subprojects/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 "libvhost-user-glib.h"
  16
  17 #ifndef container_of
  18 #define container_of(ptr, type, member)              \
  19     __extension__({                                  \
  20         void *__mptr = (void *)(ptr);                \
  21         ((type *)(__mptr - offsetof(type, member))); \
  22     })
  23 #endif
  24
  25 /* glib event loop integration for libvhost-user and misc callbacks */
  26
  27 G_STATIC_ASSERT((int)G_IO_IN == (int)VU_WATCH_IN);
  28 G_STATIC_ASSERT((int)G_IO_OUT == (int)VU_WATCH_OUT);
  29 G_STATIC_ASSERT((int)G_IO_PRI == (int)VU_WATCH_PRI);
  30 G_STATIC_ASSERT((int)G_IO_ERR == (int)VU_WATCH_ERR);
  31 G_STATIC_ASSERT((int)G_IO_HUP == (int)VU_WATCH_HUP);
  32
  33 typedef struct VugSrc {
  34     GSource parent;
  35     VuDev *dev;
  36     GPollFD gfd;
  37 } VugSrc;
  38
  39 static gboolean
  40 vug_src_prepare(GSource *gsrc, gint *timeout)
  41 {
  42     g_assert(timeout);
  43
  44     *timeout = -1;
  45     return FALSE;
  46 }
  47
  48 static gboolean
  49 vug_src_check(GSource *gsrc)
  50 {
  51     VugSrc *src = (VugSrc *)gsrc;
  52
  53     g_assert(src);
  54
  55     return src->gfd.revents & src->gfd.events;
  56 }
  57
  58 static gboolean
  59 vug_src_dispatch(GSource *gsrc, GSourceFunc cb, gpointer data)
  60 {
  61     VugSrc *src = (VugSrc *)gsrc;
  62
  63     g_assert(src);
  64
  65     ((vu_watch_cb)cb)(src->dev, src->gfd.revents, data);
  66
  67     return G_SOURCE_CONTINUE;
  68 }
  69
  70 static GSourceFuncs vug_src_funcs = {
  71     vug_src_prepare,
  72     vug_src_check,
  73     vug_src_dispatch,
  74     NULL
  75 };
  76
  77 GSource *
  78 vug_source_new(VugDev *gdev, int fd, GIOCondition cond,
  79                vu_watch_cb vu_cb, gpointer data)
  80 {
  81     VuDev *dev = &gdev->parent;
  82     GSource *gsrc;
  83     VugSrc *src;
  84     guint id;
  85
  86     g_assert(gdev);
  87     g_assert(fd >= 0);
  88     g_assert(vu_cb);
  89
  90     gsrc = g_source_new(&vug_src_funcs, sizeof(VugSrc));
  91     g_source_set_callback(gsrc, (GSourceFunc)vu_cb, data, NULL);
  92     src = (VugSrc *)gsrc;
  93     src->dev = dev;
  94     src->gfd.fd = fd;
  95     src->gfd.events = cond;
  96
  97     g_source_add_poll(gsrc, &src->gfd);
  98     id = g_source_attach(gsrc, g_main_context_get_thread_default());
  99     g_assert(id);
 100
 101     return gsrc;
 102 }
 103
 104 static void
 105 set_watch(VuDev *vu_dev, int fd, int vu_evt, vu_watch_cb cb, void *pvt)
 106 {
 107     GSource *src;
 108     VugDev *dev;
 109
 110     g_assert(vu_dev);
 111     g_assert(fd >= 0);
 112     g_assert(cb);
 113
 114     dev = container_of(vu_dev, VugDev, parent);
 115     src = vug_source_new(dev, fd, vu_evt, cb, pvt);
 116     g_hash_table_replace(dev->fdmap, GINT_TO_POINTER(fd), src);
 117 }
 118
 119 static void
 120 remove_watch(VuDev *vu_dev, int fd)
 121 {
 122     VugDev *dev;
 123
 124     g_assert(vu_dev);
 125     g_assert(fd >= 0);
 126
 127     dev = container_of(vu_dev, VugDev, parent);
 128     g_hash_table_remove(dev->fdmap, GINT_TO_POINTER(fd));
 129 }
 130
 131
 132 static void vug_watch(VuDev *dev, int condition, void *data)
 133 {
 134     if (!vu_dispatch(dev) != 0) {
 135         dev->panic(dev, "Error processing vhost message");
 136     }
 137 }
 138
 139 void vug_source_destroy(GSource *src)
 140 {
 141     if (!src) {
 142         return;
 143     }
 144
 145     g_source_destroy(src);
 146     g_source_unref(src);
 147 }
 148
 149 bool
 150 vug_init(VugDev *dev, uint16_t max_queues, int socket,
 151          vu_panic_cb panic, const VuDevIface *iface)
 152 {
 153     g_assert(dev);
 154     g_assert(iface);
 155
 156     if (!vu_init(&dev->parent, max_queues, socket, panic, NULL, set_watch,
 157                  remove_watch, iface)) {
 158         return false;
 159     }
 160
 161     dev->fdmap = g_hash_table_new_full(NULL, NULL, NULL,
 162                                        (GDestroyNotify) vug_source_destroy);
 163
 164     dev->src = vug_source_new(dev, socket, G_IO_IN, vug_watch, NULL);
 165
 166     return true;
 167 }
 168
 169 void
 170 vug_deinit(VugDev *dev)
 171 {
 172     g_assert(dev);
 173
 174     g_hash_table_unref(dev->fdmap);
 175     vug_source_destroy(dev->src);
 176 }