[libvirt-users] pcie-expander-bus doesn't support pcie-pci-bridge and pcie-switch-upstream-port

In libvirt, I found pcie-expander-bus controller doesn't support pcie-to-pci-bridge and pcie-switch-upstream-port. Version: libvirt-4.9 # cat /tmp/c.xml ... <controller type='pci' index='0' model='pcie-root'/> <controller type='pci' index='1' model='pcie-expander-bus'> <model name='pxb-pcie'/> <target busNr='3'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </controller> <controller type='pci' index='2' model='pcie-to-pci-bridge'> <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/> </controller> ... # virsh -k0 -K0 define /tmp/c.xml error: Failed to define domain from /tmp/c.xml error: XML error: The device at PCI address 0000:01:00.0 cannot be plugged into the PCI controller with index='1'. It requires a controller that accepts a pcie-to-pci-bridge. # cat /tmp/b.xml ... <controller type='pci' index='0' model='pcie-root'/> <controller type='pci' index='1' model='pcie-expander-bus'> <model name='pxb-pcie'/> <target busNr='3'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </controller> <controller type='pci' index='2' model='pcie-switch-upstream-port'> <model name='x3130-upstream'/> <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/> </controller> ... # virsh -k0 -K0 define /tmp/b.xml error: Failed to define domain from /tmp/b.xml error: XML error: The device at PCI address 0000:01:00.0 cannot be plugged into the PCI controller with index='1'. It requires a controller that accepts a pci-switch-upstream-port. In function virDomainPCIAddressBusSetModel, I find pcie-expander-bus only supports pcie-root-port and dmi-to-pci-bridge 353 case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_EXPANDER_BUS: 354 ┆ /* 32 slots, no hotplug, only accepts pcie-root-port or 355 ┆ ┆* dmi-to-pci-bridge 356 ┆ ┆*/ 357 ┆ bus->flags = (VIR_PCI_CONNECT_TYPE_PCIE_ROOT_PORT | 358 ┆ ┆ ┆ ┆ ┆ VIR_PCI_CONNECT_TYPE_DMI_TO_PCI_BRIDGE); 359 ┆ bus->minSlot = 0; 360 ┆ bus->maxSlot = VIR_PCI_ADDRESS_SLOT_LAST; 361 ┆ break; But it works in qemu: # /usr/libexec/qemu-kvm -machine q35 -m 1024 -device pxb-pcie,bus_nr=250,id=pci.1,bus=pcie.0,addr=0x4 -device pcie-pci-bridge,id=pci.250,bus=pci.1,addr=0x0 -device pcie-pci-bridge,id=pci.251,bus=pci.1,addr=0x1 -spice port=5902,addr=0.0.0.0,disable-ticketing /var/lib/libvirt/images/q35.qcow2 So why pcie-expander-bus doesn't these two controllers? For any concerns in libvirt? Thank you~ -- Best regards, ----------------------------------- Han Han Quality Engineer Redhat. Email: hhan(a)redhat.com Phone: +861065339333