[PATCH v2] KVM VMX: Make sure single type invvpid is supported before issuing invvpid instruction

[Gui Jianfeng <guijianfeng@cn.fujitsu.com>]

According to SDM, we need check whether single-context INVVPID type is supported
before issuing invvpid instruction.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
---
 arch/x86/include/asm/vmx.h |    2 ++
 arch/x86/kvm/vmx.c         |   14 +++++++++++++-
 2 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 104cf86..4e78b25 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -376,6 +376,8 @@ enum vmcs_field {
 #define VMX_EPT_EXTENT_CONTEXT_BIT		(1ull << 25)
 #define VMX_EPT_EXTENT_GLOBAL_BIT		(1ull << 26)
 
+#define VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT      (1ull << 9)
+
 #define VMX_EPT_DEFAULT_GAW			3
 #define VMX_EPT_MAX_GAW				0x4
 #define VMX_EPT_MT_EPTE_SHIFT			3
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0e561a5..f363fe3 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -355,6 +355,17 @@ static inline bool cpu_has_vmx_invept_global(void)
 	return vmx_capability.ept & VMX_EPT_EXTENT_GLOBAL_BIT;
 }
 
+static inline bool cpu_has_vmx_invvpid_single(void)
+{
+	/* 
+	 *  bit 41 of IA32_VMX_EPT_VPID_CAP MSR indicates whehter the 
+	 *  single-context INVVPID type is supported. vmx_capability.vpid 
+	 *  represents the higher 32 bits of IA32_VMX_EPT_VPID_CAP MSR, so
+	 *  VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT(bit 9) is used here.
+	 */
+	return vmx_capability.vpid & VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT;
+}
+
 static inline bool cpu_has_vmx_ept(void)
 {
 	return vmcs_config.cpu_based_2nd_exec_ctrl &
@@ -499,7 +510,8 @@ static inline void vpid_sync_vcpu_all(struct vcpu_vmx *vmx)
 	if (vmx->vpid == 0)
 		return;
 
-	__invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vmx->vpid, 0);
+	if (cpu_has_vmx_invvpid_single())
+		__invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vmx->vpid, 0);
 }
 
 static inline void ept_sync_global(void)
-- 
1.6.5.2