As pointed out by Cédric 1, POWER8 is a little old. We moved from
POWER9 to POWER8 in commit 29f7dba ("boot-qemu.sh: Specify POWER8 CPUs
for ppc64 and ppc64le") because of the rootfs, which works fine on a
POWER9 machine as well, which is the current meaning of the 'powernv'
machine. This has been tested with all the images from
continuous-integration2 to ensure it is safe for all the versions we
test.
As pointed out by Cédric 1, POWER8 is a little old. We moved from POWER9 to POWER8 in commit 29f7dba ("boot-qemu.sh: Specify POWER8 CPUs for ppc64 and ppc64le") because of the rootfs, which works fine on a POWER9 machine as well, which is the current meaning of the 'powernv' machine. This has been tested with all the images from continuous-integration2 to ensure it is safe for all the versions we test.