target-i386: use memory API to implement SMRAM

Remove cpu_smm_register and cpu_smm_update.  Instead, each CPU
address space gets an extra region which is an alias of
/machine/smram.  This extra region is enabled or disabled
as the CPU enters/exits SMM.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 31 insertions, 2 deletions

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 051abc92cb..4e7cdaaaa5 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2751,6 +2751,21 @@ static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
     object_property_set_bool(OBJECT(cpu->apic_state), true, "realized",
                              errp);
 }
+
+static void x86_cpu_machine_done(Notifier *n, void *unused)
+{
+    X86CPU *cpu = container_of(n, X86CPU, machine_done);
+    MemoryRegion *smram =
+        (MemoryRegion *) object_resolve_path("/machine/smram", NULL);
+
+    if (smram) {
+        cpu->smram = g_new(MemoryRegion, 1);
+        memory_region_init_alias(cpu->smram, OBJECT(cpu), "smram",
+                                 smram, 0, 1ull << 32);
+        memory_region_set_enabled(cpu->smram, false);
+        memory_region_add_subregion_overlap(cpu->cpu_as_root, 0, cpu->smram, 1);
+    }
+}
 #else
 static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
 {
@@ -2815,12 +2830,26 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
 
 #ifndef CONFIG_USER_ONLY
     if (tcg_enabled()) {
+        cpu->cpu_as_mem = g_new(MemoryRegion, 1);
         cpu->cpu_as_root = g_new(MemoryRegion, 1);
         cs->as = g_new(AddressSpace, 1);
-        memory_region_init_alias(cpu->cpu_as_root, OBJECT(cpu), "memory",
-                                 get_system_memory(), 0, ~0ull);
+
+        /* Outer container... */
+        memory_region_init(cpu->cpu_as_root, OBJECT(cpu), "memory", ~0ull);
         memory_region_set_enabled(cpu->cpu_as_root, true);
+
+        /* ... with two regions inside: normal system memory with low
+         * priority, and...
+         */
+        memory_region_init_alias(cpu->cpu_as_mem, OBJECT(cpu), "memory",
+                                 get_system_memory(), 0, ~0ull);
+        memory_region_add_subregion_overlap(cpu->cpu_as_root, 0, cpu->cpu_as_mem, 0);
+        memory_region_set_enabled(cpu->cpu_as_mem, true);
         address_space_init(cs->as, cpu->cpu_as_root, "CPU");
+
+        /* ... SMRAM with higher priority, linked from /machine/smram.  */
+        cpu->machine_done.notify = x86_cpu_machine_done;
+        qemu_add_machine_init_done_notifier(&cpu->machine_done);
     }
 #endif