NAME

       nbdkit-blkio-plugin - libblkio plugin for NVMe, vhost-user, vDPA, VFIO

SYNOPSIS

        nbdkit blkio [driver=]DRIVER [path=FILENAME] [num-queues=N] ...

DESCRIPTION

       nbdkit-blkio-plugin is an nbdkit(1) plugin for using libblkio to access various disk sources used for
       high performance applications and virtualization.  These include: NVMe, vhost-user, vDPA and VFIO.

       The first parameter after the plugin name should be the libblkio driver.  For example:

        nbdkit blkio virtio-blk-vhost-user path=vhost.sock
                 │              │               │
               plugin         driver       other parameters

   Driver: "nvme-io_uring"
        nbdkit blkio nvme-io_uring path=/dev/ng0n1

       Connect to an NVMe device, issuing commands through Linux io_uring (requires Linux ≥ 5.19).

   Driver: "virtio-blk-vfio-pci"
        nbdkit blkio virtio-blk-vfio-pci path=/sys/bus/pci/devices/0000:00:01.0

       Connect to a PCI device which implements virtio-blk using VFIO.  The path is the path to the device's
       sysfs directory (see lspci(8)).

   Driver: "virtio-blk-vhost-user"
        nbdkit blkio virtio-blk-vhost-user path=vhost.sock

       Connect to a vhost-user block device, such as one exported by qemu-storage-daemon(1).  The path is the
       vhost-user Unix domain socket.  For example:

        qemu-storage-daemon \
           --blockdev driver=file,node-name=file,filename=disk.qcow2 \
           --blockdev driver=qcow2,node-name=qcow2,file=file \
           --export type=vhost-user-blk,id=export,addr.type=unix,addr.path=vhost.sock,node-name=qcow2,writable=on

   Driver: "virtio-blk-vhost-vdpa"
        nbdkit blkio virtio-blk-vhost-vdpa path=chardev

       Connect to a vDPA device which might be implemented in software (eg. VDUSE) or hardware.  The path is the
       vhost-vdpa character device.

   Driver: "io_uring"
        nbdkit blkio io_uring path=FILENAME

       You can use this driver to access local files and block devices through the libblkio "io_uring" driver,
       but it is usually faster and easier to use nbdkit-file-plugin(1).

PARAMETERS

       [driver=]DRIVER
           The name of the libblkio driver to use.

           This parameter is required.

           "driver="  is  a  magic  config  key  and  may  be  omitted in most cases.  See "Magic parameters" in
           nbdkit(1).

       PROPERTY=VALUE
           Properties such as "path", "num-entries" etc are translated  to  libblkio  properties.   Consult  the
           libblkio documentation for a complete list.

       get=PROPERTY
           Get  (print) the value of a property after connecting.  The property is fetched and printed in nbdkit
           debug output, so you will need to use the --verbose flag.  This is useful for debugging.

FILES

       $plugindir/nbdkit-blkio-plugin.so
           The plugin.

           Use "nbdkit --dump-config" to find the location of $plugindir.

VERSION

       "nbdkit-blkio-plugin" first appeared in nbdkit 1.34.

SEE ALSO

       nbdkit-file-plugin(1),     lspci(8),     qemu-storage-daemon(1),     https://libblkio.gitlab.io/libblkio,
       https://libblkio.gitlab.io/libblkio/blkio.html.

AUTHORS

       Richard W.M. Jones

COPYRIGHT

       Copyright Red Hat

LICENSE

       Redistribution  and  use in source and binary forms, with or without modification, are permitted provided
       that the following conditions are met:

       •   Redistributions of source code must retain the above copyright notice, this list  of  conditions  and
           the following disclaimer.

       •   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.

       •   Neither  the  name  of  Red  Hat  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 RED HAT 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 RED HAT 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.

nbdkit-1.42.2                                      2025-04-02                             nbdkit-blkio-plugin(1)