> Date: Fri, 27 Aug 2021 18:02:59 +0200 > From: Greg Kurz <gr...@kaod.org> > > On Fri, 27 Aug 2021 15:12:31 +0000 > Joseph <joseph.ma...@protonmail.com> wrote: > > > On Friday, August 27th, 2021 at 11:01 PM, Greg Kurz <gr...@kaod.org> wrote: > > > Linux knows how to drive both powernv and pseries platforms. > > .. > > > OpenBSD might have to implement proper guest-side pseries > > > support to run as a guest under an hypervisor on POWER. I don't > > > know OpenBSD but this likely a huge effort. > > > > > > More details in the "Linux on POWER Architecture Reference": > > > https://openpowerfoundation.org/wp-content/uploads/2020/07/LoPAR-20200611.pdf > > > and under the arch/powerpc/platforms/pseries/ directory in the linux > > > kernel sources. > > > > Hi Greg, > > > > Thanks for following up. > > > > (Meanwhile I posted this Q to KVM-PPC and QEMU-PPC too. On the latter it's > > https://lists.nongnu.org/archive/html/qemu-ppc/2021-08/msg00416.html and on > > the further it didn't register yet.) > > > > First I believe KVM-QEMU and "PowerKVM" are different - the latter was > > a KVM fork maintained by IBM. The further is just the KVM and QEMU > > repo. Did IBM their contributions so PowerKVM was upstreamed, you tell > > me. > > > > Yes you're right that PowerKVM was an IBM internal fork of KVM and > QEMU, but it was discontinued ages ago. All the relevant bits have > been merged upstream and all development since then happens upstream. > So it doesn't make a big difference now to use PowerKVM instead of > QEMU-KVM on POWER. > > > Are you saying that KVM-QEMU has all relevant Power9 support > > already, for a Linux host OpenBSD as a guest on bare metal > > ("powernv" mode)? > > > > There's some confusion here. In bare metal, you just have a single > instance of the OS running unvirtualized directly on the host. > KVM-QEMU isn't involved at all in this case. According to the OpenBSD > statement, you can already install and run it in this mode on an > OpenPOWER system.
Correct. > > In this case why would there be any relevance in OpenBSD implementing > > pseries. > > > > If you want to also run OpenBSD inside a VM, then OpenBSD must > implement proper support to be able to run in the paravirtualized > PAPR environment provided by KVM-QEMU on POWER. The OpenBSD statement > seem to indicate this is missing. Nothing special "should" be needed > on the KVM-QEMU side. Indeed. OpenBSD/powerpc64 currently does not implement PAPR environment support. I've looked at it at some point and I don't think adding support for it would be impossible. But I only have powernv hardware. I suppose I could run KVM-QEMU on Linux on that but my time is limited. It is possible to use QEMU to emulate a powernv machine and in principle you can run OpenBSD in that environment on a Linux host. But that's emulation and not virtualization. It doesn't seem to work though and the installer hangs after printing its first message. I suspect QEMU's emulation of the XIVE interrupt controller isn't 100% faithful. It's also really slow when running on an amd64 machine, so I didn't investigate further.
