Re: [PATCH v6 2/3] KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL

From: Paolo Bonzini
Date: Thu Jul 11 2019 - 09:25:18 EST

On 21/06/19 07:57, Tao Xu wrote:
> + if (guest_cpuid_has(vcpu, X86_FEATURE_WAITPKG))
> + atomic_switch_umwait_control_msr(vmx);
> +

guest_cpuid_has is slow. Please replace it with a test on

Are you going to look into nested virtualization support? This should
include only 1) allowing setting the enable bit in secondary execution
controls, and passing it through in prepare_vmcs02_early; 2) reflecting
the vmexit in nested_vmx_exit_reflected.