------- Comment From harih...@in.ibm.com 2019-02-20 00:30 EDT------- The method mentioned in comment 9 is to use module parameter to change the value of max_mem_regions. Which is working and hotplug happens upto the 256 times.
How ever the same solution may not be useful in the production environment. To set the module parameter we have remove the module first, to do so we have to bring down all running guests. I would be always goo to set the max_mem_regions to set to max value say 512. That will enable hotplug on production environment with out bring down and modules or guests. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1796839 Title: Only 64 Memory regions or dimms supported for Hotplug. Status in The Ubuntu-power-systems project: Won't Fix Status in linux package in Ubuntu: Invalid Bug description: == Comment: #0 - HARIHARAN T. SUNDARESH REDDY <harih...@in.ibm.com> - 2018-10-03 01:29:59 == Description : Hotplug is supported only for 64 dimms and the same is controlled by the sysfs parameter # cat /sys/module/vhost/parameters/max_mem_regions 64 However qemu supports 256 slots max. In my opinion max_mem_regions must be >= 256. log : 63 Device attached successfully <--- 63 times devices attached successfully, later all attach failed. 64 error: Failed to attach device from hp_mem.xml error: internal error: unable to execute QEMU command 'device_add': a used vhost backend has no free memory slots left 65 error: Failed to attach device from hp_mem.xml error: internal error: unable to execute QEMU command 'device_add': a used vhost backend has no free memory slots left 66 error: Failed to attach device from hp_mem.xml error: internal error: unable to execute QEMU command 'device_add': a used vhost backend has no free memory slots left System Details : uname -a Linux ltc-fvttest 4.18.5-custom #1 SMP Wed Sep 26 12:11:51 CDT 2018 ppc64le ppc64le ppc64le GNU/Linux root@ltc-fvttest:/home/hariharan# cat /etc/os-release NAME="Ubuntu" VERSION="18.10 (Cosmic Cuttlefish)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu Cosmic Cuttlefish (development branch)" VERSION_ID="18.10" HOME_URL="https://www.ubuntu.com/"; SUPPORT_URL="https://help.ubuntu.com/"; BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"; PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"; VERSION_CODENAME=cosmic UBUNTU_CODENAME=cosmic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1796839/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
