When building the PCI topology of a domain that has PCI devices with no assigned PCI addresses, the function virDomainPCIAddressSetGrow() will attempt to add a new PCI controller with the appropriate type of slot to connect a device that doesn't have a PCI address. In some cases this isn't possible (for example, if the device you are attempting to add to the topology requires a type of connection only provided by some controller that *itself* requires a connection of a type not available for the given architecture/machinetype, e.g. if you want to add a pcie-root-port to a domain with a machine type that has a pci-root (no PCIE)). In those cases, an error message is logged by using virDomainPCIControllerConectTypeToModel() to extract the type of device from the "flags" that are sent to virDomainPCIAddressSetGrow(). However, if virDomainPCIControllerConectTypeToModel() doesn't find a device type in the connection flags, it will return -1, and virDomainPCIAddressSetGrow() will log the very generic: Cannot automatically add a new PCI bus for a device with connect flags nnnn Both of these functions were written prior to libvirt adding support for the pcie-to-pci-bridge controller, and when that support was added (in 2018), a new if() clause wasn't added to virDomainPCIControllerConectTypeToModel(). Seven (!) years later, this omission was noticed by someone adding a new test case to regression testing. This patches remedies the earlier omission, so that now when someone tries to add a pcie-to-pci-bridge controller to a domain that doesn't have PCIE, the message will be: a PCI slot is needed to connect a PCI controller model='pcie-to-pci-bridge', but none is available, and it cannot be automatically added This is still not an ideal error message, but is arguably better. (NB: Unfortunately it isn't possible to use a switch() statement with no default case (in order to catch a similar error in the future), since we are converting from bitmapped flags. Fortunately, we haven't needed to add a new PCI controller type in the last 7 1/2 years :-) Resolves: https://issues.redhat.com/browse/RHEL-62032 Fixes: 542f05e7756cc5614eb2ee7b0bac9aabb7aa016c Signed-off-by: Laine Stump <laine@redhat.com> --- src/conf/domain_addr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/conf/domain_addr.c b/src/conf/domain_addr.c index 8dfa8feca0..7d58e2222a 100644 --- a/src/conf/domain_addr.c +++ b/src/conf/domain_addr.c @@ -286,6 +286,9 @@ virDomainPCIControllerConnectTypeToModel(virDomainPCIConnectFlags flags) if (flags & VIR_PCI_CONNECT_TYPE_PCI_BRIDGE) return VIR_DOMAIN_CONTROLLER_MODEL_PCI_BRIDGE; + if (flags & VIR_PCI_CONNECT_TYPE_PCIE_TO_PCI_BRIDGE) + return VIR_DOMAIN_CONTROLLER_MODEL_PCIE_TO_PCI_BRIDGE; + /* some connect types don't correspond to a controller model */ return -1; } -- 2.51.0