qemu/docs/pci_expander_bridge.txt

6 PXB is a "light-weight" host bridge in the same PCI domain
7 as the main host bridge whose purpose is to enable
8 the main host bridge to support multiple PCI root buses.
12 As opposed to PCI-2-PCI bridge's secondary bus, PXB's bus
14 (different from the main host bridge) allowing the guest OS
15 to recognize the proximity of a pass-through device to
22 [qemu-bin + storage options]
23 -m 2G
24 -object memory-backend-ram,size=1024M,policy=bind,host-nodes=0,id=ram-node0 -numa node,nodeid=0,cpu…
25 -object memory-backend-ram,size=1024M,policy=bind,host-nodes=1,id=ram-node1 -numa node,nodeid=1,cpu…
26 -device pxb,id=bridge1,bus=pci.0,numa_node=1,bus_nr=4 -netdev user,id=nd -device e1000,bus=bridge1,…
27 -device pxb,id=bridge2,bus=pci.0,numa_node=0,bus_nr=8 -device e1000,bus=bridge2,addr=0x3
28 -device pxb,id=bridge3,bus=pci.0,bus_nr=40 -drive if=none,id=drive0,file=[img] -device virtio-blk-p…
31 …- 2 NUMA nodes for the guest, 0 and 1. (both mapped to the same NUMA node in host, but you can and…
32  - a pxb host bridge attached to NUMA 1 with an e1000 behind it
33  - a pxb host bridge attached to NUMA 0 with an e1000 behind it
34  - a pxb host bridge not attached to any NUMA with a hard drive behind it.
45 - HostBridge (TYPE_PXB_HOST)
46   The host bridge allows to register and query the PXB's PCI root bus in QEMU.
47 - PXBDev(TYPE_PXB_DEVICE)
48 …It is a regular PCI Device that resides on the piix host-bridge bus and its bus uses the same PCI …
51   PCI-2-PCI bridge. The _PRT follows the i440fx model.
52 - PCIBridgeDev(TYPE_PCI_BRIDGE_DEV)
55   - Using the bridge will enable hotplug support
56   - All the devices behind the bridge will use bridge's IO/MEM windows compacting