As specified in Intel's SDM, do not allow the L1 hypervisor to launch
an L2 guest with the VM-execution controls for "unrestricted guest" or
"mode-based execute control for EPT" set and the VM-execution control
for "enable EPT" clear.
Note that the VM-execution control for "mode-based execute control for
EPT" is not yet virtualized by kvm.
Reported-by: Andrew Thornton <andrewth@xxxxxxxxxx>
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
---
arch/x86/include/asm/vmx.h | 1 +
arch/x86/kvm/vmx.c | 13 +++++++++++++
2 files changed, 14 insertions(+)
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 9527ba5d62da..665632a4b54b 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -78,6 +78,7 @@
#define SECONDARY_EXEC_RDSEED_EXITING 0x00010000
#define SECONDARY_EXEC_ENABLE_PML 0x00020000
#define SECONDARY_EXEC_XSAVES 0x00100000
+#define SECONDARY_EXEC_MODE_BASED_EPT_EXEC 0x00400000
#define SECONDARY_EXEC_TSC_SCALING 0x02000000
#define PIN_BASED_EXT_INTR_MASK 0x00000001
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1d26f3c4985b..2bf990b5848f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11719,6 +11719,16 @@ static int nested_vmx_check_pml_controls(struct kvm_vcpu *vcpu,
return 0;
}
+static int nested_vmx_check_ept_enable(struct kvm_vcpu *vcpu,
+ struct vmcs12 *vmcs12)
+{
+ if ((nested_cpu_has2(vmcs12, SECONDARY_EXEC_UNRESTRICTED_GUEST) ||
+ nested_cpu_has2(vmcs12, SECONDARY_EXEC_MODE_BASED_EPT_EXEC)) &&
+ !nested_cpu_has_ept(vmcs12))
+ return -EINVAL;
+ return 0;
+}
+
static int nested_vmx_check_shadow_vmcs_controls(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
@@ -12339,6 +12349,9 @@ static int check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
if (nested_vmx_check_pml_controls(vcpu, vmcs12))
return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+ if (nested_vmx_check_ept_enable(vcpu, vmcs12))
+ return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
if (nested_vmx_check_shadow_vmcs_controls(vcpu, vmcs12))
return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
--
2.19.0.rc0.228.g281dcd1b4d0-goog
