KVM: x86: Remove kvm_vcpu_is_illegal_gpa()

Remove kvm_vcpu_is_illegal_gpa() and use !kvm_vcpu_is_legal_gpa() instead.
The "illegal" helper actually predates the "legal" helper, the only reason
the "illegal" variant wasn't removed by commit 4bda0e9 ("KVM: x86:
Add a helper to check for a legal GPA") was to avoid code churn.  Now that
CR3 has a dedicated helper, there are fewer callers, and so the code churn
isn't that much of a deterrent.

No functional change intended.

Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
Link: https://lore.kernel.org/r/20230913124227.12574-8-binbin.wu@linux.intel.com
[sean: provide a bit of history in the changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: Binbin Wu

arch/x86/kvm/cpuid.h

@@ -47,11 +47,6 @@ static inline bool kvm_vcpu_is_legal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
 	return !(gpa & vcpu->arch.reserved_gpa_bits);
 }
 
-static inline bool kvm_vcpu_is_illegal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
-{
-	return !kvm_vcpu_is_legal_gpa(vcpu, gpa);
-}
-
 static inline bool kvm_vcpu_is_legal_aligned_gpa(struct kvm_vcpu *vcpu,
 						 gpa_t gpa, gpa_t alignment)
 {

arch/x86/kvm/vmx/nested.c

@@ -2717,7 +2717,7 @@ static bool nested_vmx_check_eptp(struct kvm_vcpu *vcpu, u64 new_eptp)
 	}
 
 	/* Reserved bits should not be set */
-	if (CC(kvm_vcpu_is_illegal_gpa(vcpu, new_eptp) || ((new_eptp >> 7) & 0x1f)))
+	if (CC(!kvm_vcpu_is_legal_gpa(vcpu, new_eptp) || ((new_eptp >> 7) & 0x1f)))
 		return false;
 
 	/* AD, if set, should be supported */

arch/x86/kvm/vmx/vmx.c

@@ -5782,7 +5782,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 	 * would also use advanced VM-exit information for EPT violations to
 	 * reconstruct the page fault error code.
 	 */
-	if (unlikely(allow_smaller_maxphyaddr && kvm_vcpu_is_illegal_gpa(vcpu, gpa)))
+	if (unlikely(allow_smaller_maxphyaddr && !kvm_vcpu_is_legal_gpa(vcpu, gpa)))
 		return kvm_emulate_instruction(vcpu, 0);
 
 	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);