On Wed, Oct 29, 2025 at 11:00:18PM +0530, Shivaprasad G Bhat wrote: > Hi Michal, > > On 10/21/25 4:37 PM, Michal Suchánek wrote: > > Hello, > > > > I noticed removal of old pSeries revisions. > > > > FTR to boot Linux 3.0 I need pSeries-2.7 (already removed earlier). > > > > The thing that broke booting linux 3.0 for me is > > 357d1e3bc7d2d80e5271bc4f3ac8537e30dc8046 spapr: Improved placement of > > PCI host bridges in guest memory map > > > > I do not use Linux 3.0 anymore which is the reason I did not notice this > > breakage due to old platform revision removal. > > I tried booting linux kernel 3.13.0-170-generic from ubuntu 14.04.6 LTS with > the oldest supported machine pseries-5.0 as of now. > > It worked fine. > > > qemu-system-ppc64 -machine pseries-5.0 -accel tcg -nographic -m size=12G > -cpu power8 -smp 1 -drive > file=/root/images/ubuntu16.04.qcow2,format=qcow2,if=none,id=drive-virtio-disk0 > -device virtio-blk-pci,drive=drive-virtio-disk0,id=virtio-disk0 -serial > mon:stdio -kernel /root/images/vmlinux-3.13.0-170-generic -initrd > /root/images/initrd.img-3.13.0-170-generic -append > "BOOT_IMAGE=/boot/vmlinux-4.4.0-142-generic > root=UUID=94fba90c-dbb0-4f8d-bc3e-acd5f2e54749 ro vt.handoff=7" > > > shiva@ubuntu:~$ uname -a > Linux ubuntu 3.13.0-170-generic #220-Ubuntu SMP Thu May 9 12:44:25 UTC 2019 > ppc64le ppc64le ppc64le GNU/Linux > shiva@ubuntu:~$ cat /proc/cpuinfo > processor : 0 > cpu : POWER8 (architected), altivec supported > clock : 1000.000000MHz > revision : 2.0 (pvr 004d 0200) > > timebase : 512000000 > platform : pSeries > model : IBM pSeries (emulated by qemu) > machine : CHRP IBM pSeries (emulated by qemu) > > > Hope that helps.
How does that help? Of course newer kernels do work. However, distributions using Linux 3.0 don't anymore, at least that particular Linux 3.0 build. I am not particularly concerned, only noting that the qemu pSeries emulation is not suitable for running very old distributions because they are not compatible with newer qemu. It can be a bug in the old kernel but it's not triggered by actual hardware nor older qemu. Or it may bee a bug with that new qemu PCI bus organization that is not triggered by newer kernel. I don't know and since nobody cared enough to diagnose it so far we will probably never know. Thanks Michal
