libxl: support serial list

Add support for multi serial devices, after this patch virsh can be used to
connect different serial devices of running domains. E.g.
vish # console <xxx> --devname serial<xxx>

Note:
This depends on a xen/libxl bug fix to have libxl_console_get_tty(...) correctly
returning the tty path (as opposed to always returning the first one).
[0] https://lists.xen.org/archives/html/xen-devel/2016-08/msg00438.htmlSigned-off-by: NBob Liu <bob.liu@oracle.com>

src/libxl/libxl_conf.c

@@ -431,14 +431,31 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
         }
 
         if (def->nserials) {
-            if (def->nserials > 1) {
+            if (def->nserials == 1) {
+                if (libxlMakeChrdevStr(def->serials[0], &b_info->u.hvm.serial) <
+                    0)
+                    return -1;
+            } else {
+#ifdef LIBXL_HAVE_BUILDINFO_SERIAL_LIST
+                if (VIR_ALLOC_N(b_info->u.hvm.serial_list, def->nserials + 1) <
+                    0)
+                    return -1;
+                for (i = 0; i < def->nserials; i++) {
+                    if (libxlMakeChrdevStr(def->serials[i],
+                                           &b_info->u.hvm.serial_list[i]) < 0)
+                    {
+                        libxl_string_list_dispose(&b_info->u.hvm.serial_list);
+                        return -1;
+                    }
+                }
+                b_info->u.hvm.serial_list[i] = NULL;
+#else
                 virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                                "%s",
                                _("Only one serial device is supported by libxl"));
                 return -1;
+#endif
             }
-            if (libxlMakeChrdevStr(def->serials[0], &b_info->u.hvm.serial) < 0)
-                return -1;
         }
 
         if (def->nparallels) {

src/libxl/libxl_domain.c

@@ -983,18 +983,20 @@ libxlConsoleCallback(libxl_ctx *ctx, libxl_event *ev, void *for_callback)
 {
     virDomainObjPtr vm = for_callback;
     size_t i;
+    virDomainChrDefPtr chr;
+    char *console = NULL;
+    int ret;
 
     virObjectLock(vm);
     for (i = 0; i < vm->def->nconsoles; i++) {
-        virDomainChrDefPtr chr = vm->def->consoles[i];
+        chr = vm->def->consoles[i];
+
         if (i == 0 &&
             chr->targetType == VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL)
             chr = vm->def->serials[0];
 
         if (chr->source.type == VIR_DOMAIN_CHR_TYPE_PTY) {
             libxl_console_type console_type;
-            char *console = NULL;
-            int ret;
 
             console_type =
                 (chr->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_SERIAL ?
@@ -1012,6 +1014,27 @@ libxlConsoleCallback(libxl_ctx *ctx, libxl_event *ev, void *for_callback)
             VIR_FREE(console);
         }
     }
+    for (i = 0; i < vm->def->nserials; i++) {
+        chr = vm->def->serials[i];
+
+        ignore_value(virAsprintf(&chr->info.alias, "serial%zd", i));
+        if (chr->source.type == VIR_DOMAIN_CHR_TYPE_PTY) {
+            if (chr->source.data.file.path)
+                continue;
+            ret = libxl_console_get_tty(ctx, ev->domid,
+                                        chr->target.port,
+                                        LIBXL_CONSOLE_TYPE_SERIAL,
+                                        &console);
+            if (!ret) {
+                VIR_FREE(chr->source.data.file.path);
+                if (console && console[0] != '\0') {
+                    ignore_value(VIR_STRDUP(chr->source.data.file.path,
+                                            console));
+                }
+            }
+            VIR_FREE(console);
+        }
+    }
     virObjectUnlock(vm);
     libxl_event_free(ctx, ev);
 }

src/libxl/libxl_driver.c

@@ -4679,13 +4679,6 @@ libxlDomainOpenConsole(virDomainPtr dom,
 
     virCheckFlags(VIR_DOMAIN_CONSOLE_FORCE, -1);
 
-    if (dev_name) {
-        /* XXX support device aliases in future */
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("Named device aliases are not supported"));
-        goto cleanup;
-    }
-
     if (!(vm = libxlDomObjFromDomain(dom)))
         goto cleanup;
 
@@ -4701,8 +4694,16 @@ libxlDomainOpenConsole(virDomainPtr dom,
     }
 
     priv = vm->privateData;
+    if (dev_name) {
+        size_t i;
 
-    if (vm->def->nconsoles) {
+        for (i = 0; !chr && i < vm->def->nserials; i++) {
+            if (STREQ(dev_name, vm->def->serials[i]->info.alias)) {
+                chr = vm->def->serials[i];
+                break;
+            }
+        }
+    } else if (vm->def->nconsoles) {
         chr = vm->def->consoles[0];
         if (chr->targetType == VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL)
             chr = vm->def->serials[0];