x86/virt: KVM: Open code cpu_has_svm() into kvm_is_svm_supported()

Fold the guts of cpu_has_svm() into kvm_is_svm_supported(), its sole
remaining user.

No functional change intended.

Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230721201859.2307736-14-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

arch/x86/include/asm/virtext.h

@@ -22,35 +22,7 @@
 /*
  * SVM functions:
  */
-
-/** Check if the CPU has SVM support
- *
- * You can use the 'msg' arg to get a message describing the problem,
- * if the function returns zero. Simply pass NULL if you are not interested
- * on the messages; gcc should take care of not generating code for
- * the messages on this case.
- */
-static inline int cpu_has_svm(const char **msg)
-{
-	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
-	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) {
-		if (msg)
-			*msg = "not amd or hygon";
-		return 0;
-	}
-
-	if (!boot_cpu_has(X86_FEATURE_SVM)) {
-		if (msg)
-			*msg = "svm not available";
-		return 0;
-	}
-	return 1;
-}
-
-
 /** Disable SVM on the current CPU
- *
- * You should call this only if cpu_has_svm() returned true.
  */
 static inline void cpu_svm_disable(void)
 {

arch/x86/kvm/svm/svm.c

@@ -521,11 +521,16 @@ static void svm_init_osvw(struct kvm_vcpu *vcpu)
 static bool kvm_is_svm_supported(void)
 {
 	int cpu = raw_smp_processor_id();
-	const char *msg;
 	u64 vm_cr;
 
-	if (!cpu_has_svm(&msg)) {
-		pr_err("SVM not supported by CPU %d, %s\n", cpu, msg);
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) {
+		pr_err("CPU %d isn't AMD or Hygon\n", cpu);
+		return false;
+	}
+
+	if (!boot_cpu_has(X86_FEATURE_SVM)) {
+		pr_err("SVM not supported by CPU %d\n", cpu);
 		return false;
 	}