On 04/04/22 14:36, Igor Mammedov wrote: > 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 >> > Also don't forget to build OVMF with DEBUG_VERBOSE (set gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel to 0x8040004F), and to capture the OVMF debug log (-debugcon file:debug.log -global isa-debugcon.iobase=0x402). Laszlo
