[PULL,v2,06/15] pc: align DIMM's address/size by backend's alignment value

diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 7c3731f..9d85b89 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -24,6 +24,8 @@ 
  * address space begins.
  * @hotplug_memory: hotplug memory addess space container
  * @acpi_dev: link to ACPI PM device that performs ACPI hotplug handling
+ * @enforce_aligned_dimm: check that DIMM's address/size is aligned by
+ *                        backend's alignment value if provided
  */
 struct PCMachineState {
     /*< private >*/
@@ -38,12 +40,14 @@  struct PCMachineState {
 
     uint64_t max_ram_below_4g;
     bool vmport;
+    bool enforce_aligned_dimm;
 };
 
 #define PC_MACHINE_ACPI_DEVICE_PROP "acpi-device"
 #define PC_MACHINE_MEMHP_REGION_SIZE "hotplug-memory-region-size"
 #define PC_MACHINE_MAX_RAM_BELOW_4G "max-ram-below-4g"
 #define PC_MACHINE_VMPORT           "vmport"
+#define PC_MACHINE_ENFORCE_ALIGNED_DIMM "enforce-aligned-dimm"
 
 /**
  * PCMachineClass:
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 33928b9..021ec44 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1564,6 +1564,10 @@  static void pc_dimm_plug(HotplugHandler *hotplug_dev,
         goto out;
     }
 
+    if (memory_region_get_alignment(mr) && pcms->enforce_aligned_dimm) {
+        align = memory_region_get_alignment(mr);
+    }
+
     addr = pc_dimm_get_free_addr(pcms->hotplug_memory_base,
                                  memory_region_size(&pcms->hotplug_memory),
                                  !addr ? NULL : &addr, align,
@@ -1732,6 +1736,13 @@  static void pc_machine_set_vmport(Object *obj, bool value, Error **errp)
     pcms->vmport = value;
 }
 
+static bool pc_machine_get_aligned_dimm(Object *obj, Error **errp)
+{
+    PCMachineState *pcms = PC_MACHINE(obj);
+
+    return pcms->enforce_aligned_dimm;
+}
+
 static void pc_machine_initfn(Object *obj)
 {
     PCMachineState *pcms = PC_MACHINE(obj);
@@ -1744,11 +1755,17 @@  static void pc_machine_initfn(Object *obj)
                         pc_machine_get_max_ram_below_4g,
                         pc_machine_set_max_ram_below_4g,
                         NULL, NULL, NULL);
+
     pcms->vmport = !xen_enabled();
     object_property_add_bool(obj, PC_MACHINE_VMPORT,
                              pc_machine_get_vmport,
                              pc_machine_set_vmport,
                              NULL);
+
+    pcms->enforce_aligned_dimm = true;
+    object_property_add_bool(obj, PC_MACHINE_ENFORCE_ALIGNED_DIMM,
+                             pc_machine_get_aligned_dimm,
+                             NULL, NULL);
 }
 
 static void pc_machine_class_init(ObjectClass *oc, void *data)
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 7bb97a4..741dffd 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -305,10 +305,12 @@  static void pc_init_pci(MachineState *machine)
 
 static void pc_compat_2_1(MachineState *machine)
 {
+    PCMachineState *pcms = PC_MACHINE(machine);
     smbios_uuid_encoded = false;
     x86_cpu_compat_set_features("coreduo", FEAT_1_ECX, CPUID_EXT_VMX, 0);
     x86_cpu_compat_set_features("core2duo", FEAT_1_ECX, CPUID_EXT_VMX, 0);
     x86_cpu_compat_kvm_no_autodisable(FEAT_8000_0001_ECX, CPUID_EXT3_SVM);
+    pcms->enforce_aligned_dimm = false;
 }
 
 static void pc_compat_2_0(MachineState *machine)
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 598e679..e9ba1a2 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -284,6 +284,9 @@  static void pc_q35_init(MachineState *machine)
 
 static void pc_compat_2_1(MachineState *machine)
 {
+    PCMachineState *pcms = PC_MACHINE(machine);
+
+    pcms->enforce_aligned_dimm = false;
     smbios_uuid_encoded = false;
     x86_cpu_compat_set_features("coreduo", FEAT_1_ECX, CPUID_EXT_VMX, 0);
     x86_cpu_compat_set_features("core2duo", FEAT_1_ECX, CPUID_EXT_VMX, 0);