On Wed, Aug 16, 2017 at 11:18:07AM +0200, Igor Mammedov wrote: > On Wed, 16 Aug 2017 09:26:51 +0800 > Dou Liyang <douly.f...@cn.fujitsu.com> wrote: > > > Currently, Using the fisrt node without memory on the machine makes > > QEMU unhappy. With this example command line: > > ... \ > > -m 1024M,slots=4,maxmem=32G \ > > -numa node,nodeid=0 \ > > -numa node,mem=1024M,nodeid=1 \ > > -numa node,nodeid=2 \ > > -numa node,nodeid=3 \ > > Guest reports "No NUMA configuration found" and the NUMA topology is > > wrong. > > > > This is because when QEMU builds ACPI SRAT, it regards node0 as the > > default node to deal with the memory hole(640K-1M). this means the > > node0 must have some memory(>1M), but, actually it can have no > > memory. > > > > Fix this problem by replace the node0 with the first node which has > > memory on it. Add a new function for each node. Also do some cleanup. > It seems harmless but one never knows for sure, > could you test it with different guests including old windows (up to XP)/ > linux (2.6 stable kernel) versions?
This patch is supposed to affect only the cases where there's no RAM configured on node 0. I won't be surprised if some guest OSes don't like it, but in this case the solution is to not configure the VM that way. That means I don't think we really need to test ancient OSes if we ensure there are no ACPI table changes on the existing known-to-work configurations. -- Eduardo