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
vug_src_prepare(GSource * gsrc,gint * timeout)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
vug_src_check(GSource * gsrc)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
vug_src_dispatch(GSource * gsrc,GSourceFunc cb,gpointer data)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 GSource *
vug_source_new(VugDev * gdev,int fd,GIOCondition cond,vu_watch_cb vu_cb,gpointer data)72 vug_source_new(VugDev *gdev, int fd, GIOCondition cond,
73                vu_watch_cb vu_cb, gpointer data)
74 {
75     VuDev *dev = &gdev->parent;
76     GSource *gsrc;
77     VugSrc *src;
78     guint id;
79 
80     g_assert(gdev);
81     g_assert(fd >= 0);
82     g_assert(vu_cb);
83 
84     gsrc = g_source_new(&vug_src_funcs, sizeof(VugSrc));
85     g_source_set_callback(gsrc, (GSourceFunc)vu_cb, data, NULL);
86     src = (VugSrc *)gsrc;
87     src->dev = dev;
88     src->gfd.fd = fd;
89     src->gfd.events = cond;
90 
91     g_source_add_poll(gsrc, &src->gfd);
92     id = g_source_attach(gsrc, g_main_context_get_thread_default());
93     g_assert(id);
94 
95     return gsrc;
96 }
97 
98 static void
set_watch(VuDev * vu_dev,int fd,int vu_evt,vu_watch_cb cb,void * pvt)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(dev, fd, vu_evt, cb, pvt);
110     g_hash_table_replace(dev->fdmap, GINT_TO_POINTER(fd), src);
111 }
112 
113 static void
remove_watch(VuDev * vu_dev,int fd)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 
vug_watch(VuDev * dev,int condition,void * data)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 
vug_source_destroy(GSource * src)133 void vug_source_destroy(GSource *src)
134 {
135     if (!src) {
136         return;
137     }
138 
139     g_source_destroy(src);
140     g_source_unref(src);
141 }
142 
143 bool
vug_init(VugDev * dev,uint16_t max_queues,int socket,vu_panic_cb panic,const VuDevIface * iface)144 vug_init(VugDev *dev, uint16_t max_queues, int socket,
145          vu_panic_cb panic, const VuDevIface *iface)
146 {
147     g_assert(dev);
148     g_assert(iface);
149 
150     if (!vu_init(&dev->parent, max_queues, socket, panic, set_watch,
151                  remove_watch, iface)) {
152         return false;
153     }
154 
155     dev->fdmap = g_hash_table_new_full(NULL, NULL, NULL,
156                                        (GDestroyNotify) vug_source_destroy);
157 
158     dev->src = vug_source_new(dev, socket, G_IO_IN, vug_watch, NULL);
159 
160     return true;
161 }
162 
163 void
vug_deinit(VugDev * dev)164 vug_deinit(VugDev *dev)
165 {
166     g_assert(dev);
167 
168     g_hash_table_unref(dev->fdmap);
169     vug_source_destroy(dev->src);
170 }
171