libvhost-user: add glib source helper

This file implements a bridge from the vu_init API of libvhost-user to
GSource, so that libvhost-user can be used inside a GLib main loop.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Marc-André Lureau 2017-08-17 20:55:14 +02:00
parent 422a26872e
commit 8bb7ddb78a
3 changed files with 187 additions and 1 deletions

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@ -1 +1 @@
libvhost-user-obj-y = libvhost-user.o
libvhost-user-obj-y += libvhost-user.o libvhost-user-glib.o

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/*
* Vhost User library
*
* Copyright (c) 2016 Nutanix Inc. All rights reserved.
* Copyright (c) 2017 Red Hat, Inc.
*
* Authors:
* Marc-André Lureau <mlureau@redhat.com>
* Felipe Franciosi <felipe@nutanix.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "libvhost-user-glib.h"
/* glib event loop integration for libvhost-user and misc callbacks */
G_STATIC_ASSERT((int)G_IO_IN == (int)VU_WATCH_IN);
G_STATIC_ASSERT((int)G_IO_OUT == (int)VU_WATCH_OUT);
G_STATIC_ASSERT((int)G_IO_PRI == (int)VU_WATCH_PRI);
G_STATIC_ASSERT((int)G_IO_ERR == (int)VU_WATCH_ERR);
G_STATIC_ASSERT((int)G_IO_HUP == (int)VU_WATCH_HUP);
typedef struct VugSrc {
GSource parent;
VuDev *dev;
GPollFD gfd;
} VugSrc;
static gboolean
vug_src_prepare(GSource *gsrc, gint *timeout)
{
g_assert(timeout);
*timeout = -1;
return FALSE;
}
static gboolean
vug_src_check(GSource *gsrc)
{
VugSrc *src = (VugSrc *)gsrc;
g_assert(src);
return src->gfd.revents & src->gfd.events;
}
static gboolean
vug_src_dispatch(GSource *gsrc, GSourceFunc cb, gpointer data)
{
VugSrc *src = (VugSrc *)gsrc;
g_assert(src);
((vu_watch_cb)cb)(src->dev, src->gfd.revents, data);
return G_SOURCE_CONTINUE;
}
static GSourceFuncs vug_src_funcs = {
vug_src_prepare,
vug_src_check,
vug_src_dispatch,
NULL
};
static GSource *
vug_source_new(VuDev *dev, int fd, GIOCondition cond,
vu_watch_cb vu_cb, gpointer data)
{
GSource *gsrc;
VugSrc *src;
guint id;
g_assert(dev);
g_assert(fd >= 0);
g_assert(vu_cb);
gsrc = g_source_new(&vug_src_funcs, sizeof(VugSrc));
g_source_set_callback(gsrc, (GSourceFunc)vu_cb, data, NULL);
src = (VugSrc *)gsrc;
src->dev = dev;
src->gfd.fd = fd;
src->gfd.events = cond;
g_source_add_poll(gsrc, &src->gfd);
id = g_source_attach(gsrc, NULL);
g_assert(id);
g_source_unref(gsrc);
return gsrc;
}
static void
set_watch(VuDev *vu_dev, int fd, int vu_evt, vu_watch_cb cb, void *pvt)
{
GSource *src;
VugDev *dev;
g_assert(vu_dev);
g_assert(fd >= 0);
g_assert(cb);
dev = container_of(vu_dev, VugDev, parent);
src = vug_source_new(vu_dev, fd, vu_evt, cb, pvt);
g_hash_table_replace(dev->fdmap, GINT_TO_POINTER(fd), src);
}
static void
remove_watch(VuDev *vu_dev, int fd)
{
VugDev *dev;
g_assert(vu_dev);
g_assert(fd >= 0);
dev = container_of(vu_dev, VugDev, parent);
g_hash_table_remove(dev->fdmap, GINT_TO_POINTER(fd));
}
static void vug_watch(VuDev *dev, int condition, void *data)
{
if (!vu_dispatch(dev) != 0) {
dev->panic(dev, "Error processing vhost message");
}
}
void
vug_init(VugDev *dev, int socket,
vu_panic_cb panic, const VuDevIface *iface)
{
g_assert(dev);
g_assert(iface);
vu_init(&dev->parent, socket, panic, set_watch, remove_watch, iface);
dev->fdmap = g_hash_table_new_full(NULL, NULL, NULL,
(GDestroyNotify) g_source_destroy);
dev->src = vug_source_new(&dev->parent, socket, G_IO_IN, vug_watch, NULL);
}
void
vug_deinit(VugDev *dev)
{
g_assert(dev);
g_hash_table_unref(dev->fdmap);
g_source_unref(dev->src);
}

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/*
* Vhost User library
*
* Copyright (c) 2016 Nutanix Inc. All rights reserved.
* Copyright (c) 2017 Red Hat, Inc.
*
* Authors:
* Marc-André Lureau <mlureau@redhat.com>
* Felipe Franciosi <felipe@nutanix.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#ifndef LIBVHOST_USER_GLIB_H
#define LIBVHOST_USER_GLIB_H
#include <glib.h>
#include "libvhost-user.h"
typedef struct VugDev {
VuDev parent;
GHashTable *fdmap; /* fd -> gsource */
GSource *src;
} VugDev;
void vug_init(VugDev *dev, int socket,
vu_panic_cb panic, const VuDevIface *iface);
void vug_deinit(VugDev *dev);
#endif /* LIBVHOST_USER_GLIB_H */