KVM: VMX: Enforce EPT pagetable level checking

We only support 4 levels EPT pagetable now.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8c9085d44c37..2201e3816205 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -340,6 +340,11 @@ static inline bool cpu_has_vmx_ept_1g_page(void)
         return vmx_capability.ept & VMX_EPT_1GB_PAGE_BIT;
 }
 
+static inline bool cpu_has_vmx_ept_4levels(void)
+{
+        return vmx_capability.ept & VMX_EPT_PAGE_WALK_4_BIT;
+}
+
 static inline bool cpu_has_vmx_invept_individual_addr(void)
 {
         return vmx_capability.ept & VMX_EPT_EXTENT_INDIVIDUAL_BIT;
@@ -1568,7 +1573,8 @@ static __init int hardware_setup(void)
         if (!cpu_has_vmx_vpid())
                 enable_vpid = 0;
 
-        if (!cpu_has_vmx_ept()) {
+        if (!cpu_has_vmx_ept() ||
+            !cpu_has_vmx_ept_4levels()) {
                 enable_ept = 0;
                 enable_unrestricted_guest = 0;
         }