Enlightened MSR-Bitmap feature implements a PV protocol for L0 and L1 hypervisors to collaborate and skip unneeded updates to MSR-Bitmap. KVM implements the feature for KVM-on-Hyper-V but it seems there was a flaw in the implementation and the feature may not be fully functional. PATCHes 1-2 fix the problem. The rest of the series implements the same feature for Hyper-V-on-KVM. Vitaly Kuznetsov (5): KVM: SVM: Drop stale comment from svm_hv_vmcb_dirty_nested_enlightenments() KVM: SVM: hyper-v: Enable Enlightened MSR-Bitmap support for real KVM: nSVM: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt KVM: x86: Make kvm_hv_hypercall_enabled() static inline KVM: nSVM: Implement Enlightened MSR-Bitmap feature arch/x86/kvm/hyperv.c | 12 +-------- arch/x86/kvm/hyperv.h | 6 ++++- arch/x86/kvm/svm/nested.c | 47 ++++++++++++++++++++++++++++----- arch/x86/kvm/svm/svm.c | 3 ++- arch/x86/kvm/svm/svm.h | 16 +++++++---- arch/x86/kvm/svm/svm_onhyperv.h | 12 +++------ 6 files changed, 63 insertions(+), 33 deletions(-) -- 2.33.1