Commit e2e871ab2f02 ("x86/kvm/hyper-v: Introduce nested_get_evmcs_version() helper") broke EVMCS enablement: to set vmcs_version we now call nested_get_evmcs_version() but this function checks enlightened_vmcs_enabled flag which is not yet set so we end up returning zero. Fix the issue by re-arranging things in nested_enable_evmcs(). Fixes: e2e871ab2f02 ("x86/kvm/hyper-v: Introduce nested_get_evmcs_version() helper") Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- arch/x86/kvm/vmx/evmcs.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c index 95bc2247478d..5466c6d85cf3 100644 --- a/arch/x86/kvm/vmx/evmcs.c +++ b/arch/x86/kvm/vmx/evmcs.c @@ -332,16 +332,17 @@ int nested_enable_evmcs(struct kvm_vcpu *vcpu, uint16_t *vmcs_version) { struct vcpu_vmx *vmx = to_vmx(vcpu); + bool evmcs_already_enabled = vmx->nested.enlightened_vmcs_enabled; + + vmx->nested.enlightened_vmcs_enabled = true; if (vmcs_version) *vmcs_version = nested_get_evmcs_version(vcpu); /* We don't support disabling the feature for simplicity. */ - if (vmx->nested.enlightened_vmcs_enabled) + if (evmcs_already_enabled) return 0; - vmx->nested.enlightened_vmcs_enabled = true; - vmx->nested.msrs.pinbased_ctls_high &= ~EVMCS1_UNSUPPORTED_PINCTRL; vmx->nested.msrs.entry_ctls_high &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL; vmx->nested.msrs.exit_ctls_high &= ~EVMCS1_UNSUPPORTED_VMEXIT_CTRL; -- 2.20.1