On 29/05/19 04:05, Tao Xu wrote: >> > > Thank you Paolo, but I have another question. I was wondering if it is > appropriate to enable X86_FEATURE_WAITPKG when QEMU uses "-overcommit > cpu-pm=on"? "-overcommit" only establishes the behavior of KVM, it doesn't change the cpuid bits. So you'd need "-cpu" as well. Paolo > Or just enable X86_FEATURE_WAITPKG when QEMU add the feature > "-cpu host,+waitpkg"? User wait instructions is the wait or pause > instructions may be executed at any privilege level, but can use > IA32_UMWAIT_CONTROL to set the maximum time.