GitHub user StepBee closed the discussion with a comment: Installation of Windows Server 2025 on KVM Hypervisors in bootloop
@SviridoffA we experienced the issue when upgrading from Ubuntu 20.04 Kernel 5.4.0-174-generic to Ubuntu 24.04 Kernel 6.8.0-60-generic. But observed this change in the kernel was happening already at version 5.15.0-153-generic as well. I would assume this should have happened across all Linux OS - but have no other hosts to prove it. The error appearing in our case whentrying to live migrate from non-updated hosts to an already updated host was `qemu-system-x86_64: error: failed to set MSR 0x38f to 0xf000000ff qemu-system-x86_64: target/i386/kvm/kvm.c:3210: kvm_buf_set_msrs: Assertion ret == cpu->kvm_msr_buf->nmsrs' failed.` The combination of the Intel Xeon Gold CPU and the new kernel version with new features surprisingly brought up more performance counters, visible for example executing Old kernel: ``` # rdmsr 0x38f f000000ff ``` New kernel: ``` # rdmsr 0x38f 1000f000000ff ``` Even after extensive research and testing, we have not been able to track this down to a specific CPU flag (which we potentially could have disabled) or any other feature to enable live migration again. GitHub link: https://github.com/apache/cloudstack/discussions/11714#discussioncomment-14700869 ---- This is an automatically sent email for [email protected]. To unsubscribe, please send an email to: [email protected]
