contrib/libvhost-user/libvhost-user-glib.c

   1 /*
   2  * Vhost User library
   3  *
   4  * Copyright (c) 2016 Nutanix Inc. All rights reserved.
   5  * Copyright (c) 2017 Red Hat, Inc.
   6  *
   7  * Authors:
   8  *  Marc-André Lureau <mlureau@redhat.com>
   9  *  Felipe Franciosi <felipe@nutanix.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or
  12  * later.  See the COPYING file in the top-level directory.
  13  */
  14
  15 #include "qemu/osdep.h"
  16
  17 #include "libvhost-user-glib.h"
  18
  19 /* glib event loop integration for libvhost-user and misc callbacks */
  20
  21 G_STATIC_ASSERT((int)G_IO_IN == (int)VU_WATCH_IN);
  22 G_STATIC_ASSERT((int)G_IO_OUT == (int)VU_WATCH_OUT);
  23 G_STATIC_ASSERT((int)G_IO_PRI == (int)VU_WATCH_PRI);
  24 G_STATIC_ASSERT((int)G_IO_ERR == (int)VU_WATCH_ERR);
  25 G_STATIC_ASSERT((int)G_IO_HUP == (int)VU_WATCH_HUP);
  26
  27 typedef struct VugSrc {
  28     GSource parent;
  29     VuDev *dev;
  30     GPollFD gfd;
  31 } VugSrc;
  32
  33 static gboolean
  34 vug_src_prepare(GSource *gsrc, gint *timeout)
  35 {
  36     g_assert(timeout);
  37
  38     *timeout = -1;
  39     return FALSE;
  40 }
  41
  42 static gboolean
  43 vug_src_check(GSource *gsrc)
  44 {
  45     VugSrc *src = (VugSrc *)gsrc;
  46
  47     g_assert(src);
  48
  49     return src->gfd.revents & src->gfd.events;
  50 }
  51
  52 static gboolean
  53 vug_src_dispatch(GSource *gsrc, GSourceFunc cb, gpointer data)
  54 {
  55     VugSrc *src = (VugSrc *)gsrc;
  56
  57     g_assert(src);
  58
  59     ((vu_watch_cb)cb)(src->dev, src->gfd.revents, data);
  60
  61     return G_SOURCE_CONTINUE;
  62 }
  63
  64 static GSourceFuncs vug_src_funcs = {
  65     vug_src_prepare,
  66     vug_src_check,
  67     vug_src_dispatch,
  68     NULL
  69 };
  70
  71 static GSource *
  72 vug_source_new(VuDev *dev, int fd, GIOCondition cond,
  73                vu_watch_cb vu_cb, gpointer data)
  74 {
  75     GSource *gsrc;
  76     VugSrc *src;
  77     guint id;
  78
  79     g_assert(dev);
  80     g_assert(fd >= 0);
  81     g_assert(vu_cb);
  82
  83     gsrc = g_source_new(&vug_src_funcs, sizeof(VugSrc));
  84     g_source_set_callback(gsrc, (GSourceFunc)vu_cb, data, NULL);
  85     src = (VugSrc *)gsrc;
  86     src->dev = dev;
  87     src->gfd.fd = fd;
  88     src->gfd.events = cond;
  89
  90     g_source_add_poll(gsrc, &src->gfd);
  91     id = g_source_attach(gsrc, NULL);
  92     g_assert(id);
  93     g_source_unref(gsrc);
  94
  95     return gsrc;
  96 }
  97
  98 static void
  99 set_watch(VuDev *vu_dev, int fd, int vu_evt, vu_watch_cb cb, void *pvt)
 100 {
 101     GSource *src;
 102     VugDev *dev;
 103
 104     g_assert(vu_dev);
 105     g_assert(fd >= 0);
 106     g_assert(cb);
 107
 108     dev = container_of(vu_dev, VugDev, parent);
 109     src = vug_source_new(vu_dev, fd, vu_evt, cb, pvt);
 110     g_hash_table_replace(dev->fdmap, GINT_TO_POINTER(fd), src);
 111 }
 112
 113 static void
 114 remove_watch(VuDev *vu_dev, int fd)
 115 {
 116     VugDev *dev;
 117
 118     g_assert(vu_dev);
 119     g_assert(fd >= 0);
 120
 121     dev = container_of(vu_dev, VugDev, parent);
 122     g_hash_table_remove(dev->fdmap, GINT_TO_POINTER(fd));
 123 }
 124
 125
 126 static void vug_watch(VuDev *dev, int condition, void *data)
 127 {
 128     if (!vu_dispatch(dev) != 0) {
 129         dev->panic(dev, "Error processing vhost message");
 130     }
 131 }
 132
 133 void
 134 vug_init(VugDev *dev, int socket,
 135          vu_panic_cb panic, const VuDevIface *iface)
 136 {
 137     g_assert(dev);
 138     g_assert(iface);
 139
 140     vu_init(&dev->parent, socket, panic, set_watch, remove_watch, iface);
 141     dev->fdmap = g_hash_table_new_full(NULL, NULL, NULL,
 142                                        (GDestroyNotify) g_source_destroy);
 143
 144     dev->src = vug_source_new(&dev->parent, socket, G_IO_IN, vug_watch, NULL);
 145 }
 146
 147 void
 148 vug_deinit(VugDev *dev)
 149 {
 150     g_assert(dev);
 151
 152     g_hash_table_unref(dev->fdmap);
 153     g_source_unref(dev->src);
 154 }