machine: make MemoryHotplugState accessible via the machine

Let's allow to query the MemoryHotplugState directly from the machine.
If the pointer is NULL, the machine does not support memory devices. If
the pointer is !NULL, the machine supports memory devices and the
data structure contains information about the applicable physical
guest address space region.

This allows us to generically detect if a certain machine has support
for memory devices, and to generically manage it (find free address
range, plug/unplug a memory region).

We will rename "MemoryHotplugState" to something more meaningful
("DeviceMemory") after we completed factoring out the pc-dimm code into
MemoryDevice code.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180423165126.15441-3-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
[ehabkost: rebased series, solved conflicts at spapr.c]
[ehabkost: squashed fix to use g_malloc0()]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

2 files changed, 21 insertions, 16 deletions

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 624e955..b1eddeb 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -2411,7 +2411,7 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
      * providing _PXM method if necessary.
      */
     if (hotplugabble_address_space_size) {
-        build_srat_hotpluggable_memory(table_data, pcms->hotplug_memory.base,
+        build_srat_hotpluggable_memory(table_data, machine->device_memory->base,
                                        hotplugabble_address_space_size,
                                        pcms->numa_nodes - 1);
     }
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index b297a5d..0aa7885 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1371,6 +1371,9 @@ void pc_memory_init(PCMachineState *pcms,
         exit(EXIT_FAILURE);
     }
 
+    /* always allocate the device memory information */
+    machine->device_memory = g_malloc0(sizeof(*machine->device_memory));
+
     /* initialize hotplug memory address space */
     if (pcmc->has_reserved_memory &&
         (machine->ram_size < machine->maxram_size)) {
@@ -1390,7 +1393,7 @@ void pc_memory_init(PCMachineState *pcms,
             exit(EXIT_FAILURE);
         }
 
-        pcms->hotplug_memory.base =
+        machine->device_memory->base =
             ROUND_UP(0x100000000ULL + pcms->above_4g_mem_size, 1ULL << 30);
 
         if (pcmc->enforce_aligned_dimm) {
@@ -1398,17 +1401,17 @@ void pc_memory_init(PCMachineState *pcms,
             hotplug_mem_size += (1ULL << 30) * machine->ram_slots;
         }
 
-        if ((pcms->hotplug_memory.base + hotplug_mem_size) <
+        if ((machine->device_memory->base + hotplug_mem_size) <
             hotplug_mem_size) {
             error_report("unsupported amount of maximum memory: " RAM_ADDR_FMT,
                          machine->maxram_size);
             exit(EXIT_FAILURE);
         }
 
-        memory_region_init(&pcms->hotplug_memory.mr, OBJECT(pcms),
+        memory_region_init(&machine->device_memory->mr, OBJECT(pcms),
                            "hotplug-memory", hotplug_mem_size);
-        memory_region_add_subregion(system_memory, pcms->hotplug_memory.base,
-                                    &pcms->hotplug_memory.mr);
+        memory_region_add_subregion(system_memory, machine->device_memory->base,
+                                    &machine->device_memory->mr);
     }
 
     /* Initialize PC system firmware */
@@ -1429,13 +1432,13 @@ void pc_memory_init(PCMachineState *pcms,
 
     rom_set_fw(fw_cfg);
 
-    if (pcmc->has_reserved_memory && pcms->hotplug_memory.base) {
+    if (pcmc->has_reserved_memory && machine->device_memory->base) {
         uint64_t *val = g_malloc(sizeof(*val));
         PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
-        uint64_t res_mem_end = pcms->hotplug_memory.base;
+        uint64_t res_mem_end = machine->device_memory->base;
 
         if (!pcmc->broken_reserved_end) {
-            res_mem_end += memory_region_size(&pcms->hotplug_memory.mr);
+            res_mem_end += memory_region_size(&machine->device_memory->mr);
         }
         *val = cpu_to_le64(ROUND_UP(res_mem_end, 0x1ULL << 30));
         fw_cfg_add_file(fw_cfg, "etc/reserved-memory-end", val, sizeof(*val));
@@ -1462,12 +1465,13 @@ uint64_t pc_pci_hole64_start(void)
 {
     PCMachineState *pcms = PC_MACHINE(qdev_get_machine());
     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
+    MachineState *ms = MACHINE(pcms);
     uint64_t hole64_start = 0;
 
-    if (pcmc->has_reserved_memory && pcms->hotplug_memory.base) {
-        hole64_start = pcms->hotplug_memory.base;
+    if (pcmc->has_reserved_memory && ms->device_memory->base) {
+        hole64_start = ms->device_memory->base;
         if (!pcmc->broken_reserved_end) {
-            hole64_start += memory_region_size(&pcms->hotplug_memory.mr);
+            hole64_start += memory_region_size(&ms->device_memory->mr);
         }
     } else {
         hole64_start = 0x100000000ULL + pcms->above_4g_mem_size;
@@ -1711,7 +1715,8 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
         goto out;
     }
 
-    pc_dimm_memory_plug(dev, &pcms->hotplug_memory, mr, align, &local_err);
+    pc_dimm_memory_plug(dev, MACHINE(pcms)->device_memory, mr, align,
+                        &local_err);
     if (local_err) {
         goto out;
     }
@@ -1779,7 +1784,7 @@ static void pc_dimm_unplug(HotplugHandler *hotplug_dev,
         goto out;
     }
 
-    pc_dimm_memory_unplug(dev, &pcms->hotplug_memory, mr);
+    pc_dimm_memory_unplug(dev, MACHINE(pcms)->device_memory, mr);
     object_unparent(OBJECT(dev));
 
  out:
@@ -2072,8 +2077,8 @@ pc_machine_get_hotplug_memory_region_size(Object *obj, Visitor *v,
                                           const char *name, void *opaque,
                                           Error **errp)
 {
-    PCMachineState *pcms = PC_MACHINE(obj);
-    int64_t value = memory_region_size(&pcms->hotplug_memory.mr);
+    MachineState *ms = MACHINE(obj);
+    int64_t value = memory_region_size(&ms->device_memory->mr);
 
     visit_type_int(v, name, &value, errp);
 }