Comment 2 for bug 1841066

qemu head (4.2 dev) - works
v4.1.0 - works
v4.0.0 - fails (well we know it is post 4.0 code so that is fine).

That called for a bisect:

BAD = once the feature is detected:
git bisect start
# bad: [9e06029aea3b2eca1d5261352e695edc1e7d7b8b] Update version for v4.1.0 release
git bisect bad 9e06029aea3b2eca1d5261352e695edc1e7d7b8b
# good: [131b9a05705636086699df15d4a6d328bb2585e8] Update version for v4.0.0 release
git bisect good 131b9a05705636086699df15d4a6d328bb2585e8
# good: [aae65009726858390d8bfca73d795613698f317a] s390x/tcg: Export float_comp_to_cc() and float(32|64|128)_dcmask()
git bisect good aae65009726858390d8bfca73d795613698f317a
# skip: [efa85a4d1ab13e962c0a93d09b7e935571d669fe] Merge remote-tracking branch 'remotes/philmd-gitlab/tags/pflash-next-20190701' into staging
git bisect skip efa85a4d1ab13e962c0a93d09b7e935571d669fe
# bad: [b28f582c2acaca26b66262d75cc5a0bd2764482c] iotests: Let 233 run concurrently
git bisect bad b28f582c2acaca26b66262d75cc5a0bd2764482c
# bad: [14e714900f6b90b35ae2b040d300f95581a416f4] spapr: Allow hot plug/unplug of PCI bridges and devices under PCI bridges
git bisect bad 14e714900f6b90b35ae2b040d300f95581a416f4
# good: [2fc0cc0e1e034582f4718b1a2d57691474ccb6aa] target/arm: Use env_cpu, env_archcpu
git bisect good 2fc0cc0e1e034582f4718b1a2d57691474ccb6aa
# good: [677c4d69ac21961e76a386f9bfc892a44923acc0] cpu: Move ENV_OFFSET to exec/gen-icount.h
git bisect good 677c4d69ac21961e76a386f9bfc892a44923acc0
# bad: [506174bf8219dc6d56d2b1f7e66e8cf39157466f] i386: "unavailable-features" QOM property
git bisect bad 506174bf8219dc6d56d2b1f7e66e8cf39157466f
# good: [65b23204d609c5aac819049c2d7314b4abd73122] tcg/aarch64: Use LDP to load tlb mask+table
git bisect good 65b23204d609c5aac819049c2d7314b4abd73122
# good: [43b3952dea0f763ceeaa2f119c473b5cc6d29c90] tcg/arm: Remove mostly unreachable tlb special case
git bisect good 43b3952dea0f763ceeaa2f119c473b5cc6d29c90
# good: [5a853fc57a0860da4a55d1448a77845f97e7a9be] i386: x86_cpu_list_feature_names() function
git bisect good 5a853fc57a0860da4a55d1448a77845f97e7a9be
# first bad commit: [506174bf8219dc6d56d2b1f7e66e8cf39157466f] i386: "unavailable-features" QOM property

P.S. some nice fast build time helped this bisect :-)