KVM: Drop kvm_arch_check_processor_compat() hook

Drop kvm_arch_check_processor_compat() and its support code now that all
architecture implementations are nops.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Eric Farman <farman@linux.ibm.com>	# s390
Acked-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Message-Id: <20221130230934.1014142-33-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/arm64/kvm/arm.c

@@ -63,11 +63,6 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
 }
 
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 			    struct kvm_enable_cap *cap)
 {
@@ -2285,7 +2280,7 @@ static __init int kvm_arm_init(void)
 	 * FIXME: Do something reasonable if kvm_init() fails after pKVM
 	 * hypervisor protection is finalized.
 	 */
-	err = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	err = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 	if (err)
 		goto out_subs;
 

arch/mips/kvm/mips.c

@@ -135,11 +135,6 @@ void kvm_arch_hardware_disable(void)
 	kvm_mips_callbacks->hardware_disable();
 }
 
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 extern void kvm_init_loongson_ipi(struct kvm *kvm);
 
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
@@ -1636,7 +1631,7 @@ static int __init kvm_mips_init(void)
 
 	register_die_notifier(&kvm_mips_csr_die_notifier);
 
-	ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	ret = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 	if (ret) {
 		unregister_die_notifier(&kvm_mips_csr_die_notifier);
 		return ret;

arch/powerpc/kvm/book3s.c

@@ -1052,7 +1052,7 @@ static int kvmppc_book3s_init(void)
 {
 	int r;
 
-	r = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	r = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 	if (r)
 		return r;
 #ifdef CONFIG_KVM_BOOK3S_32_HANDLER

arch/powerpc/kvm/e500.c

@@ -531,7 +531,7 @@ static int __init kvmppc_e500_init(void)
 	flush_icache_range(kvmppc_booke_handlers, kvmppc_booke_handlers +
 			   ivor[max_ivor] + handler_len);
 
-	r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
+	r = kvm_init(sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
 	if (r)
 		goto err_out;
 	kvm_ops_e500.owner = THIS_MODULE;

arch/powerpc/kvm/e500mc.c

@@ -404,7 +404,7 @@ static int __init kvmppc_e500mc_init(void)
 	 */
 	kvmppc_init_lpid(KVMPPC_NR_LPIDS/threads_per_core);
 
-	r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
+	r = kvm_init(sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
 	if (r)
 		goto err_out;
 	kvm_ops_e500mc.owner = THIS_MODULE;

arch/powerpc/kvm/powerpc.c

@@ -440,11 +440,6 @@ int kvm_arch_hardware_enable(void)
 	return 0;
 }
 
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
 	struct kvmppc_ops *kvm_ops = NULL;

arch/riscv/kvm/main.c

@@ -20,11 +20,6 @@ long kvm_arch_dev_ioctl(struct file *filp,
 	return -EINVAL;
 }
 
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 int kvm_arch_hardware_enable(void)
 {
 	unsigned long hideleg, hedeleg;
@@ -110,7 +105,7 @@ static int __init riscv_kvm_init(void)
 
 	kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits());
 
-	return kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 }
 module_init(riscv_kvm_init);
 

arch/s390/kvm/kvm-s390.c

@@ -262,11 +262,6 @@ int kvm_arch_hardware_enable(void)
 	return 0;
 }
 
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 /* forward declarations */
 static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start,
 			      unsigned long end);
@@ -5716,7 +5711,7 @@ static int __init kvm_s390_init(void)
 	if (r)
 		return r;
 
-	r = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	r = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 	if (r) {
 		__kvm_s390_exit();
 		return r;

arch/x86/kvm/svm/svm.c

@@ -5109,8 +5109,8 @@ static int __init svm_init(void)
 	 * Common KVM initialization _must_ come last, after this, /dev/kvm is
 	 * exposed to userspace!
 	 */
-	r = kvm_init(NULL, sizeof(struct vcpu_svm),
-		     __alignof__(struct vcpu_svm), THIS_MODULE);
+	r = kvm_init(sizeof(struct vcpu_svm), __alignof__(struct vcpu_svm),
+		     THIS_MODULE);
 	if (r)
 		goto err_kvm_init;
 

arch/x86/kvm/vmx/vmx.c

@@ -8635,8 +8635,8 @@ static int __init vmx_init(void)
 	 * Common KVM initialization _must_ come last, after this, /dev/kvm is
 	 * exposed to userspace!
 	 */
-	r = kvm_init(NULL, sizeof(struct vcpu_vmx),
-		     __alignof__(struct vcpu_vmx), THIS_MODULE);
+	r = kvm_init(sizeof(struct vcpu_vmx), __alignof__(struct vcpu_vmx),
+		     THIS_MODULE);
 	if (r)
 		goto err_kvm_init;
 

arch/x86/kvm/x86.c

@@ -12084,11 +12084,6 @@ void kvm_arch_hardware_disable(void)
 	drop_user_return_notifiers();
 }
 
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
 {
 	return vcpu->kvm->arch.bsp_vcpu_id == vcpu->vcpu_id;

include/linux/kvm_host.h

@@ -956,8 +956,7 @@ static inline void kvm_irqfd_exit(void)
 {
 }
 #endif
-int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
-		  struct module *module);
+int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module);
 void kvm_exit(void);
 
 void kvm_get_kvm(struct kvm *kvm);
@@ -1444,7 +1443,6 @@ static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {}
 
 int kvm_arch_hardware_enable(void);
 void kvm_arch_hardware_disable(void);
-int kvm_arch_check_processor_compat(void *opaque);
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu);
 bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu);
 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu);

virt/kvm/kvm_main.c

@@ -5902,36 +5902,14 @@ void kvm_unregister_perf_callbacks(void)
 }
 #endif
 
-struct kvm_cpu_compat_check {
-	void *opaque;
-	int *ret;
-};
-
-static void check_processor_compat(void *data)
+int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
 {
-	struct kvm_cpu_compat_check *c = data;
-
-	*c->ret = kvm_arch_check_processor_compat(c->opaque);
-}
-
-int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
-		  struct module *module)
-{
-	struct kvm_cpu_compat_check c;
 	int r;
 	int cpu;
 
 	if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL))
 		return -ENOMEM;
 
-	c.ret = &r;
-	c.opaque = opaque;
-	for_each_online_cpu(cpu) {
-		smp_call_function_single(cpu, check_processor_compat, &c, 1);
-		if (r < 0)
-			goto out_free_2;
-	}
-
 	r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting",
 				      kvm_starting_cpu, kvm_dying_cpu);
 	if (r)