s390/sclp: temporarily fix unassignment/reassignment of memory subregions
Commit 374f2981 ("memory: protect current_map by RCU") broke unassignment of standby memory on s390x. Looks like that the new parallelism allows races with our (semi broken) memory hotplug code. The flatview_unref() can now be executed after our unparenting. Therefore memory_region_unref() tries to unreference the MemoryRegion itself instead of the parent. In theory, MemoryRegions are now bound to separate devices that control their lifetime. We don't have this yet, so we really want to control their lifetime manually. This patch fixes it temporarily, until we have a proper rework. The only drawback is that they won't pop up in "info qom-tree", but that's better than qemu crashes. We have to release the reference to a memory region after a memory_region_find, as it automatically takes a reference. As we're now able to reassign memory, the MemoryRegion is in fact deleted (otherwise vmstate_register_ram() would complain). Reviewed-by: NMatthew Rosato <mjrosato@linux.vnet.ibm.com> Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Showing
想要评论请 注册 或 登录