This is an initial implementation of Enlightened VMCS for nested Hyper-V on KVM. Using it helps to spare 1500 cpu cycles for nested vmexit (tight cpuid loop in WS2016 with Hyper-V role on KVM: 15200 cycles -> 13700 cycles). Changes since RFCv2: - Rename sync_shadow_vmcs to need_vmcs12_sync and reuse for eVMCS case [Paolo Bonzini] Ladi Prosek (1): KVM: hyperv: define VP assist page helpers Vitaly Kuznetsov (4): KVM: nVMX: add KVM_CAP_HYPERV_ENLIGHTENED_VMCS capability KVM: nVMX: add enlightened VMCS state KVM: nVMX: implement enlightened VMPTRLD and VMCLEAR KVM: nVMX: optimize prepare_vmcs02{,_full} for Enlightened VMCS case arch/x86/include/asm/kvm_host.h | 3 + arch/x86/kvm/hyperv.c | 23 +- arch/x86/kvm/hyperv.h | 4 + arch/x86/kvm/lapic.c | 4 +- arch/x86/kvm/lapic.h | 2 +- arch/x86/kvm/svm.c | 9 + arch/x86/kvm/vmx.c | 810 +++++++++++++++++++++++++++++++++------- arch/x86/kvm/x86.c | 17 +- include/uapi/linux/kvm.h | 1 + 9 files changed, 724 insertions(+), 149 deletions(-) -- 2.14.4