** Tags removed: targetmilestone-inin--- ** Tags added: targetmilestone-inin20045
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1961850 Title: [UBUNTU 20.04] s390/pci: move pseudo-MMIO to prevent MIO overlap Status in Ubuntu on IBM z Systems: Fix Released Status in linux package in Ubuntu: Fix Released Status in linux source package in Focal: Fix Released Status in linux source package in Impish: Fix Released Status in linux source package in Jammy: Fix Released Bug description: Description: s390/pci: move pseudo-MMIO to prevent MIO overlap Symptom: On some configurations of z15 LPARs having an ISM device attached may cause other PCI devices like NVMes or RoCEs to be unusable and fail to probe. An error message in the kernel log indicates that a PCI memory BAR could not be assigned. Problem: On z15 with the enhanced PCI memory I/O instructions (MIO) ISM devices still rely on the classic PCI instructions which used pseud-MMIO addresses created by Linux. These addresses can conflict with the firmware created MIO addresses which is detected by the Linux PCI resource allocation code which then prevents probing of the device even though technically the address conflict would not cause issues. Solution: Use disjunct ranges for Linux generated pseudo-MMIO and firmware provided MIO addresses. Reproduction: On an LPAR with a lot of PCI devices and in particular many ISM devices the conflict is more likely. It is however unclear how to provoke a conflict without special firmware. The fix was and will be tested on a known affected system. Upstream-ID: 52d04d408185b7aa47628d2339c28ec70074e0ae Distros: Ubuntu 20.04 and higher Preventive: yes Author: Niklas Schnelle <schne...@linux.ibm.com> Component: kernel To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1961850/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
