kvm: don't register smram_listener when smm is off

If the user set disable smm by '-machine smm=off', we
should not register smram_listener so that we can
avoid waster memory in kvm since the added sencond
address space.

Meanwhile we should assign value of the global kvm_state
before invoking the kvm_arch_init(), because
pc_machine_is_smm_enabled() may use it by kvm_has_mm().

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Message-Id: <1496316915-121196-1-git-send-email-arei.gonglei@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

kvm-all.c

@@ -1748,6 +1748,8 @@ static int kvm_init(MachineState *ms)
     kvm_ioeventfd_any_length_allowed =
         (kvm_check_extension(s, KVM_CAP_IOEVENTFD_ANY_LENGTH) > 0);
 
+    kvm_state = s;
+
     ret = kvm_arch_init(ms, s);
     if (ret < 0) {
         goto err;
@@ -1757,8 +1759,6 @@ static int kvm_init(MachineState *ms)
         kvm_irqchip_create(ms, s);
     }
 
-    kvm_state = s;
-
     if (kvm_eventfds_allowed) {
         s->memory_listener.listener.eventfd_add = kvm_mem_ioeventfd_add;
         s->memory_listener.listener.eventfd_del = kvm_mem_ioeventfd_del;

target/i386/kvm.c

@@ -1255,7 +1255,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
         }
     }
 
-    if (kvm_check_extension(s, KVM_CAP_X86_SMM)) {
+    if (kvm_check_extension(s, KVM_CAP_X86_SMM) &&
+        object_dynamic_cast(OBJECT(ms), TYPE_PC_MACHINE) &&
+        pc_machine_is_smm_enabled(PC_MACHINE(ms))) {
         smram_machine_done.notify = register_smram_listener;
         qemu_add_machine_init_done_notifier(&smram_machine_done);
     }