libvirt/qemu - support persistent attach/detach disks

Support changes of disks by MODIFY_CONFIG for qemu.

This patch includes patches for qemu's disk to support
virDomainAt(De)tachDeviceFlags with VIR_DOMAIN_DEVICE_MODIFY_CONFIG.

Other devices can be added incrementally.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

* /src/conf/domain_conf.c
(virDomainDiskIndexByName): returns array index of disk in vmdef.
(virDomainDiskRemoveByName): removes a disk which has the name in vmdef.
* src/qemu/qemu_driver.c
(qemuDomainAttachDeviceConfig): add support for Disks.
(qemuDomainDetachDeviceConfig): add support for Disks.

src/conf/domain_conf.c

@@ -5007,6 +5007,19 @@ virVirtualPortProfileFormat(virBufferPtr buf,
     virBufferVSprintf(buf, "%s</virtualport>\n", indent);
 }
 
+int virDomainDiskIndexByName(virDomainDefPtr def, const char *name)
+{
+    virDomainDiskDefPtr vdisk;
+    int i;
+
+    for (i = 0; i < def->ndisks; i++) {
+        vdisk = def->disks[i];
+        if (STREQ(vdisk->dst, name))
+            return i;
+    }
+    return -1;
+}
+
 int virDomainDiskInsert(virDomainDefPtr def,
                         virDomainDiskDefPtr disk)
 {
@@ -5078,6 +5091,15 @@ void virDomainDiskRemove(virDomainDefPtr def, size_t i)
     }
 }
 
+int virDomainDiskRemoveByName(virDomainDefPtr def, const char *name)
+{
+    int i = virDomainDiskIndexByName(def, name);
+    if (i < 0)
+        return -1;
+    virDomainDiskRemove(def, i);
+    return 0;
+}
+
 
 int virDomainControllerInsert(virDomainDefPtr def,
                               virDomainControllerDefPtr controller)

src/conf/domain_conf.h

@@ -1329,6 +1329,7 @@ int virDomainVcpupinAdd(virDomainDefPtr def,
                         int maplen,
                         int vcpu);
 
+int virDomainDiskIndexByName(virDomainDefPtr def, const char *name);
 int virDomainDiskInsert(virDomainDefPtr def,
                         virDomainDiskDefPtr disk);
 void virDomainDiskInsertPreAlloced(virDomainDefPtr def,
@@ -1336,6 +1337,7 @@ void virDomainDiskInsertPreAlloced(virDomainDefPtr def,
 int virDomainDiskDefAssignAddress(virCapsPtr caps, virDomainDiskDefPtr def);
 
 void virDomainDiskRemove(virDomainDefPtr def, size_t i);
+int virDomainDiskRemoveByName(virDomainDefPtr def, const char *name);
 
 int virDomainControllerInsert(virDomainDefPtr def,
                               virDomainControllerDefPtr controller);

src/libvirt_private.syms

@@ -246,11 +246,13 @@ virDomainDiskDefFree;
 virDomainDiskDeviceTypeToString;
 virDomainDiskErrorPolicyTypeFromString;
 virDomainDiskErrorPolicyTypeToString;
+virDomainDiskIndexByName;
 virDomainDiskInsert;
 virDomainDiskInsertPreAlloced;
 virDomainDiskIoTypeFromString;
 virDomainDiskIoTypeToString;
 virDomainDiskRemove;
+virDomainDiskRemoveByName;
 virDomainDiskTypeFromString;
 virDomainDiskTypeToString;
 virDomainFSDefFree;

src/qemu/qemu_driver.c

@@ -4077,10 +4077,32 @@ qemuDomainUpdateDeviceLive(virDomainObjPtr vm,
 }
 
 static int
-qemuDomainAttachDeviceConfig(virDomainDefPtr vmdef ATTRIBUTE_UNUSED,
+qemuDomainAttachDeviceConfig(virDomainDefPtr vmdef,
                              virDomainDeviceDefPtr dev)
 {
+    virDomainDiskDefPtr disk;
+
     switch (dev->type) {
+    case VIR_DOMAIN_DEVICE_DISK:
+        disk = dev->data.disk;
+        if (virDomainDiskIndexByName(vmdef, disk->dst) >= 0) {
+            qemuReportError(VIR_ERR_INVALID_ARG,
+                            _("target %s already exists."), disk->dst);
+            return -1;
+        }
+        if (virDomainDiskInsert(vmdef, disk)) {
+            virReportOOMError();
+            return -1;
+        }
+        /* vmdef has the pointer. Generic codes for vmdef will do all jobs */
+        dev->data.disk = NULL;
+        if (disk->bus != VIR_DOMAIN_DISK_BUS_VIRTIO)
+            if (virDomainDefAddImplicitControllers(vmdef) < 0)
+                return -1;
+        if (qemuDomainAssignPCIAddresses(vmdef) < 0)
+            return -1;
+        break;
+
     default:
          qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                          _("persistent attach of device is not supported"));
@@ -4091,10 +4113,20 @@ qemuDomainAttachDeviceConfig(virDomainDefPtr vmdef ATTRIBUTE_UNUSED,
 
 
 static int
-qemuDomainDetachDeviceConfig(virDomainDefPtr vmdef ATTRIBUTE_UNUSED,
+qemuDomainDetachDeviceConfig(virDomainDefPtr vmdef,
                              virDomainDeviceDefPtr dev)
 {
+    virDomainDiskDefPtr disk;
+
     switch (dev->type) {
+    case VIR_DOMAIN_DEVICE_DISK:
+        disk = dev->data.disk;
+        if (virDomainDiskRemoveByName(vmdef, disk->dst)) {
+            qemuReportError(VIR_ERR_INVALID_ARG,
+                            _("no target device %s"), disk->dst);
+            return -1;
+        }
+        break;
     default:
         qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                         _("persistent detach of device is not supported"));