KVM: VMX: Add and use X86_CR4_PDPTR_BITS when !enable_ept

In set_cr4_guest_host_mask(), all cr4 pdptr bits are already set to be
intercepted in an unclear way.

Add X86_CR4_PDPTR_BITS to make it clear and self-documented.

No functionality changed.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211108124407.12187-6-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/kvm_cache_regs.h

@@ -10,6 +10,7 @@
 	 | X86_CR4_OSXMMEXCPT | X86_CR4_PGE | X86_CR4_TSD | X86_CR4_FSGSBASE)
 
 #define X86_CR4_TLBFLUSH_BITS (X86_CR4_PGE | X86_CR4_PCIDE | X86_CR4_PAE | X86_CR4_SMEP)
+#define X86_CR4_PDPTR_BITS    (X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_SMEP)
 
 #define BUILD_KVM_GPR_ACCESSORS(lname, uname)				      \
 static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\

arch/x86/kvm/vmx/vmx.c

@@ -4044,8 +4044,10 @@ void set_cr4_guest_host_mask(struct vcpu_vmx *vmx)
 
 	vcpu->arch.cr4_guest_owned_bits = KVM_POSSIBLE_CR4_GUEST_BITS &
 					  ~vcpu->arch.cr4_guest_rsvd_bits;
-	if (!enable_ept)
+	if (!enable_ept) {
 		vcpu->arch.cr4_guest_owned_bits &= ~X86_CR4_TLBFLUSH_BITS;
+		vcpu->arch.cr4_guest_owned_bits &= ~X86_CR4_PDPTR_BITS;
+	}
 	if (is_guest_mode(&vmx->vcpu))
 		vcpu->arch.cr4_guest_owned_bits &=
 			~get_vmcs12(vcpu)->cr4_guest_host_mask;

arch/x86/kvm/x86.c

@@ -1051,8 +1051,6 @@ EXPORT_SYMBOL_GPL(kvm_post_set_cr4);
 int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 {
 	unsigned long old_cr4 = kvm_read_cr4(vcpu);
-	unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE |
-				   X86_CR4_SMEP;
 
 	if (!kvm_is_valid_cr4(vcpu, cr4))
 		return 1;
@@ -1063,7 +1061,7 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 		if ((cr4 ^ old_cr4) & X86_CR4_LA57)
 			return 1;
 	} else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE)
-		   && ((cr4 ^ old_cr4) & pdptr_bits)
+		   && ((cr4 ^ old_cr4) & X86_CR4_PDPTR_BITS)
 		   && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
 				   kvm_read_cr3(vcpu)))
 		return 1;