Previously, it was not possible to send an non-maskable interrupt (NMI) to a non-responsive guest operating system. In this release, users can send an NMI via the Cockpit. A new menu option called "Send Non-Maskable Interrupt" was added to the "Shut Down" menu that is available from the Virtual Machines tab. It sends a 'virsh inject-nmi' command to the required virtual machine, and it is sent regardless of the virtual machine's state and without checking the type of operating system or its settings. In the event of an operation system that is not installed or configured correctly, no action will be taken. More info: This feature can be used with any OS and any configuration. The only must requirement is that an OS should be installed because a VM without OS will remain unresponsive for NMI. We can just mention that in case of Linux OS, we suggest to configure the OS to handle/not ignore the non-maskable interrupt (because otherwise there is no meaning for sending it and the VM will remain unresponsive) and this can be done by: 1. setting those 2 kernel properties to "1" - for switching the OS to panic mode in case of receiving a NMI. 2. By enabling the kdump service - for creating crash dumps in case of switching to panic mode: service kdump start But the user can choose to handle this NMI however he likes. > 2. What would be the symptom of the VM being non-responsive that would lead > someone to use this feature? A non responsive VM is a VM that can't be reached by libvirt and specifically that shutdown/restart/destroy are not working for him.
Emma, Please take a look at the new topic: http://file.tlv.redhat.com/~sgoodman/BZ%231506260-Administration_Guide/#Handling_a_Non-Responsive_Virtual_Machine Merge request is here: https://gitlab.cee.redhat.com/rhci-documentation/docs-Red_Hat_Enterprise_Virtualization/merge_requests/1092
Verified.
This is now published as a Knowledgebase article. The URL is: https://access.redhat.com/articles/3587631