** Description changed: + [Impact] + Description: s390/pci: Fix PCHID per port multi-function detection Symptom: There are two cases in which PCI functions are incorrectly - placed, or not placed, in a shared PCI topology. In the first - case a PCI physical function (PF) which is initially in standby - was incorrectly not creating a new PCI topology when hotplugged, - but would if configured during boot. In the second case a PCI - virtual function (VF) would be placed in the shared PCI topology - of a PF if that PF is from the same card even if the parent PF - is not in the configuration which should lead the VF to be - isolated in its own single function topology. + placed, or not placed, in a shared PCI topology. In the first + case a PCI physical function (PF) which is initially in standby + was incorrectly not creating a new PCI topology when hotplugged, + but would if configured during boot. In the second case a PCI + virtual function (VF) would be placed in the shared PCI topology + of a PF if that PF is from the same card even if the parent PF + is not in the configuration which should lead the VF to be + isolated in its own single function topology. Problem: Both problems are caused by logic bugs in the determination of - which PCI functions create topologies and when a PCI function - may be added to an existing topology. + which PCI functions create topologies and when a PCI function + may be added to an existing topology. + + [Fix] + + Cherry pick from mainline of: + - dc287e4c9149 s390/pci: Fix SR-IOV for PFs initially in standby + - 05793884a1f3 s390/pci: Pull search for parent PF out of pci_iov_setup_virtfn() + - 2844ddbd540f s390/pci: Fix handling of isolated VFs + + [Test Plan] + + Fix tested by IBM. + + [Where problems could occur] + + The fix affects SR-IOV support in the s390x PCI subsystem. + A user might experience issues like missing or misconfigured VFs, failed VF passthrough to guests, sysfs inconsistencies, or degraded I/O performance.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2104120 Title: [Ubuntu 25.04] s390/pci: Fix PCHID per port multi-function detection To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/2104120/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
