Public API for post-copy migration bandwidth

This patch adds a new VIR_MIGRATE_PARAM_BANDWIDTH_POSTCOPY typed
parameter for virDomainMigrate3 and virDomainMigrateToURI3 for setting
maximum post-copy migration bandwidth.

In case the initial VIR_MIGRATE_PARAM_BANDWIDTH_POSTCOPY value turns out
to be suboptimal a new VIR_DOMAIN_MIGRATE_MAX_SPEED_POSTCOPY flag for
virDomainMigrateSetMaxSpeed and virDomainMigrateGetMaxSpeed may be used
to set/get the maximum post-copy migration bandwidth while migration is
already running.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

include/libvirt/libvirt-domain.h

@@ -903,6 +903,15 @@ typedef enum {
  */
 # define VIR_MIGRATE_PARAM_BANDWIDTH         "bandwidth"
 
+/**
+ * VIR_MIGRATE_PARAM_BANDWIDTH_POSTCOPY:
+ *
+ * virDomainMigrate* params field: the maximum bandwidth (in MiB/s) that will
+ * be used for post-copy phase of a migration as VIR_TYPED_PARAM_ULLONG. If set
+ * to 0 or omitted, post-copy migration speed will not be limited.
+ */
+# define VIR_MIGRATE_PARAM_BANDWIDTH_POSTCOPY "bandwidth.postcopy"
+
 /**
  * VIR_MIGRATE_PARAM_GRAPHICS_URI:
  *
@@ -1062,6 +1071,12 @@ int virDomainMigrateSetCompressionCache(virDomainPtr domain,
                                         unsigned long long cacheSize,
                                         unsigned int flags);
 
+/* Domain migration speed flags. */
+typedef enum {
+    /* Set or get maximum speed of post-copy migration. */
+    VIR_DOMAIN_MIGRATE_MAX_SPEED_POSTCOPY = (1 << 0),
+} virDomainMigrateMaxSpeedFlags;
+
 int virDomainMigrateSetMaxSpeed(virDomainPtr domain,
                                 unsigned long bandwidth,
                                 unsigned int flags);

src/libvirt-domain.c

@@ -9036,11 +9036,13 @@ virDomainMigrateSetCompressionCache(virDomainPtr domain,
  * virDomainMigrateSetMaxSpeed:
  * @domain: a domain object
  * @bandwidth: migration bandwidth limit in MiB/s
- * @flags: extra flags; not used yet, so callers should always pass 0
+ * @flags: bitwise-OR of virDomainMigrateMaxSpeedFlags
  *
  * The maximum bandwidth (in MiB/s) that will be used to do migration
  * can be specified with the bandwidth parameter. Not all hypervisors
- * will support a bandwidth cap
+ * will support a bandwidth cap. When VIR_DOMAIN_MIGRATE_MAX_SPEED_POSTCOPY
+ * is set in @flags, this API sets the maximum bandwidth for the post-copy
+ * phase of the migration.
  *
  * Returns 0 in case of success, -1 otherwise.
  */
@@ -9077,10 +9079,13 @@ virDomainMigrateSetMaxSpeed(virDomainPtr domain,
  * virDomainMigrateGetMaxSpeed:
  * @domain: a domain object
  * @bandwidth: return value of current migration bandwidth limit in MiB/s
- * @flags: extra flags; not used yet, so callers should always pass 0
+ * @flags: bitwise-OR of virDomainMigrateMaxSpeedFlags
  *
  * Get the current maximum bandwidth (in MiB/s) that will be used if the
  * domain is migrated.  Not all hypervisors will support a bandwidth limit.
+ * When VIR_DOMAIN_MIGRATE_MAX_SPEED_POSTCOPY is set in @flags, this API
+ * gets the current maximum bandwidth for the post-copy phase of the
+ * migration.
  *
  * Returns 0 in case of success, -1 otherwise.
  */