From: David Hildenbrand <david@redhat.com>
Date: Thu, 10 Aug 2017 23:15:29 +0200
Subject: KVM: VMX: always require WB memory type for EPT
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Patch-mainline: v4.14-rc1
Git-commit: 42aa53b4e1c05212baf63842515b22920241e5e1
References: bsc#1077761

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>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
---
 arch/x86/kvm/vmx.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1195,6 +1195,11 @@
 	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;
@@ -4290,7 +4295,6 @@
 {
 	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;
@@ -6618,7 +6622,8 @@
 		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;