This bug is awaiting verification that the linux-azure- fips/6.8.0-1042.48+fips1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-noble-linux-azure-fips' to 'verification-done-noble-linux-azure-fips'. If the problem still exists, change the tag 'verification-needed-noble-linux-azure-fips' to 'verification-failed-noble-linux-azure-fips'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: kernel-spammed-noble-linux-azure-fips-v2 verification-needed-noble-linux-azure-fips -- 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/2121146 Title: [UBUNTU 24.04] vfio/pci: fix 8-byte PCI loads and stores Status in Ubuntu on IBM z Systems: Fix Released Status in linux package in Ubuntu: Invalid Status in linux source package in Noble: Fix Released Bug description: [ Impact ] Reading from or writing to 64 bit registers (I/O ports or MMIO) on a PCI adapter attached via vfio with e.g. the pread()/pwrite() system calls may not work in case the PCI adapter requires a full read or write that can not be broken up. 64 bit reads/writes are not implemented via the vfio I/O port or MMIO access, even if the architecture supports 64 bit I/O reads and writes. It is necessary to implement the use of 64 bit I/O reads and writes in the vfio driver, so that such reads and writes are not broken up into multiple smaller operations if the architecture supports such bigger operations. [ Fix ] Backport the following commits in Noble: - 186bfe44ea41 vfio/pci: Extract duplicated code into macro - 4df13a6871d9 vfio/pci: Support 8-byte PCI loads and stores - abe8103da3c5 vfio/pci: Fix typo in macro to declare accessors [ Test Case ] Bind a PCI device to vfio-pci and open it via /dev/vfio/<group>. From user space, issue pread()/pwrite() calls with size 64-bit on the device’s registers. Use ftrace or similar tools to confirm vfio_pci_core_ioread64/vfio_pci_core_iowrite64 is invoked. If available, check that a device requiring atomic 64-bit access now works correctly. [ Regression Potential ] The fix affects how VFIO PCI handles 64-bit register accesses via pread() and pwrite() from user-space. A bug here could cause incorrect or partial reads and writes to device registers, breaking atomicity guarantees required by some PCI adapters. Users may see devices misconfiguration, inconsistent register values, unexpected hardware behavior, or even system instability when using user-space drivers with VFIO. --- Description: vfio/pci: fix 8-byte PCI loads and stores Symptom: Reading from or writing to 64 bit registers (I/O ports or MMIO) on a PCI adapter attached via vfio with e.g. the pread()/pwrite() system calls may not work in case the PCI adapter requires a full read or write that can not be broken up. Problem: 64 bit reads/writes are not implemented via the vfio I/O port or MMIO access, even if the architecture supports 64 bit I/O reads and writes. Solution: Implement the use of 64 bit I/O reads and writes in the vfio driver, so that such reads and writes are not broken up into multiple smaller operations if the architecture supports such bigger operations. Upstream-IDs: 186bfe44ea41fb38c7a69becd7078724d28cd03c 4df13a6871d9e97aeeef72244e9a954c5cf11f54 Component: kernel To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/2121146/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
