On 13/09/2017 22:39, Jim Mattson wrote: > I take it back. Your proposed V-x configuration isn't supported by kvm > at all. CPU_BASED_CR8_LOAD_EXITING and CPU_BASED_CR8_STORE_EXITING are > in the minimum required primary processor-based VM-execution controls > enforced by setup_vmcs_config(). So...someone else has already made > sure that setting these bits to 1 is supported. :-) Right, that's because VMs with userspace LAPIC cannot use TPR shadowing and must use CR8-load/store exiting instead. (OTOH even with kernel LAPIC a hypothetical configuration _without_ TPR shadowing could still fall back to CR8-load/store exits). Thanks, Paolo
