[libvirt] [PATCH 24/25] qemu: command: Add infrastructure for object specified disk sources

[Peter Krempa]

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 |  1 +
 src/qemu/qemu_command.c  | 83 ++++++++++++++++++++++++++++++++++++------------
 src/util/virqemu.c       | 21 ++++++++++++
 src/util/virqemu.h       |  2 ++
 4 files changed, 86 insertions(+), 21 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 296b036..4614a7b 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2209,6 +2209,7 @@ virQEMUBuildBufferEscapeComma;
 virQEMUBuildCommandLineJSON;
 virQEMUBuildCommandLineJSONArrayBitmap;
 virQEMUBuildCommandLineJSONArrayNumbered;
+virQEMUBuildDriveCommandlineFromJSON;
 virQEMUBuildLuksOpts;
 virQEMUBuildObjectCommandlineFromJSON;

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 3b42b73..5a5df7d 100644
--- a/src/qemu/qemu_command.c
+++ b/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))
@@ -1123,31 +1156,38 @@ 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;
+            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:");
         }

-        virBufferAddLit(buf, "fat:");
+        virQEMUBuildBufferEscapeComma(buf, source);
+    } else {
+        if (!(source = virQEMUBuildDriveCommandlineFromJSON(srcprops)))
+            goto cleanup;

-        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) {
@@ -1168,6 +1208,7 @@ qemuBuildDriveSourceStr(virDomainDiskDefPtr disk,

  cleanup:
     VIR_FREE(source);
+    virJSONValueFree(srcprops);
     return ret;
 }

diff --git a/src/util/virqemu.c b/src/util/virqemu.c
index 20410f7..a1ba562 100644
--- a/src/util/virqemu.c
+++ b/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
diff --git a/src/util/virqemu.h b/src/util/virqemu.h
index 40cd9b8..f3c2b69 100644
--- a/src/util/virqemu.h
+++ b/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,
-- 
2.9.0