virsh: migrate: Add support for VIR_MIGRATE_PARAM_MIGRATE_DISKS_TARGET_ZERO

Add '--migrate-disks-target-zero' to pass the list of pre-zeroed disk
images.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

docs/manpages/virsh.rst

@@ -3722,6 +3722,7 @@ migrate
       [--timeout seconds [--timeout-suspend | --timeout-postcopy]]
       [--xml file]
       [--migrate-disks disk-list] [--migrate-disks-detect-zeroes disk-list]
+      [--migrate-disks-target-zero disk-list]
       [--disks-port port]
       [--compressed] [--comp-methods method-list]
       [--comp-mt-level] [--comp-mt-threads] [--comp-mt-dthreads]
@@ -3760,6 +3761,9 @@ disk target names enables zeroed block detection for the listed migrated disks.
 These blocks are not transferred or allocated (requires that 'discard' option
 on given disk is set to 'unmap') on destination, effectively sparsifying the
 disk at the cost of CPU overhead.
+The *--migrate-disks-target-zero* option which takes a comma separated list of
+disk target names specifies disk images where the target was zeroed out prior
+to the migration and thus hypervisor will not attempt to zero them.
 With *--copy-storage-synchronous-writes* flag used the disk data migration will
 synchronously handle guest disk writes to both the original source and the
 destination to ensure that the disk migration converges at the price of possibly

tools/virsh-domain.c

@@ -11218,6 +11218,11 @@ static const vshCmdOptDef opts_migrate[] = {
      .completer = virshDomainMigrateDisksCompleter,
      .help = N_("comma separated list of disks to be migrated with zero detection enabled")
     },
+    {.name = "migrate-disks-target-zero",
+     .type = VSH_OT_STRING,
+     .completer = virshDomainMigrateDisksCompleter,
+     .help = N_("comma separated list of disks to be migrated with assumption that target image is zeroed")
+    },
     {.name = "disks-port",
      .type = VSH_OT_INT,
      .unwanted_positional = true,
@@ -11461,6 +11466,27 @@ doMigrate(void *opaque)
         }
     }
 
+    if (vshCommandOptString(ctl, cmd, "migrate-disks-target-zero", &opt) < 0)
+        goto out;
+    if (opt) {
+        g_autofree char **val = NULL;
+
+        if (!(flags & (VIR_MIGRATE_NON_SHARED_DISK | VIR_MIGRATE_NON_SHARED_INC))) {
+            vshError(ctl, "%s", _("'--migrate-disks-target-zero' requires one of '--copy-storage-all', '--copy-storage-inc'"));
+            goto out;
+        }
+
+        val = g_strsplit(opt, ",", 0);
+
+        if (virTypedParamsAddStringList(&params,
+                                        &nparams,
+                                        &maxparams,
+                                        VIR_MIGRATE_PARAM_MIGRATE_DISKS_TARGET_ZERO,
+                                        (const char **)val) < 0) {
+            goto save_error;
+        }
+    }
+
     if (vshCommandOptString(ctl, cmd, "comp-methods", &opt) < 0)
         goto out;
     if (opt) {