[PATCH v1] KVM: VMX: require EPT WB (Write Back) memory type

[David Hildenbrand]

Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 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 78c66a7..a2f8475 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1192,6 +1192,11 @@ 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_wb_bit(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;
@@ -4260,7 +4265,6 @@ static u64 construct_eptp(struct kvm_vcpu *vcpu,
unsigned long root_hpa)
 {
 	u64 eptp;

-	/* TODO write the value reading from MSR */
 	eptp = VMX_EPT_DEFAULT_MT |
 		VMX_EPT_DEFAULT_GAW << VMX_EPT_GAW_EPTP_SHIFT;
 	if (enable_ept_ad_bits &&
@@ -6579,7 +6583,8 @@ 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_wb_bit()) {
 		enable_ept = 0;
 		enable_unrestricted_guest = 0;
 		enable_ept_ad_bits = 0;
-- 
2.9.4


-- 

Thanks,

David