KVM: VMX: cleanup vmx_set_cr0().

When calculating hw_cr0 teh current code masks bits that should be always
on and re-adds them back immediately after. Cleanup the code by masking
only those bits that should be dropped from hw_cr0. This allow us to
get rid of some defines.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/vmx.c

@@ -95,12 +95,8 @@ module_param(enable_apicv_reg_vid, bool, S_IRUGO);
 static bool __read_mostly nested = 0;
 module_param(nested, bool, S_IRUGO);
 
-#define KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST				\
-	(X86_CR0_WP | X86_CR0_NE | X86_CR0_NW | X86_CR0_CD)
-#define KVM_GUEST_CR0_MASK						\
-	(KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
-#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST				\
-	(X86_CR0_WP | X86_CR0_NE)
+#define KVM_GUEST_CR0_MASK (X86_CR0_NW | X86_CR0_CD)
+#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST (X86_CR0_WP | X86_CR0_NE)
 #define KVM_VM_CR0_ALWAYS_ON						\
 	(KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
 #define KVM_CR4_GUEST_OWNED_BITS				      \
@@ -3137,11 +3133,11 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	unsigned long hw_cr0;
 
+	hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK);
 	if (enable_unrestricted_guest)
-		hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST)
-			| KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST;
+		hw_cr0 |= KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST;
 	else {
-		hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK) | KVM_VM_CR0_ALWAYS_ON;
+		hw_cr0 |= KVM_VM_CR0_ALWAYS_ON;
 
 		if (vmx->rmode.vm86_active && (cr0 & X86_CR0_PE))
 			enter_pmode(vcpu);