Public bug reported: [ Impact ]
For Ubuntu 25.10 release we plan to raise the required RISC-V ISA profile family to RVA23. The ubuntu-release-upgrader should stop upgrades beyond Ubuntu 24.04 on hardware that does not support the RVA23U64 profile. RVA23U64 [1] is the profile relevant for user space. As there is no upgrade path from Ubuntu 25.04 Plucky for RVA20 systems, we should also stop upgrading these RISC-V systems from Noble to Plucky. The Linux kernel exposes available extensions via /proc/cpuinfo field ISA and via the hwprobe system call [3]. Which extensions are exposed depends on the kernel revision. We are backporting a v6.14 kernel to Ubuntu 24.04. We have to restrict our check to those RVA23 extensions exposed by this kernel release. As the ubuntu-release-upgrader is implemented in Python we should use /proc/cpuinfo for the extension detection. [1] RVA23 Profiles, Version 1.0, 2024-10-17 https://github.com/riscv/riscv-profiles/releases/download/rva23-rvb23-ratified/rva23-profile.pdf [2] RISC-V Linux User ABI https://docs.kernel.org/arch/riscv/uabi.html [3] RISC-V Hardware Probing Interface https://docs.kernel.org/arch/riscv/hwprobe.html [ Test Plan ] Test that Ubuntu 22.04 Jammy can be upgraded to Ubuntu 24.04 Noble on RVA20 hardware. Test that Ubuntu 24.04 Noble cannot be upgraded to Plucky or Questing on RVA20 hardware. Test that Ubuntu 25.04 Plucky cannot be upgraded to Questing on RVA20 hardware. Test that Ubuntu 24.04 Noble can be upgraded to Questing on a RVA23 virtual machine. Test that Ubuntu 24.04 Plucky can be upgraded to Questing on a RVA23 virtual machine. Test that Ubuntu 24.04 Plucky can be upgraded to Questing on an arm64 virtual machine. QEMU 10.0 provides all RVA23U64 extensions. [ Where problems could occur ] If incorrectly implemented, the upgrader might not correctly identify RVA20 and RVA23 systems and therefore might stop or allow upgrades in the wrong case. [ Other Info ] n/a ** Affects: ubuntu-release-upgrader (Ubuntu) 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/2111715 Title: On RISC-V check if hardware is RVA23 capapble To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/2111715/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
