qemu: command: Add infrastructure for object specified disk sources

To allow richer definitions of disk sources add infrastructure that will
allow to register functionst generating a JSON object based definition.

This infrastructure will then convert the definition to the proper
command line syntax and use it in cases where it's necessary. This will
allow to keep legacy definitions for back-compat when possible and use
the new definitions for the configurations requiring them.

src/libvirt_private.syms

@@ -2207,6 +2207,7 @@ virQEMUBuildBufferEscapeComma;
 virQEMUBuildCommandLineJSON;
 virQEMUBuildCommandLineJSONArrayBitmap;
 virQEMUBuildCommandLineJSONArrayNumbered;
+virQEMUBuildDriveCommandlineFromJSON;
 virQEMUBuildLuksOpts;
 virQEMUBuildObjectCommandlineFromJSON;
 

src/qemu/qemu_command.c

@@ -916,6 +916,34 @@ qemuBuildNetworkDriveStr(virStorageSourcePtr src,
 }
 
 
+static int
+qemuGetDriveSourceProps(virStorageSourcePtr src,
+                        virJSONValuePtr *props)
+{
+    int actualType = virStorageSourceGetActualType(src);
+    virJSONValuePtr fileprops = NULL;
+
+    *props = NULL;
+
+    switch ((virStorageType) actualType) {
+    case VIR_STORAGE_TYPE_BLOCK:
+    case VIR_STORAGE_TYPE_FILE:
+    case VIR_STORAGE_TYPE_DIR:
+    case VIR_STORAGE_TYPE_VOLUME:
+    case VIR_STORAGE_TYPE_NONE:
+    case VIR_STORAGE_TYPE_LAST:
+    case VIR_STORAGE_TYPE_NETWORK:
+        break;
+    }
+
+    if (fileprops &&
+        virJSONValueObjectCreate(props, "a:file", fileprops, NULL) < 0)
+        return -1;
+
+    return 0;
+}
+
+
 int
 qemuGetDriveSourceString(virStorageSourcePtr src,
                          qemuDomainSecretInfoPtr secinfo,
@@ -1101,14 +1129,19 @@ qemuBuildDriveSourceStr(virDomainDiskDefPtr disk,
     qemuDomainDiskPrivatePtr diskPriv = QEMU_DOMAIN_DISK_PRIVATE(disk);
     qemuDomainSecretInfoPtr secinfo = diskPriv->secinfo;
     qemuDomainSecretInfoPtr encinfo = diskPriv->encinfo;
+    virJSONValuePtr srcprops = NULL;
     char *source = NULL;
     int ret = -1;
 
-    if (qemuGetDriveSourceString(disk->src, secinfo, &source) < 0)
+    if (qemuGetDriveSourceProps(disk->src, &srcprops) < 0)
+        goto cleanup;
+
+    if (!srcprops &&
+        qemuGetDriveSourceString(disk->src, secinfo, &source) < 0)
         goto cleanup;
 
     /* nothing to format if the drive is empty */
-    if (!source ||
+    if (!(source || srcprops) ||
         ((disk->device == VIR_DOMAIN_DISK_DEVICE_FLOPPY ||
           disk->device == VIR_DOMAIN_DISK_DEVICE_CDROM) &&
          disk->tray_status == VIR_DOMAIN_DISK_TRAY_OPEN)) {
@@ -1125,31 +1158,38 @@ qemuBuildDriveSourceStr(virDomainDiskDefPtr disk,
         goto cleanup;
     }
 
-    virBufferAddLit(buf, "file=");
+    if (source) {
+        virBufferAddLit(buf, "file=");
 
-    /* for now the DIR based storage is handled by the magic FAT format */
-    if (actualType == VIR_STORAGE_TYPE_DIR) {
-        if (disk->src->format > 0 &&
-            disk->src->format != VIR_STORAGE_FILE_FAT) {
-            virReportError(VIR_ERR_INTERNAL_ERROR,
-                           _("unsupported disk driver type for '%s'"),
-                           virStorageFileFormatTypeToString(disk->src->format));
-            goto cleanup;
+        /* for now the DIR based storage is handled by the magic FAT format */
+        if (actualType == VIR_STORAGE_TYPE_DIR) {
+            if (disk->src->format > 0 &&
+                disk->src->format != VIR_STORAGE_FILE_FAT) {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               _("unsupported disk driver type for '%s'"),
+                               virStorageFileFormatTypeToString(disk->src->format));
+                goto cleanup;
+            }
+
+            if (!disk->src->readonly) {
+                virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                               _("cannot create virtual FAT disks in read-write mode"));
+                goto cleanup;
+            }
+
+            virBufferAddLit(buf, "fat:");
+
+            if (disk->device == VIR_DOMAIN_DISK_DEVICE_FLOPPY)
+                virBufferAddLit(buf, "floppy:");
         }
 
-        if (!disk->src->readonly) {
-            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                           _("cannot create virtual FAT disks in read-write mode"));
+        virQEMUBuildBufferEscapeComma(buf, source);
+    } else {
+        if (!(source = virQEMUBuildDriveCommandlineFromJSON(srcprops)))
             goto cleanup;
-        }
 
-        virBufferAddLit(buf, "fat:");
-
-        if (disk->device == VIR_DOMAIN_DISK_DEVICE_FLOPPY)
-            virBufferAddLit(buf, "floppy:");
+        virBufferAdd(buf, source, -1);
     }
-
-    virQEMUBuildBufferEscapeComma(buf, source);
     virBufferAddLit(buf, ",");
 
     if (secinfo && secinfo->type == VIR_DOMAIN_SECRET_INFO_TYPE_AES) {
@@ -1170,6 +1210,7 @@ qemuBuildDriveSourceStr(virDomainDiskDefPtr disk,
 
  cleanup:
     VIR_FREE(source);
+    virJSONValueFree(srcprops);
     return ret;
 }
 

src/util/virqemu.c

@@ -264,6 +264,27 @@ virQEMUBuildObjectCommandlineFromJSON(const char *type,
 }
 
 
+char *
+virQEMUBuildDriveCommandlineFromJSON(const virJSONValue *srcdef)
+{
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+    char *ret = NULL;
+
+    if (virQEMUBuildCommandLineJSON(srcdef, &buf,
+                                    virQEMUBuildCommandLineJSONArrayNumbered) < 0)
+        goto cleanup;
+
+    if (virBufferCheckError(&buf) < 0)
+        goto cleanup;
+
+    ret = virBufferContentAndReset(&buf);
+
+ cleanup:
+    virBufferFreeAndReset(&buf);
+    return ret;
+}
+
+
 /**
  * virQEMUBuildBufferEscapeComma:
  * @buf: buffer to append the escaped string

src/util/virqemu.h

@@ -47,6 +47,8 @@ char *virQEMUBuildObjectCommandlineFromJSON(const char *type,
                                             const char *alias,
                                             virJSONValuePtr props);
 
+char *virQEMUBuildDriveCommandlineFromJSON(const virJSONValue *src);
+
 void virQEMUBuildBufferEscapeComma(virBufferPtr buf, const char *str);
 void virQEMUBuildLuksOpts(virBufferPtr buf,
                           virStorageEncryptionInfoDefPtr enc,