KVM: Use standard CR4 flags, tighten checking

On this machine (Intel), writing to the CR4 bits 0x00000800 and
0x00001000 cause a GPF.  The Intel manual is a little unclear, but
AFIACT they're reserved, too.

Also fix spelling of CR4_RESEVED_BITS.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 983c33f..25439a5 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -23,12 +23,6 @@
 #define CR3_NONPAE_RESERVED_BITS ((PAGE_SIZE-1) & ~(X86_CR3_PWT | X86_CR3_PCD))
 #define CR3_L_MODE_RESERVED_BITS (CR3_NONPAE_RESERVED_BITS|0xFFFFFF0000000000ULL)
 
-#define CR4_VME_MASK (1ULL << 0)
-#define CR4_PSE_MASK (1ULL << 4)
-#define CR4_PAE_MASK (1ULL << 5)
-#define CR4_PGE_MASK (1ULL << 7)
-#define CR4_VMXE_MASK (1ULL << 13)
-
 #define KVM_GUEST_CR0_MASK \
 	(X86_CR0_PG | X86_CR0_PE | X86_CR0_WP | X86_CR0_NE \
 	 | X86_CR0_NW | X86_CR0_CD)
@@ -36,9 +30,9 @@
 	(X86_CR0_PG | X86_CR0_PE | X86_CR0_WP | X86_CR0_NE | X86_CR0_TS \
 	 | X86_CR0_MP)
 #define KVM_GUEST_CR4_MASK \
-	(CR4_PSE_MASK | CR4_PAE_MASK | CR4_PGE_MASK | CR4_VMXE_MASK | CR4_VME_MASK)
-#define KVM_PMODE_VM_CR4_ALWAYS_ON (CR4_VMXE_MASK | CR4_PAE_MASK)
-#define KVM_RMODE_VM_CR4_ALWAYS_ON (CR4_VMXE_MASK | CR4_PAE_MASK | CR4_VME_MASK)
+	(X86_CR4_VME | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_PGE | X86_CR4_VMXE)
+#define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE)
+#define KVM_RMODE_VM_CR4_ALWAYS_ON (X86_CR4_VME | X86_CR4_PAE | X86_CR4_VMXE)
 
 #define INVALID_PAGE (~(hpa_t)0)
 #define UNMAPPED_GVA (~(gpa_t)0)
@@ -645,12 +639,12 @@
 
 static inline int is_pae(struct kvm_vcpu *vcpu)
 {
-	return vcpu->cr4 & CR4_PAE_MASK;
+	return vcpu->cr4 & X86_CR4_PAE;
 }
 
 static inline int is_pse(struct kvm_vcpu *vcpu)
 {
-	return vcpu->cr4 & CR4_PSE_MASK;
+	return vcpu->cr4 & X86_CR4_PSE;
 }
 
 static inline int is_paging(struct kvm_vcpu *vcpu)