Commit c4327f15dfc7 ("KVM: SVM: hyper-v: Enlightened MSR-Bitmap support") introduced enlightened MSR-Bitmap support for KVM-on-Hyper-V but it didn't actually enable the support. Similar to enlightened NPT TLB flush and direct TLB flush features, the guest (KVM) has to tell L0 (Hyper-V) that it's using the feature by setting the appropriate feature fit in VMCB control area (sw reserved fields). Fixes: c4327f15dfc7 ("KVM: SVM: hyper-v: Enlightened MSR-Bitmap support") Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- arch/x86/kvm/svm/svm_onhyperv.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h index cdbcfc63d171..489ca56212c6 100644 --- a/arch/x86/kvm/svm/svm_onhyperv.h +++ b/arch/x86/kvm/svm/svm_onhyperv.h @@ -46,6 +46,9 @@ static inline void svm_hv_init_vmcb(struct vmcb *vmcb) if (npt_enabled && ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB) hve->hv_enlightenments_control.enlightened_npt_tlb = 1; + + if (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP) + hve->hv_enlightenments_control.msr_bitmap = 1; } static inline void svm_hv_hardware_setup(void) -- 2.33.1