > +    DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128),
> > +    DEFINE_PROP_STRING("vhostfd", VHostUserFS, conf.vhostfd),
> > +    DEFINE_PROP_END_OF_LIST(),
> > +};
> > +
> > +static void vuf_class_init(ObjectClass *klass, void *data)
> > +{
> > +    DeviceClass *dc = DEVICE_CLASS(klass);
> > +    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
> > +
> > +    dc->props = vuf_properties;
> > +    dc->vmsd = &vuf_vmstate;
> > +    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
> > +    vdc->realize = vuf_device_realize;
> > +    vdc->unrealize = vuf_device_unrealize;
> > +    vdc->get_features = vuf_get_features;
> > +    vdc->get_config = vuf_get_config;
> > +    vdc->set_status = vuf_set_status;
> > +    vdc->guest_notifier_mask = vuf_guest_notifier_mask;
> > +    vdc->guest_notifier_pending = vuf_guest_notifier_pending;
> > +}
> > +
> > +static const TypeInfo vuf_info = {
> > +    .name = TYPE_VHOST_USER_FS,
> > +    .parent = TYPE_VIRTIO_DEVICE,
> > +    .instance_size = sizeof(VHostUserFS),
> > +    .class_init = vuf_class_init,
> > +};
> > +
> > +static void vuf_register_types(void)
> > +{
> > +    type_register_static(&vuf_info);
> > +}
> > +
> > +type_init(vuf_register_types)
> > diff --git a/include/hw/virtio/vhost-user-fs.h b/include/hw/virtio/vhost-user-fs.h
> > new file mode 100644
> > index 0000000000..7f1c8742b1
> > --- /dev/null
> > +++ b/include/hw/virtio/vhost-user-fs.h
> > @@ -0,0 +1,45 @@
> > +/*
> > + * Vhost-user filesystem virtio device
> > + *
> > + * Copyright 2018 Red Hat, Inc.
> > + *
> > + * Authors:
> > + *  Stefan Hajnoczi <stefanha@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.
> > + */
> > +
> > +#ifndef _QEMU_VHOST_USER_FS_H
> > +#define _QEMU_VHOST_USER_FS_H
> > +
> > +#include "hw/virtio/virtio.h"
> > +#include "hw/virtio/vhost.h"
> > +#include "hw/virtio/vhost-user.h"
> > +#include "chardev/char-fe.h"
> > +
> > +#define TYPE_VHOST_USER_FS "x-vhost-user-fs-device"
> > +#define VHOST_USER_FS(obj) \
> > +        OBJECT_CHECK(VHostUserFS, (obj), TYPE_VHOST_USER_FS)
> > +
> > +typedef struct {
> > +    CharBackend chardev;
> > +    char *tag;
> > +    uint16_t num_request_queues;
> > +    uint16_t queue_size;
> > +    char *vhostfd;
> > +} VHostUserFSConf;
> > +
> > +typedef struct {
> > +    /*< private >*/
> > +    VirtIODevice parent;
> > +    VHostUserFSConf conf;
> > +    struct vhost_virtqueue *vhost_vqs;
> > +    struct vhost_dev vhost_dev;
> > +    VhostUserState vhost_user;
> > +
> > +    /*< public >*/
> > +} VHostUserFS;
> > +
> > +#endif /* _QEMU_VHOST_USER_FS_H */
> > 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
> > @@ -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
> > @@ -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 */
> > 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

[Qemu-devel] [PATCH v2 2/2] virtio: add vhost-user-fs-pci device

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Add the PCI version of vhost-user-fs.

Launch QEMU like this:

  qemu -chardev socket,path=/tmp/vhost-fs.sock,id=chr0
       -device x-vhost-user-fs-pci,tag=myfs,chardev=chr0

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/virtio/Makefile.objs       |  1 +
 hw/virtio/vhost-user-fs-pci.c | 85 +++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+)
 create mode 100644 hw/virtio/vhost-user-fs-pci.c

diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index 47ffbf22c4..e2f70fbb89 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -15,6 +15,7 @@ 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
+obj-$(call land,$(CONFIG_VHOST_USER_FS),$(CONFIG_VIRTIO_PCI)) += vhost-user-fs-pci.o
 obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock.o
 
 ifeq ($(CONFIG_VIRTIO_PCI),y)
diff --git a/hw/virtio/vhost-user-fs-pci.c b/hw/virtio/vhost-user-fs-pci.c
new file mode 100644
index 0000000000..0e70985094
--- /dev/null
+++ b/hw/virtio/vhost-user-fs-pci.c
@@ -0,0 +1,85 @@
+/*
+ * Vhost-user filesystem virtio device PCI glue
+ *
+ * Copyright 2018-2019 Red Hat, Inc.
+ *
+ * Authors:
+ *  Dr. David Alan Gilbert <dgilbert@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.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/vhost-user-fs.h"
+#include "virtio-pci.h"
+
+struct VHostUserFSPCI {
+    VirtIOPCIProxy parent_obj;
+    VHostUserFS vdev;
+};
+
+typedef struct VHostUserFSPCI VHostUserFSPCI;
+
+#define TYPE_VHOST_USER_FS_PCI "vhost-user-fs-pci-base"
+
+#define VHOST_USER_FS_PCI(obj) \
+        OBJECT_CHECK(VHostUserFSPCI, (obj), TYPE_VHOST_USER_FS_PCI)
+
+static Property vhost_user_fs_pci_properties[] = {
+    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
+                       DEV_NVECTORS_UNSPECIFIED),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_user_fs_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VHostUserFSPCI *dev = VHOST_USER_FS_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&dev->vdev);
+
+    if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
+        vpci_dev->nvectors = dev->vdev.conf.num_request_queues + 1;
+    }
+
+    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
+    object_property_set_bool(OBJECT(vdev), true, "realized", errp);
+}
+
+static void vhost_user_fs_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+    k->realize = vhost_user_fs_pci_realize;
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+    dc->props = vhost_user_fs_pci_properties;
+    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    pcidev_k->device_id = 0; /* Set by virtio-pci based on virtio id */
+    pcidev_k->revision = 0x00;
+    pcidev_k->class_id = PCI_CLASS_STORAGE_OTHER;
+}
+
+static void vhost_user_fs_pci_instance_init(Object *obj)
+{
+    VHostUserFSPCI *dev = VHOST_USER_FS_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_USER_FS);
+}
+
+static const VirtioPCIDeviceTypeInfo vhost_user_fs_pci_info = {
+    .base_name             = TYPE_VHOST_USER_FS_PCI,
+    .non_transitional_name = "x-vhost-user-fs-pci",
+    .instance_size = sizeof(VHostUserFSPCI),
+    .instance_init = vhost_user_fs_pci_instance_init,
+    .class_init    = vhost_user_fs_pci_class_init,
+};
+
+static void vhost_user_fs_pci_register(void)
+{
+    virtio_pci_types_register(&vhost_user_fs_pci_info);
+}
+
+type_init(vhost_user_fs_pci_register);
-- 
2.21.0

Re: [Qemu-devel] [PATCH v2 2/2] virtio: add vhost-user-fs-pci device

[Cornelia Huck]

On Fri, 23 Aug 2019 18:56:57 +0100
"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:

> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Add the PCI version of vhost-user-fs.
> 
> Launch QEMU like this:
> 
>   qemu -chardev socket,path=/tmp/vhost-fs.sock,id=chr0
>        -device x-vhost-user-fs-pci,tag=myfs,chardev=chr0
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>  hw/virtio/Makefile.objs       |  1 +
>  hw/virtio/vhost-user-fs-pci.c | 85 +++++++++++++++++++++++++++++++++++
>  2 files changed, 86 insertions(+)
>  create mode 100644 hw/virtio/vhost-user-fs-pci.c

Reviewed-by: Cornelia Huck <cohuck@redhat.com>

I still need to try and send out that patch wiring it up for ccw...

Re: [Qemu-devel] [PATCH v2 2/2] virtio: add vhost-user-fs-pci device

[Dr. David Alan Gilbert]

* Cornelia Huck (cohuck@redhat.com) wrote:
> On Fri, 23 Aug 2019 18:56:57 +0100
> "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> 
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > 
> > Add the PCI version of vhost-user-fs.
> > 
> > Launch QEMU like this:
> > 
> >   qemu -chardev socket,path=/tmp/vhost-fs.sock,id=chr0
> >        -device x-vhost-user-fs-pci,tag=myfs,chardev=chr0
> > 
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > ---
> >  hw/virtio/Makefile.objs       |  1 +
> >  hw/virtio/vhost-user-fs-pci.c | 85 +++++++++++++++++++++++++++++++++++
> >  2 files changed, 86 insertions(+)
> >  create mode 100644 hw/virtio/vhost-user-fs-pci.c
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 
> I still need to try and send out that patch wiring it up for ccw...

Thanks; the non-DAX version should be pretty simple.

Dave
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [Virtio-fs] [PATCH v2 0/2] Add virtio-fs (experimental)

[Dr. David Alan Gilbert]

Oops, ment to cc mst on this:

* Dr. David Alan Gilbert (git) (dgilbert@redhat.com) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Hi,
>   This pair of patches adds the core of the virtio-fs support to qemu;
> it's marked experimental since the kernel patch and spec changes aren't
> in yet; but they're bubbling along.
> 
>   While the spec change is still in progress; the ID number is already
> reserved.
> 
>   A future set of patches will add the optional DAX mapping support.
> 
>   The actual qemu change is pretty minimal, since it's really only
> a virtio device with some queues.
> 
> Some links:
>   Mailing list: https://www.redhat.com/mailman/listinfo/virtio-fs
>   Dev tree: Including filesystem daemon: https://gitlab.com/virtio-fs/qemu
>   kernel: https://gitlab.com/virtio-fs/linux
>   virtio spec changes: https://lists.oasis-open.org/archives/virtio-dev/201908/msg00104.html
> 
> v2:
>   Renamed num_queues to num_request_queues
>   Add a not-reached assert to vuf_handle_output
>   Kill the one bit of notification queue off
>   Use the same trick as vhost-user-scsi to calculate the number
>     of vectors for the PCI device
> 
> Dr. David Alan Gilbert (2):
>   virtio: add vhost-user-fs base device
>   virtio: add vhost-user-fs-pci device
> 
>  configure                                   |  13 +
>  hw/virtio/Makefile.objs                     |   2 +
>  hw/virtio/vhost-user-fs-pci.c               |  85 ++++++
>  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 +
>  7 files changed, 484 insertions(+)
>  create mode 100644 hw/virtio/vhost-user-fs-pci.c
>  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
> 
> -- 
> 2.21.0
> 
> _______________________________________________
> Virtio-fs mailing list
> Virtio-fs@redhat.com
> https://www.redhat.com/mailman/listinfo/virtio-fs
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK