KVM: Pass kvm_init()'s opaque param to additional arch funcs

Pass @opaque to kvm_arch_hardware_setup() and
kvm_arch_check_processor_compat() to allow architecture specific code to
reference @opaque without having to stash it away in a temporary global
variable.  This will enable x86 to separate its vendor specific callback
ops, which are passed via @opaque, into "init" and "runtime" ops without
having to stash away the "init" ops.

No functional change intended.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Cornelia Huck <cohuck@redhat.com> #s390
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321202603.19355-2-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

virt/kvm/arm/arm.c

@@ -64,12 +64,12 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
 }
 
-int kvm_arch_hardware_setup(void)
+int kvm_arch_hardware_setup(void *opaque)
 {
 	return 0;
 }
 
-int kvm_arch_check_processor_compat(void)
+int kvm_arch_check_processor_compat(void *opaque)
 {
 	return 0;
 }

virt/kvm/kvm_main.c

@@ -4648,14 +4648,22 @@ struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
         return &kvm_running_vcpu;
 }
 
-static void check_processor_compat(void *rtn)
+struct kvm_cpu_compat_check {
+	void *opaque;
+	int *ret;
+};
+
+static void check_processor_compat(void *data)
 {
-	*(int *)rtn = kvm_arch_check_processor_compat();
+	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;
 
@@ -4679,12 +4687,14 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 		goto out_free_0;
 	}
 
-	r = kvm_arch_hardware_setup();
+	r = kvm_arch_hardware_setup(opaque);
 	if (r < 0)
 		goto out_free_1;
 
+	c.ret = &r;
+	c.opaque = opaque;
 	for_each_online_cpu(cpu) {
-		smp_call_function_single(cpu, check_processor_compat, &r, 1);
+		smp_call_function_single(cpu, check_processor_compat, &c, 1);
 		if (r < 0)
 			goto out_free_2;
 	}