"David Hildenbrand (Red Hat)" <[email protected]> writes: > On 11/28/25 06:05, Ritesh Harjani (IBM) wrote: >> "David Hildenbrand (Red Hat)" <[email protected]> writes: >> >>> On 10/21/25 12:06, David Hildenbrand wrote: >>>> Two smaller fixes identified while doing a bigger rework. >>>> >>>> Compile-tested only as I don't have an easy way to test right now. >>>> >>>> I would prefer for these patches to go through the MM tree as I will >>>> be sending out a bigger version soon that is based on this series -- >>>> I split of the fixes from the other stuff. >>>> >>> >>> Ping, >>> >>> I tried to get CMM running again (using the simulation mode I introduced >>> a while back), but so far my attempts to get a reasonable powernv VM >>> booted in QEMU failed :( >>> >>> (e.g., Fedora qcow2 images use xfs, but the open powernv loader is based >>> on a 5.10 kernel without some mystical XFS feature ...) >>> >> > > Hi Ritesh, > >> Sorry, I missed seeing this earlier. >> >> Do you have the link to simulation mode which you are referring above >> please? So far I didn't find the support of this beyond Linux LPAR >> (pseries), but maybe I missed it. > > When I did a rework of the CMM balloon in 2019, I needed a way to test > it. So I added > > commit b1713975c31ae20ecc40fd00191ee3fa51445d4a > Author: David Hildenbrand <[email protected]> > Date: Thu Oct 31 15:29:31 2019 +0100 > > powerpc/pseries/cmm: Simulation mode
aah right. I should have looked closely. I was thinking you meant somewhere in Qemu, so I was only looking there. > > Let's allow to test the implementation without needing HW support. > When "simulate=1" is specified when loading the module, we bypass all > HW checks and HW calls. The sysfs file "simulate_loan_target_kb" can > be used to simulate HW requests. > > The simualtion mode can be activated using: > modprobe cmm debug=1 simulate=1 > > And the requested loan target can be changed using: > echo X > /sys/devices/system/cmm/cmm0/simulate_loan_target_kb > > > I allows for bypassing the absence of FW_FEATURE_CMO. > Right. Let me give it a try first with pseries Qemu. Otherwise I have an access to pseries LPAR too. I can verify it there. > Back in the days I was able to test it with a pseries (or was it powernv?) Agree the name can be a bit confusing. So powernv == Power Non-Virtualized that's the baremetal Power box. pseries == is basically the Linux LPAR on PowerVM. Qemu/KVM also has support for booting Linux pseries guest. > machine we had here at RH. So far my attempts failed to test it in a > similar fashion in QEMU. > Let me give it a try and I will update how it goes. Thanks! -ritesh
