mirror of https://gitlab.com/qemu-project/qemu
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
27 lines
1008 B
ReStructuredText
27 lines
1008 B
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0-or-later
|
|
|
|
=========
|
|
vfio-user
|
|
=========
|
|
|
|
QEMU includes a ``vfio-user`` client. The ``vfio-user`` specification allows for
|
|
implementing (PCI) devices in userspace outside of QEMU; it is similar to
|
|
``vhost-user`` in this respect (see :doc:`vhost-user`), but can emulate arbitrary
|
|
PCI devices, not just ``virtio``. Whereas ``vfio`` is handled by the host
|
|
kernel, ``vfio-user``, while similar in implementation, is handled entirely in
|
|
userspace.
|
|
|
|
For example, SPDK includes a virtual PCI NVMe controller implementation; by
|
|
setting up a ``vfio-user`` UNIX socket between QEMU and SPDK, a VM can send NVMe
|
|
I/O to the SPDK process.
|
|
|
|
Presuming a suitable ``vfio-user`` server has opened a socket at
|
|
``/tmp/vfio-user.sock``, a device can be configured with for example:
|
|
|
|
.. code-block:: console
|
|
|
|
-device '{"driver": "vfio-user-pci","socket": {"path": "/tmp/vfio-user.sock", "type": "unix"}}'
|
|
|
|
See `libvfio-user <https://github.com/nutanix/libvfio-user/>`_ for further
|
|
information.
|