[PATCH v2 09/13] nEPT: Advertise EPT to L1

[Jun Nakajima <jun.nakajima@intel.com>]

Advertise the support of EPT to the L1 guest, through the appropriate MSR.

This is the last patch of the basic Nested EPT feature, so as to allow
bisection through this patch series: The guest will not see EPT support until
this last patch, and will not attempt to use the half-applied feature.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Xinhao Xu <xinhao.xu@intel.com>
---
 arch/x86/include/asm/vmx.h |  2 ++
 arch/x86/kvm/vmx.c         | 17 +++++++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index b6fbf86..79a5beb 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -376,7 +376,9 @@ enum vmcs_field {
 #define VMX_EPTP_WB_BIT				(1ull << 14)
 #define VMX_EPT_2MB_PAGE_BIT			(1ull << 16)
 #define VMX_EPT_1GB_PAGE_BIT			(1ull << 17)
+#define VMX_EPT_INVEPT_BIT			(1ull << 20)
 #define VMX_EPT_AD_BIT				    (1ull << 21)
+#define VMX_EPT_EXTENT_INDIVIDUAL_BIT		(1ull << 24)
 #define VMX_EPT_EXTENT_CONTEXT_BIT		(1ull << 25)
 #define VMX_EPT_EXTENT_GLOBAL_BIT		(1ull << 26)
 
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 419b9e3..de6cfb4 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2027,6 +2027,7 @@ static u32 nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high;
 static u32 nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high;
 static u32 nested_vmx_exit_ctls_low, nested_vmx_exit_ctls_high;
 static u32 nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high;
+static u32 nested_vmx_ept_caps;
 static __init void nested_vmx_setup_ctls_msrs(void)
 {
 	/*
@@ -2102,6 +2103,18 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	nested_vmx_secondary_ctls_low = 0;
 	nested_vmx_secondary_ctls_high &=
 		SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
+	if (enable_ept) {
+		/* nested EPT: emulate EPT also to L1 */
+		nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT;
+		nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT;
+		nested_vmx_ept_caps |=
+			VMX_EPT_INVEPT_BIT | VMX_EPT_EXTENT_GLOBAL_BIT |
+			VMX_EPT_EXTENT_CONTEXT_BIT |
+			VMX_EPT_EXTENT_INDIVIDUAL_BIT;
+		nested_vmx_ept_caps &= vmx_capability.ept;
+	} else
+		nested_vmx_ept_caps = 0;
+
 }
 
 static inline bool vmx_control_verify(u32 control, u32 low, u32 high)
@@ -2201,8 +2214,8 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
 					nested_vmx_secondary_ctls_high);
 		break;
 	case MSR_IA32_VMX_EPT_VPID_CAP:
-		/* Currently, no nested ept or nested vpid */
-		*pdata = 0;
+		/* Currently, no nested vpid support */
+		*pdata = nested_vmx_ept_caps;
 		break;
 	default:
 		return 0;
-- 
1.8.1.2