qemu: capabilities: Lock out incremental backup capability without blockdev

Blockdev is required to do incremental backups properly. Add a helper
function for locking out capabilities and export it to allow re-doing
the processing if a different code path modifies capabilities.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index b93fd8310f8381f523af6a6b70859923f44f1d77..edb128c8811e6054c833007d50f9ec5b24e50302 100644 (file)
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -4577,6 +4577,21 @@ virQEMUCapsInitQMPVersionCaps(virQEMUCapsPtr qemuCaps)
 }
 
 
+/**
+ * virQEMUCapsInitProcessCapsInterlock:
+ * @qemuCaps: QEMU capabilities
+ *
+ * A capability which requires a different capability being present in order
+ * for libvirt to be able to drive it properly should be processed here.
+ */
+void
+virQEMUCapsInitProcessCapsInterlock(virQEMUCapsPtr qemuCaps)
+{
+    if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_BLOCKDEV))
+        virQEMUCapsClear(qemuCaps, QEMU_CAPS_INCREMENTAL_BACKUP);
+}
+
+
 /**
  * virQEMUCapsInitProcessCaps:
  * @qemuCaps: QEMU capabilities
@@ -4627,6 +4642,8 @@ virQEMUCapsInitProcessCaps(virQEMUCapsPtr qemuCaps)
         virQEMUCapsGet(qemuCaps, QEMU_CAPS_SCSI_DISK_DEVICE_ID) &&
         virQEMUCapsGet(qemuCaps, QEMU_CAPS_SAVEVM_MONITOR_NODES))
         virQEMUCapsSet(qemuCaps, QEMU_CAPS_BLOCKDEV);
+
+    virQEMUCapsInitProcessCapsInterlock(qemuCaps);
 }
 
 

diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 3fd8bebe7927c41015e1ce983ec39cbeac7623f7..4d7d836e8c32f082181616413be274f895ddb96e 100644 (file)
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -555,6 +555,8 @@ void virQEMUCapsClear(virQEMUCapsPtr qemuCaps,
 bool virQEMUCapsGet(virQEMUCapsPtr qemuCaps,
                     virQEMUCapsFlags flag);
 
+void virQEMUCapsInitProcessCapsInterlock(virQEMUCapsPtr qemuCaps);
+
 bool virQEMUCapsHasPCIMultiBus(virQEMUCapsPtr qemuCaps,
                                const virDomainDef *def);