Hi all, looking for hints on a wild crash. The company I work for has a kernel driver used to literally make a db query result look like a filesystem… The “database” in question being a proprietary SCM repository… (ClearCase, for those who have been around forever… Like me…) We have a crash on mounting the remote repository ONE way (ClearCase “Automatic views”) but not another (ClearCase “Dynamic views”) where both use the same kernel driver… The guest OS is RHEL 7.8, not registered with RH (since the VM is only supposed to last a couple of days.) The host OS is Ubuntu 20.04.2 LTS, though that does not seem to matter. The wild part is that this only happens when the ClearCase host is a KVM guest, and only on 6th-generation or newer . It does NOT happen on: * VMWare Virtual machines configured identically * VirtualBox Virtual machines Configured identically * 2nd generation intel core hosts running the same KVM release. (because OF COURSE my office "secondary desktop" host is ancient... * A 4th generation I7 host running Ubuntu 22.04 and that version’s default KVM. (Because I am a laptop packrat. That laptop had been sitting on a bookshelf for 3+ years and I went "what if...") If I edit the KVM configuration and change the “mirror host CPU” option to use the 2nd or 4th generation CPU options, the crash stops happening… If this was happening on physical machines, the VM crash would make sense, but it's literally a hypervisor-specific crash. Any hints, tips, or comments would be most appreciated... Never thought I'd be trying to debug kernel/hypervisor interactions, but here I am...
