qemu: block: enable the snapshot image deletion feature

With all plumbing in place, we can now enable the new functionality.
Signed-off-by: NPavel Mores <pmores@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>

src/qemu/qemu_driver.c

@@ -18544,10 +18544,10 @@ qemuDomainBlockCommit(virDomainPtr dom,
     bool persistjob = false;
     bool blockdev = false;
 
-    /* XXX Add support for COMMIT_DELETE */
     virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW |
                   VIR_DOMAIN_BLOCK_COMMIT_ACTIVE |
                   VIR_DOMAIN_BLOCK_COMMIT_RELATIVE |
+                  VIR_DOMAIN_BLOCK_COMMIT_DELETE |
                   VIR_DOMAIN_BLOCK_COMMIT_BANDWIDTH_BYTES, -1);
 
     if (!(vm = qemuDomainObjFromDomain(dom)))
@@ -18568,6 +18568,12 @@ qemuDomainBlockCommit(virDomainPtr dom,
 
     blockdev = virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV);
 
+    if (!blockdev && (flags & VIR_DOMAIN_BLOCK_COMMIT_DELETE)) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("deleting committed images is not supported by this VM"));
+        goto endjob;
+    }
+
     /* Convert bandwidth MiB to bytes, if necessary */
     if (!(flags & VIR_DOMAIN_BLOCK_COMMIT_BANDWIDTH_BYTES)) {
         if (speed > LLONG_MAX >> 20) {
@@ -18686,7 +18692,8 @@ qemuDomainBlockCommit(virDomainPtr dom,
         goto endjob;
 
     if (!(job = qemuBlockJobDiskNewCommit(vm, disk, top_parent, topSource,
-                                          baseSource, false)))
+                                          baseSource,
+                                          flags & VIR_DOMAIN_BLOCK_COMMIT_DELETE)))
         goto endjob;
 
     disk->mirrorState = VIR_DOMAIN_DISK_MIRROR_STATE_NONE;