3 files changed, 94 insertions, 11 deletions
diff --git a/docs/system/devices/cxl.rst b/docs/system/devices/cxl.rst
index 882b036..ca15a0d 100644
--- a/docs/system/devices/cxl.rst
+++ b/docs/system/devices/cxl.rst
@@ -308,7 +308,7 @@ A very simple setup with just one directly attached CXL Type 3 Persistent Memory
   -object memory-backend-file,id=cxl-lsa1,share=on,mem-path=/tmp/lsa.raw,size=256M \
   -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \
   -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \
-  -device cxl-type3,bus=root_port13,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0 \
+  -device cxl-type3,bus=root_port13,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0,sn=0x1 \
   -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G
 
 A very simple setup with just one directly attached CXL Type 3 Volatile Memory device::
@@ -349,13 +349,13 @@ the CXL Type3 device directly attached (no switches).::
   -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \
   -device pxb-cxl,bus_nr=222,bus=pcie.0,id=cxl.2 \
   -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \
-  -device cxl-type3,bus=root_port13,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0 \
+  -device cxl-type3,bus=root_port13,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0,sn=0x1 \
   -device cxl-rp,port=1,bus=cxl.1,id=root_port14,chassis=0,slot=3 \
-  -device cxl-type3,bus=root_port14,persistent-memdev=cxl-mem2,lsa=cxl-lsa2,id=cxl-pmem1 \
+  -device cxl-type3,bus=root_port14,persistent-memdev=cxl-mem2,lsa=cxl-lsa2,id=cxl-pmem1,sn=0x2 \
   -device cxl-rp,port=0,bus=cxl.2,id=root_port15,chassis=0,slot=5 \
-  -device cxl-type3,bus=root_port15,persistent-memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem2 \
+  -device cxl-type3,bus=root_port15,persistent-memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem2,sn=0x3 \
   -device cxl-rp,port=1,bus=cxl.2,id=root_port16,chassis=0,slot=6 \
-  -device cxl-type3,bus=root_port16,persistent-memdev=cxl-mem4,lsa=cxl-lsa4,id=cxl-pmem3 \
+  -device cxl-type3,bus=root_port16,persistent-memdev=cxl-mem4,lsa=cxl-lsa4,id=cxl-pmem3,sn=0x4 \
   -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.targets.1=cxl.2,cxl-fmw.0.size=4G,cxl-fmw.0.interleave-granularity=8k
 
 An example of 4 devices below a switch suitable for 1, 2 or 4 way interleave::
@@ -375,15 +375,26 @@ An example of 4 devices below a switch suitable for 1, 2 or 4 way interleave::
   -device cxl-rp,port=1,bus=cxl.1,id=root_port1,chassis=0,slot=1 \
   -device cxl-upstream,bus=root_port0,id=us0 \
   -device cxl-downstream,port=0,bus=us0,id=swport0,chassis=0,slot=4 \
-  -device cxl-type3,bus=swport0,persistent-memdev=cxl-mem0,lsa=cxl-lsa0,id=cxl-pmem0 \
+  -device cxl-type3,bus=swport0,persistent-memdev=cxl-mem0,lsa=cxl-lsa0,id=cxl-pmem0,sn=0x1 \
   -device cxl-downstream,port=1,bus=us0,id=swport1,chassis=0,slot=5 \
-  -device cxl-type3,bus=swport1,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem1 \
+  -device cxl-type3,bus=swport1,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem1,sn=0x2 \
   -device cxl-downstream,port=2,bus=us0,id=swport2,chassis=0,slot=6 \
-  -device cxl-type3,bus=swport2,persistent-memdev=cxl-mem2,lsa=cxl-lsa2,id=cxl-pmem2 \
+  -device cxl-type3,bus=swport2,persistent-memdev=cxl-mem2,lsa=cxl-lsa2,id=cxl-pmem2,sn=0x3 \
   -device cxl-downstream,port=3,bus=us0,id=swport3,chassis=0,slot=7 \
-  -device cxl-type3,bus=swport3,persistent-memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem3 \
+  -device cxl-type3,bus=swport3,persistent-memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem3,sn=0x4 \
   -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G,cxl-fmw.0.interleave-granularity=4k
 
+A simple arm/virt example featuring a single direct connected CXL Type 3
+Volatile Memory device::
+
+  qemu-system-aarch64 -M virt,gic-version=3,cxl=on -m 4g,maxmem=8g,slots=4 -cpu max -smp 4 \
+  ...
+  -object memory-backend-ram,id=vmem0,share=on,size=256M \
+  -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \
+  -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \
+  -device cxl-type3,bus=root_port13,volatile-memdev=vmem0,id=cxl-vmem0 \
+  -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G
+
 Deprecations
 ------------
 
diff --git a/docs/system/devices/net.rst b/docs/system/devices/net.rst
index a3efbdc..4d787c3 100644
--- a/docs/system/devices/net.rst
+++ b/docs/system/devices/net.rst
@@ -85,13 +85,59 @@ passt doesn't require any capability or privilege. passt has
 better performance than ``-net user``, full IPv6 support and better security
 as it's a daemon that is not executed in QEMU context.
 
-passt can be connected to QEMU either by using a socket
-(``-netdev stream``) or using the vhost-user interface (``-netdev vhost-user``).
+passt_ can be used in the same way as the user backend (using ``-net passt``,
+``-netdev passt`` or ``-nic passt``) or it can be launched manually and
+connected to QEMU either by using a socket (``-netdev stream``) or by using
+the vhost-user interface (``-netdev vhost-user``).
+
+Using ``-netdev stream`` or ``-netdev vhost-user`` will allow the user to
+enable functionalities not available through the passt backend interface
+(like migration).
+
 See `passt(1)`_ for more details on passt.
 
 .. _passt: https://passt.top/
 .. _passt(1): https://passt.top/builds/latest/web/passt.1.html
 
+To use the passt backend interface
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+There is no need to start the daemon as QEMU will do it for you.
+
+By default, passt will be started in the socket-based mode.
+
+.. parsed-literal::
+   |qemu_system| [...OPTIONS...] -nic passt
+
+   (qemu) info network
+   e1000e.0: index=0,type=nic,model=e1000e,macaddr=52:54:00:12:34:56
+    \ #net071: index=0,type=passt,stream,connected to pid 24846
+
+.. parsed-literal::
+   |qemu_system| [...OPTIONS...] -net nic -net passt,tcp-ports=10001,udp-ports=10001
+
+   (qemu) info network
+   hub 0
+    \ hub0port1: #net136: index=0,type=passt,stream,connected to pid 25204
+    \ hub0port0: e1000e.0: index=0,type=nic,model=e1000e,macaddr=52:54:00:12:34:56
+
+.. parsed-literal::
+   |qemu_system| [...OPTIONS...] -netdev passt,id=netdev0 -device virtio-net,mac=9a:2b:2c:2d:2e:2f,id=virtio0,netdev=netdev0
+
+   (qemu) info network
+   virtio0: index=0,type=nic,model=virtio-net-pci,macaddr=9a:2b:2c:2d:2e:2f
+    \ netdev0: index=0,type=passt,stream,connected to pid 25428
+
+To use the vhost-based interface, add the ``vhost-user=on`` parameter and
+select the virtio-net device:
+
+.. parsed-literal::
+   |qemu_system| [...OPTIONS...] -nic passt,model=virtio,vhost-user=on
+
+   (qemu) info network
+   virtio-net-pci.0: index=0,type=nic,model=virtio-net-pci,macaddr=52:54:00:12:34:56
+    \ #net006: index=0,type=passt,vhost-user,connected to pid 25731
+
 To use socket based passt interface:
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/docs/system/devices/vfio-user.rst b/docs/system/devices/vfio-user.rst
new file mode 100644
index 0000000..b6dcaa5
--- /dev/null
+++ b/docs/system/devices/vfio-user.rst
@@ -0,0 +1,26 @@
+.. 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.