On 05/02/2015 07:23, Kai Huang wrote: >>> >>> + /* PML is enabled/disabled in creating/destorying vcpu */ >>> + exec_control &= ~SECONDARY_EXEC_ENABLE_PML; >> What is the harm of enabling it here? >> >> (SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES seems similar and does it.) > > Because the PML feature detection is unconditional (meaning > SECONDARY_EXEC_ENABLE_PML is always in > vmcs_config.cpu_based_2nd_exec_ctrl), but the PML buffer is only created > when vcpu is created, and it is controlled by 'enable_pml' module > parameter, if we always enable SECONDARY_EXEC_ENABLE_PML here, no PML > buffer will be created if PML is disabled by 'enable_pml' parameter, so > it's better to enable it along with creating PML buffer. I guess this is the most interesting comment from Radim. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
