xl/libxtl: Remove glitch in xl migrate log output

* Provide a new XTL_STDIOSTREAM_HIDE_PROGRESS flag in the stdio logger
* Provide a way to adjust the flags after logger setup
* Use these to disable progress output from the migration receiver, as
  the sender is also sending progress information.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

tools/libxc/xentoollog.h

@@ -51,8 +51,9 @@ struct xentoollog_logger {
 
 /*---------- facilities for consuming log messages ----------*/
 
-#define XTL_STDIOSTREAM_SHOW_PID  01u
-#define XTL_STDIOSTREAM_SHOW_DATE 02u
+#define XTL_STDIOSTREAM_SHOW_PID      01u
+#define XTL_STDIOSTREAM_SHOW_DATE     02u
+#define XTL_STDIOSTREAM_HIDE_PROGRESS 04u
 
 typedef struct xentoollog_logger_stdiostream  xentoollog_logger_stdiostream;
 
@@ -61,6 +62,12 @@ xentoollog_logger_stdiostream *xtl_createlogger_stdiostream
     /* may return 0 if malloc fails, in which case error was logged */
     /* destroy on this logger does not close the file */
 
+void xtl_stdiostream_set_minlevel(xentoollog_logger_stdiostream*,
+                                  xentoollog_level min_level);
+void xtl_stdiostream_adjust_flags(xentoollog_logger_stdiostream*,
+                                  unsigned set_flags, unsigned clear_flags);
+  /* if set_flags and clear_flags overlap, set_flags takes precedence */
+
 void xtl_logger_destroy(struct xentoollog_logger *logger /* 0 is ok */);
 
 

tools/libxc/xtl_logger_stdio.c

@@ -75,6 +75,9 @@ static void stdiostream_progress(struct xentoollog_logger *logger_in,
     int newpel, extra_erase;
     xentoollog_level this_level;
 
+    if (!(lg->flags & XTL_STDIOSTREAM_HIDE_PROGRESS))
+        return;
+
     if (percent < lg->progress_last_percent) {
         this_level = XTL_PROGRESS;
     } else if (percent == lg->progress_last_percent) {
@@ -108,6 +111,18 @@ static void stdiostream_destroy(struct xentoollog_logger *logger_in) {
     free(lg);
 }
 
+void xtl_stdiostream_set_minlevel(xentoollog_logger_stdiostream *lg,
+                                  xentoollog_level min_level) {
+    lg->min_level = min_level;
+}
+
+void xtl_stdiostream_adjust_flags(xentoollog_logger_stdiostream *lg,
+                                  unsigned set_flags, unsigned clear_flags) {
+    unsigned new_flags = (lg->flags & ~clear_flags) | set_flags;
+    if (new_flags & XTL_STDIOSTREAM_HIDE_PROGRESS)
+        progress_erase(lg);
+    lg->flags = new_flags;
+}
 
 xentoollog_logger_stdiostream *xtl_createlogger_stdiostream
         (FILE *f, xentoollog_level min_level, unsigned flags) {

tools/libxl/xl_cmdimpl.c

@@ -1923,6 +1923,8 @@ static void migrate_domain(char *domain_spec, const char *rune,
     save_domain_core_writeconfig(send_fd, "migration stream",
                                  config_data, config_len);
 
+    xtl_stdiostream_adjust_flags(logger, XTL_STDIOSTREAM_HIDE_PROGRESS, 0);
+
     memset(&suspinfo, 0, sizeof(suspinfo));
     suspinfo.flags |= XL_SUSPEND_LIVE;
     rc = libxl_domain_suspend(&ctx, &suspinfo, domid, send_fd);
@@ -1932,13 +1934,17 @@ static void migrate_domain(char *domain_spec, const char *rune,
         goto failed_resume;
     }
 
-    fprintf(stderr, "migration sender: Transfer complete.\n");
+    //fprintf(stderr, "migration sender: Transfer complete.\n");
+    // Should only be printed when debugging as it's a bit messy with
+    // progress indication.
 
     rc = migrate_read_fixedmessage(recv_fd, migrate_receiver_ready,
                                    sizeof(migrate_receiver_ready),
                                    "ready message", rune);
     if (rc) goto failed_resume;
 
+    xtl_stdiostream_adjust_flags(logger, 0, XTL_STDIOSTREAM_HIDE_PROGRESS);
+
     /* right, at this point we are about give the destination
      * permission to rename and resume, so we must first rename the
      * domain away ourselves */