[PATCH v1 2/2] KVM: VMX: always require WB memory type for EPT

[David Hildenbrand <david@redhat.com>]

We already always set that type but don't check if it is supported. Also
for nVMX, we only support WB for now. Let's just require it.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/x86/kvm/vmx.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index f6638ed..023c6dc 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1200,6 +1200,11 @@ 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_ept_mt_wb(void)
+{
+	return vmx_capability.ept & VMX_EPTP_WB_BIT;
+}
+
 static inline bool cpu_has_vmx_ept_ad_bits(void)
 {
 	return vmx_capability.ept & VMX_EPT_AD_BIT;
@@ -4302,7 +4307,6 @@ static u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa)
 {
 	u64 eptp = VMX_EPTP_MT_WB | VMX_EPTP_PWL_4;
 
-	/* TODO write the value reading from MSR */
 	if (enable_ept_ad_bits &&
 	    (!is_guest_mode(vcpu) || nested_ept_ad_enabled(vcpu)))
 		eptp |= VMX_EPTP_AD_ENABLE_BIT;
@@ -6638,7 +6642,8 @@ static __init int hardware_setup(void)
 		init_vmcs_shadow_fields();
 
 	if (!cpu_has_vmx_ept() ||
-	    !cpu_has_vmx_ept_4levels()) {
+	    !cpu_has_vmx_ept_4levels() ||
+	    !cpu_has_vmx_ept_mt_wb()) {
 		enable_ept = 0;
 		enable_unrestricted_guest = 0;
 		enable_ept_ad_bits = 0;
-- 
2.9.4