** Description changed: SRU Justification: ================== [Impact] - * The SIGP processing on KVM/s390x is incorrect and not fully conformant to - the 'Principles of Operations', the IBM Z architecture definition - and documentation. + * The SIGP processing on KVM/s390x is incorrect and not fully conform to + the 'Principles of Operations', the IBM Z architecture definition + and documentation. * KVM: SIGP RESTART is reporting a CPU state 'stopped' after SIGP RESTART - was issued, while it should report a 'busy' condition until the CPU is - really started. + was issued, while it should report a 'busy' condition until the CPU is + really started. * The fix for this consists of three patches: - 812de04661c4 "KVM: s390: Clarify SIGP orders versus STOP/RESTART" - 435d17955519 "KVM: s390: Add a routine for setting userspace CPU state" - 4563bcad46bf "KVM: s390: Simplify SIGP Set Arch handling" - whereas 812de04661c4 already landed via upstream stable, - hence only two are left and need to be cherry-picked: + 812de04661c4 "KVM: s390: Clarify SIGP orders versus STOP/RESTART" + 435d17955519 "KVM: s390: Add a routine for setting userspace CPU state" + 4563bcad46bf "KVM: s390: Simplify SIGP Set Arch handling" + whereas 812de04661c4 already landed via upstream stable, + hence only two are left and need to be cherry-picked: [Fix] * 67cf68b6a5ccac8bc7dfef0a220b59af4c83fd2c 67cf68b6a5cc "KVM: s390: Add a routine for setting userspace CPU state" * 8eeba194a32e0f50329354a696baaa2e3d9accc5 8eeba194a32e "KVM: s390: Simplify SIGP Set Arch handling" [Test Case] * Install an LPAR on IBM Z (z13+) or LinuxONE (Emperor / Rockhopper) - with Ubuntu Server 20.04 using kernel standard kernel 5.4. + with Ubuntu Server 20.04 using kernel standard kernel 5.4. * Setup this LPAR as QEMU/KVM host and a focal VM as guest. * The test itself is the following unit test: - https://lore.kernel.org/r/20220303210425.1693486-1-far...@linux.ibm.com/ + https://lore.kernel.org/r/20220303210425.1693486-1-far...@linux.ibm.com/ * The test and verification will be done by the IBM Z team. [Where problems could occur] - <this is pretty high level and generic, anything more specific to add?> - * A broken patch could harm KVM ioctl on s390x or the (virtual) CPU - state control in general. + state control in general. * The SIGP handing (on s390x) can become broken, which could lead to - incorrect (virtual) CPU states. + incorrect (virtual) CPU states. * In worst case KVM can become broken on s390x entirely. * The modified code is all s390x specific QEMU/KVM code, - no common code is touched. + no common code is touched. [Other] * The two remaining patches are upstream since 5.16, - the first one already landed in 5.4 via upstream stable bug LP#1959701 - and in 5.13 via upstream stable bug LP#1960861. + the first one already landed in 5.4 via upstream stable bug LP#1959701 + and in 5.13 via upstream stable bug LP#1960861. * The patches already landed in jammy (master-next) based on LP#1959735, - hence only SRU to impish and focal is needed. + hence only SRU to impish and focal is needed. * This patches got discussed here: - https://lore.kernel.org/all/20211008203112.1979843-2-far...@linux.ibm.com/ + https://lore.kernel.org/all/20211008203112.1979843-2-far...@linux.ibm.com/ * This not only fixes the SIGP processing, but is also important in terms of - long term maintainability. + long term maintainability. __________ Description: KVM: SIGP RESTART is reporting a CPU state 'stopped' after SIGP RESTART was issued, while it should report a 'busy' condition until the CPU is really started. The patches to fix this have already been picked for jammy/master-next: 812de04661c4 "KVM: s390: Clarify SIGP orders versus STOP/RESTART" 435d17955519 "KVM: s390: Add a routine for setting userspace CPU state" 4563bcad46bf "KVM: s390: Simplify SIGP Set Arch handling" For Ubuntu 20.04 the focal/master-next already contains: d74b0d2d38d3 KVM: s390: Clarify SIGP orders versus STOP/RESTART so we additionally need the following two upstream commits in focal 67cf68b6a5cc KVM: s390: Add a routine for setting userspace CPU state 8eeba194a32e KVM: s390: Simplify SIGP Set Arch handling
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1962578 Title: [UBUNTU 20.04] Fix SIGP processing on KVM/s390 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1962578/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
