** Description changed: - Description will follow + Today, the enumeration of PCI functions on s390x does not reflect which + functions belongs to which physical adapter. + + Layout of a PCI function address on Linux: + 0000:00:00.0 + <root complex>:<bus>:<device>.<function> + + On s390x, each function is presented as individual root complex today, + e.g.: + + PCHID 0100 VF1 0000:00:00.0 + PCHID 0100 VF23 0001:00:00.0 + PCHID 0200 VF1 0002:00:00.0 + OCHID 0100 VF17 0003:00:00.0 + + On other platforms, the addresses correctly reflect the actual HW + configuration. Some device drivers (mlx5 for Mellanox adapters) group + functions of one physical adapter by checking which PCI functions have + identical values for <root complex>:<bus>:<device>. We need to use the + same enumeration scheme to achieve this functionality on s390x. + + In this case, the two physical functions of a Mellanox adapter need to + get function number 0 and 1, and all virtual functions need to use the + same <root complex>:<bus> numbers with function/device numbers counting + up. + + Required result (example with 4 VFs per PF): + + PCHID 0100 PF 0 0000:00:00.0 + PCHID 0100 PF 1 0000:00:00.1 + PCHID 0100 PF 0 VF 0 0000:00:00.2 + PCHID 0100 PF 0 VF 1 0000:00:00.3 + PCHID 0100 PF 0 VF 2 0000:00:00.4 + PCHID 0100 PF 0 VF 3 0000:00:00.5 + PCHID 0100 PF 1 VF 0 0000:00:00.6 + PCHID 0100 PF 1 VF 1 0000:00:00.7 + PCHID 0100 PF 1 VF 2 0000:00:00.8 + PCHID 0100 PF 1 VF 3 0000:00:00.9 + + PCHID 0200 PF 0 0001:00:00.0
** Also affects: ubuntu-z-systems Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1874056 Title: [UBUNTU 20.04] s390x/pci: enumerate pci functions per physical adapter To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1874056/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs