The simply said "its dependencies" seems to be a dependency hell. 72fdd4de8e5 spapr: register dummy ICPs later referred to fix patch: 72194664c8a1 spapr: use spapr->vsmt to compute VCPU ids is not in Qemu 2.11, nor is the one this fixes 8904e5a75005 spapr: Adjust default VSMT value for better migration compatibility
Without testing it seems we would need: - ? marks part of the series I'm unsure it is a hard requirement but it seems entangled enough vsmt/vcpuid to consider it as well to not break functionality :-/ - f#<num> marks which other change it fixes (implicit depends) - r#<num> marks which other change depends on it #1 ? r#2 1a5008fc spapr: harden code that depends on VSMT #2 f#7 72fdd4de spapr: register dummy ICPs later #3 ? f#4 b1a568c1 spapr: fix missing CPU core nodes in DT when running with TCG #4 ? 5d0fb150 spapr: consolidate the VCPU id numbering logic in a single place #5 ? 14bb4486 rename spapr_vcpu_id() to spapr_get_vcpu_id() #6 ? 648edb64 spapr: move VCPU calculation to core machine code #7 f#9 72194664 spapr: use spapr->vsmt to compute VCPU ids #8 f#9 4ad64cbd spapr: set vsmt to MAX(8, smp_threads) #9 f#2.11 8904e5a7 spapr: Adjust default VSMT value for better migration compatibility #10 r#9 1f20f2e0 spapr: Allow some cases where we can't set VSMT mode in the kernel #1 has too much noise and isn't a hard requirement, so I skipped it There also was some noise for: - max_vthreads being renamed - on #7 for threads[0] - on #6 for POWERPC_CPU - on #6 for spapr_caps_pre_load but that was ok. Overall backport in packaged format would be: - https://git.launchpad.net/~paelzer/ubuntu/+source/qemu/commit/?id=416b00af3a8bbfc26094c4a3eba0bce09888af6c - https://git.launchpad.net/~paelzer/ubuntu/+source/qemu/commit/?id=0c93d6500d13e9eeefcf8797e0f05e0225bf9438 I made it part of the ppa that was open for bug 1762854 - so you can test both at once. => https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/3233 So it seems doable, but it is quite a huge change still. 9 patches with overall: hw/ppc/spapr.c | 160 ++++++++++++++++++++++++++++++------------------ hw/ppc/spapr_cpu_core.c | 9 -- include/hw/ppc/spapr.h | 3 OTOH it is ppc64 only so it is your (=IBM) call to make, do you want to use the backport or do you think there is a much smaller fix (changing 1-5 lines somewhere) for qemu 2.11 available to "fix just the issue"? This is a tradeoff, if it becomes too complex then the backport is clearly preferred, but if there would be a way to just handle this more comprehensively without introducing all the new VSMT handling first let me know. TL;DR I'd ask you to: - evaluate if a (much) simpler fix would be available - if not please review the backport to fit your needs - also then verify the ppa provided so that we can go forward Setting status to incomplete as I wait for feedback on that. ** Changed in: qemu (Ubuntu) Status: Triaged => Incomplete ** Changed in: ubuntu-power-systems Status: Triaged => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1763468 Title: [Ubuntu 18.04] P8 compat mode migration fails for Ubuntu 16.04.4 P8 Guest from Ubuntu 16.04.4 P8 Host -> Ubuntu 18.04 P9 Host To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1763468/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
