On Thu, 3 Mar 2022 11:25:25 +0800 Gavin Shan <gs...@redhat.com> wrote:
> Hi Gerd, > > On 3/1/22 7:42 PM, Gerd Hoffmann wrote: > >>> Unless it architecturally wrong thing i.e. (node size less than 128Mb) > >>> ,in which case limiting it in QEMU would be justified, I'd prefer > >>> firmware being fixed or it reporting more useful for user error message. > >> > >> [include EDK2 developers] > >> > >> I don't think 128MB node memory size is architecturally required. > >> I also thought EDK2 would be better place to provide a precise error > >> mesage and discussed it through with EDK2 developers. Lets see what > >> are their thoughts this time. > > > > Useful error reporting that early in the firmware initialization is a > > rather hard problem, it's much easier for qemu to catch those problems > > and print a useful error message. > > > > Fixing the firmware would be possible. The firmware simply uses the > > memory of the first numa note in the early initialization phase, which > > could be changed to look for additional numa nodes. It's IMHO simply > > not worth the trouble though. numa nodes with less memory than 128M > > simply doesn't happen in practice, except when QE does questionable > > scaleability testing (scale up the number of numa nodes without also > > scaling up the total amount of memory, ending up with rather tiny > > numa nodes and a configuration nobody actually uses in practice). > > > > I still don't think QEMU is best place to have this kind of limitation, > which the first NUMA node should have 128MB memory at least. For example, > the limitation exists in EDK2-version-A.0 and the limitation is removed > in EDK2-version-A.1. The QEMU can't boot the guest using EDK2-version-A.1, > but we should succeed. if firmware is not an option, I wouldn't opposed to printing warning message from QEMU if you can detect that you are running broken edk2 and under condition that no new infa/hooks are invented for this. (assuming it's worth all the effort at all) Maybe put it in virt-arm specific machine_done. > If it's not worthwhile to be fixed in EDK2, it might be doable to improve > the error message printed by EDK2. Otherwise, we would ignore this issue > because 128MB node memory size isn't used in practice. If the EDK2 error > message can be improved, we might have something like below: > > ASSERT [MemoryInit] > /home/lacos/src/upstream/qemu/roms/edk2/ArmVirtPkg/Library/QemuVirtMemInfoLib/QemuVirtMemInfoPeiLibConstructor.c(93): > NewSize >= 0x08000000 > > to > > The first NUMA node should have more than 128MB memory > > Thanks, > Gavin >
