On Fri, 1 Apr 2022 23:50:16 +0000 "Kallol Biswas [C]" <kallol.biswas@xxxxxxxxxxx> wrote: > Hi, > We are observing a problem with CPU hotplug. > > If secureboot option is enabled under UEFI and then if we try to do CPU hotplug the VM crashes/just reboots. > > No crash dump is generated, no panic message, just VM restarts. Issue seems like: > https://bugzilla.redhat.com/show_bug.cgi?id=1834250 CPU hotplug with SMM (for q35) was merged in QEMU-5.2 and unplug part in 6.0, you also need a matching OVMF build to make it work. Later upto 6.2 (included) there were minor fixes dealing with incorrect configs. > What are the debugging techniques we can apply to halt the VM and examine what's going on? > VM has been configured with crash dump. I'd start with https://www.linux-kvm.org/page/Tracing to find out when it goes south. > Nucleodyne at Nutanix > 408-718-8164 >