sgx-epc: Add the fill_device_info() callback support

Since there is no fill_device_info() callback support, and when we
execute "info memory-devices" command in the monitor, the segfault
will be found.

This patch will add this callback support and "info memory-devices"
will show sgx epc memory exposed to guest. The result as below:

qemu) info memory-devices
Memory device [sgx-epc]: ""
  memaddr: 0x180000000
  size: 29360128
  memdev: /objects/mem1
Memory device [sgx-epc]: ""
  memaddr: 0x181c00000
  size: 10485760
  memdev: /objects/mem2

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20210719112136.57018-33-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/i386/sgx-epc.c

@@ -133,7 +133,16 @@ static MemoryRegion *sgx_epc_md_get_memory_region(MemoryDeviceState *md,
 static void sgx_epc_md_fill_device_info(const MemoryDeviceState *md,
                                         MemoryDeviceInfo *info)
 {
-    /* TODO */
+    SgxEPCDeviceInfo *se = g_new0(SgxEPCDeviceInfo, 1);
+    SGXEPCDevice *epc = SGX_EPC(md);
+
+    se->memaddr = epc->addr;
+    se->size = object_property_get_uint(OBJECT(epc), SGX_EPC_SIZE_PROP,
+                                        NULL);
+    se->memdev = object_get_canonical_path(OBJECT(epc->hostmem));
+
+    info->u.sgx_epc.data = se;
+    info->type = MEMORY_DEVICE_INFO_KIND_SGX_EPC;
 }
 
 static void sgx_epc_class_init(ObjectClass *oc, void *data)

monitor/hmp-cmds.c

@@ -1823,6 +1823,7 @@ void hmp_info_memory_devices(Monitor *mon, const QDict *qdict)
     VirtioMEMDeviceInfo *vmi;
     MemoryDeviceInfo *value;
     PCDIMMDeviceInfo *di;
+    SgxEPCDeviceInfo *se;
 
     for (info = info_list; info; info = info->next) {
         value = info->value;
@@ -1870,6 +1871,15 @@ void hmp_info_memory_devices(Monitor *mon, const QDict *qdict)
                                vmi->block_size);
                 monitor_printf(mon, "  memdev: %s\n", vmi->memdev);
                 break;
+            case MEMORY_DEVICE_INFO_KIND_SGX_EPC:
+                se = value->u.sgx_epc.data;
+                monitor_printf(mon, "Memory device [%s]: \"%s\"\n",
+                               MemoryDeviceInfoKind_str(value->type),
+                               se->id ? se->id : "");
+                monitor_printf(mon, "  memaddr: 0x%" PRIx64 "\n", se->memaddr);
+                monitor_printf(mon, "  size: %" PRIu64 "\n", se->size);
+                monitor_printf(mon, "  memdev: %s\n", se->memdev);
+                break;
             default:
                 g_assert_not_reached();
             }

qapi/machine.json

@@ -1194,13 +1194,36 @@
           }
 }
 
+##
+# @SgxEPCDeviceInfo:
+#
+# Sgx EPC state information
+#
+# @id: device's ID
+#
+# @memaddr: physical address in memory, where device is mapped
+#
+# @size: size of memory that the device provides
+#
+# @memdev: memory backend linked with device
+#
+# Since: 6.2
+##
+{ 'struct': 'SgxEPCDeviceInfo',
+  'data': { '*id': 'str',
+            'memaddr': 'size',
+            'size': 'size',
+            'memdev': 'str'
+          }
+}
+
 ##
 # @MemoryDeviceInfoKind:
 #
 # Since: 2.1
 ##
 { 'enum': 'MemoryDeviceInfoKind',
-  'data': [ 'dimm', 'nvdimm', 'virtio-pmem', 'virtio-mem' ] }
+  'data': [ 'dimm', 'nvdimm', 'virtio-pmem', 'virtio-mem', 'sgx-epc' ] }
 
 ##
 # @PCDIMMDeviceInfoWrapper:
@@ -1225,13 +1248,22 @@
 ##
 { 'struct': 'VirtioMEMDeviceInfoWrapper',
   'data': { 'data': 'VirtioMEMDeviceInfo' } }
+
+##
+# @SgxEPCDeviceInfoWrapper:
+#
+# Since: 6.2
+##
+{ 'struct': 'SgxEPCDeviceInfoWrapper',
+  'data': { 'data': 'SgxEPCDeviceInfo' } }
+
 ##
 # @MemoryDeviceInfo:
 #
 # Union containing information about a memory device
 #
 # nvdimm is included since 2.12. virtio-pmem is included since 4.1.
-# virtio-mem is included since 5.1.
+# virtio-mem is included since 5.1. sgx-epc is included since 6.2.
 #
 # Since: 2.1
 ##
@@ -1241,7 +1273,8 @@
   'data': { 'dimm': 'PCDIMMDeviceInfoWrapper',
             'nvdimm': 'PCDIMMDeviceInfoWrapper',
             'virtio-pmem': 'VirtioPMEMDeviceInfoWrapper',
-            'virtio-mem': 'VirtioMEMDeviceInfoWrapper'
+            'virtio-mem': 'VirtioMEMDeviceInfoWrapper',
+            'sgx-epc': 'SgxEPCDeviceInfoWrapper'
           }
 }