qemu: conf: Add support for memory device cold(un)plug

Add a few helpers that allow to operate with memory device definitions
on the domain config and use them to implement memory device coldplug in
the qemu driver.

src/conf/domain_conf.c

@@ -12812,6 +12812,106 @@ virDomainRNGRemove(virDomainDefPtr def,
 }
 
 
+static int
+virDomainMemoryFindByDefInternal(virDomainDefPtr def,
+                                 virDomainMemoryDefPtr mem,
+                                 bool allowAddressFallback)
+{
+    size_t i;
+
+    for (i = 0; i < def->nmems; i++) {
+        virDomainMemoryDefPtr tmp = def->mems[i];
+
+        /* address, if present */
+        if (allowAddressFallback) {
+            if (tmp->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE)
+                continue;
+        } else {
+            if (mem->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE &&
+                !virDomainDeviceInfoAddressIsEqual(&tmp->info, &mem->info))
+                continue;
+        }
+
+        /* alias, if present */
+        if (mem->info.alias &&
+            STRNEQ_NULLABLE(tmp->info.alias, mem->info.alias))
+            continue;
+
+        /* target info -> always present */
+        if (tmp->model != mem->model ||
+            tmp->targetNode != mem->targetNode ||
+            tmp->size != mem->size)
+            continue;
+
+        /* source stuff -> match with device */
+        if (tmp->pagesize != mem->pagesize)
+            continue;
+
+        if (!virBitmapEqual(tmp->sourceNodes, mem->sourceNodes))
+            continue;
+
+        break;
+    }
+
+    if (i == def->nmems)
+        return -1;
+
+    return i;
+}
+
+
+int
+virDomainMemoryFindByDef(virDomainDefPtr def,
+                         virDomainMemoryDefPtr mem)
+{
+    return virDomainMemoryFindByDefInternal(def, mem, false);
+}
+
+
+int
+virDomainMemoryFindInactiveByDef(virDomainDefPtr def,
+                                 virDomainMemoryDefPtr mem)
+{
+    int ret;
+
+    if ((ret = virDomainMemoryFindByDefInternal(def, mem, false)) < 0)
+        ret = virDomainMemoryFindByDefInternal(def, mem, true);
+
+    return ret;
+}
+
+
+int
+virDomainMemoryInsert(virDomainDefPtr def,
+                      virDomainMemoryDefPtr mem)
+{
+    int id = def->nmems;
+
+    if (mem->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE &&
+        virDomainDefHasDeviceAddress(def, &mem->info)) {
+        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                       _("Domain already contains a device with the same "
+                         "address"));
+        return -1;
+    }
+
+    if (VIR_APPEND_ELEMENT(def->mems, def->nmems, mem) < 0)
+        return -1;
+
+    return id;
+}
+
+
+virDomainMemoryDefPtr
+virDomainMemoryRemove(virDomainDefPtr def,
+                      int idx)
+{
+    virDomainMemoryDefPtr ret = def->mems[idx];
+    VIR_DELETE_ELEMENT(def->mems, idx, def->nmems);
+    return ret;
+}
+
+
 char *
 virDomainDefGetDefaultEmulator(virDomainDefPtr def,
                                virCapsPtr caps)

src/conf/domain_conf.h

@@ -2859,6 +2859,16 @@ virDomainChrDefGetSecurityLabelDef(virDomainChrDefPtr def, const char *model);
 typedef const char* (*virEventActionToStringFunc)(int type);
 typedef int (*virEventActionFromStringFunc)(const char *type);
 
+int virDomainMemoryInsert(virDomainDefPtr def, virDomainMemoryDefPtr mem)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
+virDomainMemoryDefPtr virDomainMemoryRemove(virDomainDefPtr def, int idx)
+    ATTRIBUTE_NONNULL(1);
+int virDomainMemoryFindByDef(virDomainDefPtr def, virDomainMemoryDefPtr mem)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
+int virDomainMemoryFindInactiveByDef(virDomainDefPtr def,
+                                     virDomainMemoryDefPtr mem)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
+
 VIR_ENUM_DECL(virDomainTaint)
 VIR_ENUM_DECL(virDomainVirt)
 VIR_ENUM_DECL(virDomainBoot)

src/libvirt_private.syms

@@ -335,6 +335,10 @@ virDomainLockFailureTypeToString;
 virDomainMemballoonModelTypeFromString;
 virDomainMemballoonModelTypeToString;
 virDomainMemoryDefFree;
+virDomainMemoryFindByDef;
+virDomainMemoryFindInactiveByDef;
+virDomainMemoryInsert;
+virDomainMemoryRemove;
 virDomainNetAppendIpAddress;
 virDomainNetDefFormat;
 virDomainNetDefFree;

src/qemu/qemu_driver.c

@@ -7999,7 +7999,10 @@ qemuDomainAttachDeviceConfig(virQEMUCapsPtr qemuCaps,
         break;
 
     case VIR_DOMAIN_DEVICE_MEMORY:
-        /* TODO: implement later */
+        if (virDomainMemoryInsert(vmdef, dev->data.memory) < 0)
+            return -1;
+        dev->data.memory = NULL;
+        break;
 
     case VIR_DOMAIN_DEVICE_INPUT:
     case VIR_DOMAIN_DEVICE_SOUND:
@@ -8127,7 +8130,15 @@ qemuDomainDetachDeviceConfig(virDomainDefPtr vmdef,
         break;
 
     case VIR_DOMAIN_DEVICE_MEMORY:
-        /* TODO: implement later */
+        if ((idx = virDomainMemoryFindInactiveByDef(vmdef,
+                                                    dev->data.memory)) < 0) {
+            virReportError(VIR_ERR_OPERATION_FAILED, "%s",
+                           _("matching memory device was not found"));
+            return -1;
+        }
+
+        virDomainMemoryDefFree(virDomainMemoryRemove(vmdef, idx));
+        break;
 
     case VIR_DOMAIN_DEVICE_INPUT:
     case VIR_DOMAIN_DEVICE_SOUND: