libxl: Add API to retrieve domain console tty

This api retrieve domain console from xenstore. With this new api, it is easy
to implement "virsh console" command in libvirt libxl driver.

Signed-off-by: Bamvor Jian Zhang <bjzhang@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- use NOGC instead of 0 to allow improvements to this infrastructure
         in the future ]
Committed-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 1f7ccc4aea66bf313d6ccc88e1d0bf399df600d2..c5c634378d9f2004aa36359526b3228164a85629 100644 (file)
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -1217,7 +1217,8 @@ out:
     return rc;
 }
 
-int libxl_console_exec(libxl_ctx *ctx, uint32_t domid, int cons_num, libxl_console_type type)
+int libxl_console_exec(libxl_ctx *ctx, uint32_t domid, int cons_num,
+                       libxl_console_type type)
 {
     GC_INIT(ctx);
     char *p = libxl__sprintf(gc, "%s/xenconsole", libxl__private_bindir_path());
@@ -1243,34 +1244,116 @@ out:
     return ERROR_FAIL;
 }
 
-int libxl_primary_console_exec(libxl_ctx *ctx, uint32_t domid_vm)
+int libxl_console_get_tty(libxl_ctx *ctx, uint32_t domid, int cons_num,
+                          libxl_console_type type, char **path)
+{
+    GC_INIT(ctx);
+    char *dom_path;
+    char *tty_path;
+    char *tty;
+    int rc;
+
+    dom_path = libxl__xs_get_dompath(gc, domid);
+    if (!dom_path) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    switch (type) {
+    case LIBXL_CONSOLE_TYPE_SERIAL:
+        tty_path = GCSPRINTF("%s/serial/0/tty", dom_path);
+        break;
+    case LIBXL_CONSOLE_TYPE_PV:
+        if (cons_num == 0)
+            tty_path = GCSPRINTF("%s/console/tty", dom_path);
+        else
+            tty_path = GCSPRINTF("%s/device/console/%d/tty", dom_path,
+                                cons_num);
+        break;
+    default:
+        rc = ERROR_INVAL;
+        goto out;
+    }
+
+    tty = libxl__xs_read(gc, XBT_NULL, tty_path);
+    if (!tty) {
+       LOGE(ERROR,"unable to read console tty path `%s'",tty_path);
+       rc = ERROR_FAIL;
+       goto out;
+    }
+
+    *path = libxl__strdup(NOGC, tty);
+    rc = 0;
+out:
+    GC_FREE;
+    return rc;
+}
+
+static int libxl__primary_console_find(libxl_ctx *ctx, uint32_t domid_vm,
+                                       uint32_t *domid, int *cons_num,
+                                       libxl_console_type *type)
 {
     GC_INIT(ctx);
     uint32_t stubdomid = libxl_get_stubdom_id(ctx, domid_vm);
     int rc;
-    if (stubdomid)
-        rc = libxl_console_exec(ctx, stubdomid,
-                                STUBDOM_CONSOLE_SERIAL, LIBXL_CONSOLE_TYPE_PV);
-    else {
+
+    if (stubdomid) {
+        *domid = stubdomid;
+        *cons_num = STUBDOM_CONSOLE_SERIAL;
+        *type = LIBXL_CONSOLE_TYPE_PV;
+    } else {
         switch (libxl__domain_type(gc, domid_vm)) {
         case LIBXL_DOMAIN_TYPE_HVM:
-            rc = libxl_console_exec(ctx, domid_vm, 0, LIBXL_CONSOLE_TYPE_SERIAL);
+            *domid = domid_vm;
+            *cons_num = 0;
+            *type = LIBXL_CONSOLE_TYPE_SERIAL;
             break;
         case LIBXL_DOMAIN_TYPE_PV:
-            rc = libxl_console_exec(ctx, domid_vm, 0, LIBXL_CONSOLE_TYPE_PV);
+            *domid = domid_vm;
+            *cons_num = 0;
+            *type = LIBXL_CONSOLE_TYPE_PV;
             break;
         case -1:
-            LOG(ERROR,"unable to get domain type for domid=%"PRIu32,domid_vm);
-            rc = ERROR_FAIL;
+            LOG(ERROR,"unable to get domain type for domid=%"PRIu32, domid_vm);
+            rc = ERROR_INVAL;
+            goto out;
             break;
         default:
             abort();
         }
     }
+
+    rc = 0;
+out:
     GC_FREE;
     return rc;
 }
 
+int libxl_primary_console_exec(libxl_ctx *ctx, uint32_t domid_vm)
+{
+    uint32_t domid;
+    int cons_num;
+    libxl_console_type type;
+    int rc;
+
+    rc = libxl__primary_console_find(ctx, domid_vm, &domid, &cons_num, &type);
+    if ( rc ) return rc;
+    return libxl_console_exec(ctx, domid, cons_num, type);
+}
+
+int libxl_primary_console_get_tty(libxl_ctx *ctx, uint32_t domid_vm,
+                                  char **path)
+{
+    uint32_t domid;
+    int cons_num;
+    libxl_console_type type;
+    int rc;
+
+    rc = libxl__primary_console_find(ctx, domid_vm, &domid, &cons_num, &type);
+    if ( rc ) return rc;
+    return libxl_console_get_tty(ctx, domid, cons_num, type, path);
+}
+
 int libxl_vncviewer_exec(libxl_ctx *ctx, uint32_t domid, int autopass)
 {
     GC_INIT(ctx);

diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 53cba6fe77bc370341a906d5c37b22b39f9f6fe1..05f0e01df57d1ba2263d3620d0c8243b46c6911b 100644 (file)
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -570,6 +570,18 @@ int libxl_console_exec(libxl_ctx *ctx, uint32_t domid, int cons_num, libxl_conso
  * guests using pygrub. */
 int libxl_primary_console_exec(libxl_ctx *ctx, uint32_t domid_vm);
 
+/* libxl_console_get_tty retrieves the specified domain's console tty path
+ * and stores it in path. Caller is responsible for freeing the memory.
+ */
+int libxl_console_get_tty(libxl_ctx *ctx, uint32_t domid, int cons_num,
+                          libxl_console_type type, char **path);
+
+/* libxl_primary_console_get_tty retrieves the specified domain's primary
+ * console tty path and stores it in path. Caller is responsible for freeing
+ * the memory.
+ */
+int libxl_primary_console_get_tty(libxl_ctx *ctx, uint32_t domid_vm, char **path);
+
 /* May be called with info_r == NULL to check for domain's existance */
 int libxl_domain_info(libxl_ctx*, libxl_dominfo *info_r,
                       uint32_t domid);