KVM: VMX: Inform user about INTEL_TXT dependency

Inform user to either disable TXT in the BIOS or do TXT launch
with tboot before enabling KVM since some BIOSes do not set
FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX bit when TXT is enabled.

Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8087c4d1a13658a14338d16fa2e601cc926bebcd..92612fb162dbb304343ea793702413a7481d4f30 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1305,8 +1305,11 @@ static __init int vmx_disabled_by_bios(void)
                        && tboot_enabled())
                        return 1;
                if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX)
-                       && !tboot_enabled())
+                       && !tboot_enabled()) {
+                       printk(KERN_WARNING "kvm: disable TXT in the BIOS or "
+                               " activate TXT before enabling KVM\n");
                        return 1;
+               }
        }
 
        return 0;