qemu/docs/pcie.txt

34 PCI Express devices should be plugged only into PCI Express Root Ports and
37 2.1 Root Bus (pcie.0)
39 Place only the following kinds of devices directly on the Root Complex:
42         the Root Complex. These will be considered Integrated Endpoints.
47         devices with the Root Complex. Guest OSes are suspected to behave
49         with the Root Complex.
51     (2) PCI Express Root Ports (pcie-root-port), for starting exclusively
57     (4) Extra Root Complexes (pxb-pcie), if multiple PCI Express Root Buses
64    | PCI Dev |   | PCIe Root Port |   | PCIe-PCI Bridge |   |  pxb-pcie  |
67 2.1.1 To plug a device into pcie.0 as a Root Complex Integrated Endpoint use:
69 2.1.2 To expose a new PCI Express Root Bus use:
71       PCI Express Root Ports and PCI Express to PCI bridges can be
73           -device pcie-root-port,id=root_port1[,bus=pcie.1][,chassis=x][,slot=y][,addr=z] \
79 Always use PCI Express Root Ports to start PCI Express hierarchies.
81 A PCI Express Root bus supports up to 32 devices. Since each
82 PCI Express Root Port is a function and a multi-function
84 number of PCI Express Root Ports per PCI Express Root Bus is 256.
86 Prefer grouping PCI Express Root Ports into multi-function devices
89 if there is no more room for PCI Express Root Ports.
99    | Root Port |    | Root Port |                        | Root Port |
114 2.2.1 Plugging a PCI Express device into a PCI Express Root Port:
115           -device pcie-root-port,id=root_port1,chassis=x,slot=y[,bus=pcie.0][,addr=z]  \
117 2.2.2 Using multi-function PCI Express Root Ports:
118 …   -device pcie-root-port,id=root_port1,multifunction=on,chassis=x,addr=z.0[,slot=y][,bus=pcie.0] \
119       -device pcie-root-port,id=root_port2,chassis=x1,addr=z.1[,slot=y1][,bus=pcie.0] \
120       -device pcie-root-port,id=root_port3,chassis=x2,addr=z.2[,slot=y2][,bus=pcie.0] \
122       -device pcie-root-port,id=root_port1,chassis=x,slot=y[,bus=pcie.0][,addr=z]  \
129     PCI Express Root Port. slot defaults to 0 when not specified.
173 The PCI Express Root Ports and PCI Express Downstream ports are seen by
180 by not allocating IO space for each PCI Express Root / PCI Express
187 10 PCI Express Root Ports or PCI Express Downstream Ports per system
199 machines do not support multiple PCI domains even if extra Root
202 Each element of the PCI Express hierarchy (Root Complexes,
203 PCI Express Root Ports, PCI Express Downstream/Upstream ports)
205 can be attached to a PCI Express Root Port or PCI Express Downstream
215 given pxb-pcie device's root bus must fit between the bus_nr property of
222 The PCI Express root buses (pcie.0 and the buses exposed by pxb-pcie devices)
223 do not support hot-plug, so any devices plugged into Root Complexes
226     (2) PCI Express Root Ports
239 PCI Express Root Ports (and PCI Express Downstream Ports).
255         Leave enough PCI Express Root Ports empty. Use multifunction
256         PCI Express Root Ports (up to 8 ports per pcie.0 slot)
257         on the Root Complex(es), for keeping the
261         that could be put to better use with another Root Port or Downstream
267 …device_add <dev>,id=<id>,bus=<PCI Express Root Port Id/PCI Express Downstream Port Id/PCI-PCI Brid…
273 PCI Express Root Ports or PCI Express Downstream Ports.
277   > lspci -s 03:00.0 -v (as root)