guest_channel.c revision 809f0800
1/*-
2 *   BSD LICENSE
3 *
4 *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
5 *   All rights reserved.
6 *
7 *   Redistribution and use in source and binary forms, with or without
8 *   modification, are permitted provided that the following conditions
9 *   are met:
10 *
11 *     * Redistributions of source code must retain the above copyright
12 *       notice, this list of conditions and the following disclaimer.
13 *     * Redistributions in binary form must reproduce the above copyright
14 *       notice, this list of conditions and the following disclaimer in
15 *       the documentation and/or other materials provided with the
16 *       distribution.
17 *     * Neither the name of Intel Corporation nor the names of its
18 *       contributors may be used to endorse or promote products derived
19 *       from this software without specific prior written permission.
20 *
21 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <stdio.h>
35#include <stdlib.h>
36#include <unistd.h>
37#include <signal.h>
38#include <limits.h>
39#include <fcntl.h>
40#include <string.h>
41#include <errno.h>
42
43
44#include <rte_log.h>
45
46#include "guest_channel.h"
47#include "channel_commands.h"
48
49#define RTE_LOGTYPE_GUEST_CHANNEL RTE_LOGTYPE_USER1
50
51static int global_fds[RTE_MAX_LCORE];
52
53int
54guest_channel_host_connect(const char *path, unsigned lcore_id)
55{
56	int flags, ret;
57	struct channel_packet pkt;
58	char fd_path[PATH_MAX];
59	int fd = -1;
60
61	if (lcore_id >= RTE_MAX_LCORE) {
62		RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is out of range 0...%d\n",
63				lcore_id, RTE_MAX_LCORE-1);
64		return -1;
65	}
66	/* check if path is already open */
67	if (global_fds[lcore_id] != 0) {
68		RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is already open with fd %d\n",
69				lcore_id, global_fds[lcore_id]);
70		return -1;
71	}
72
73	snprintf(fd_path, PATH_MAX, "%s.%u", path, lcore_id);
74	RTE_LOG(INFO, GUEST_CHANNEL, "Opening channel '%s' for lcore %u\n",
75			fd_path, lcore_id);
76	fd = open(fd_path, O_RDWR);
77	if (fd < 0) {
78		RTE_LOG(ERR, GUEST_CHANNEL, "Unable to to connect to '%s' with error "
79				"%s\n", fd_path, strerror(errno));
80		return -1;
81	}
82
83	flags = fcntl(fd, F_GETFL, 0);
84	if (flags < 0) {
85		RTE_LOG(ERR, GUEST_CHANNEL, "Failed on fcntl get flags for file %s\n",
86				fd_path);
87		goto error;
88	}
89
90	flags |= O_NONBLOCK;
91	if (fcntl(fd, F_SETFL, flags) < 0) {
92		RTE_LOG(ERR, GUEST_CHANNEL, "Failed on setting non-blocking mode for "
93				"file %s", fd_path);
94		goto error;
95	}
96	/* QEMU needs a delay after connection */
97	sleep(1);
98
99	/* Send a test packet, this command is ignored by the host, but a successful
100	 * send indicates that the host endpoint is monitoring.
101	 */
102	pkt.command = CPU_POWER_CONNECT;
103	global_fds[lcore_id] = fd;
104	ret = guest_channel_send_msg(&pkt, lcore_id);
105	if (ret != 0) {
106		RTE_LOG(ERR, GUEST_CHANNEL,
107				"Error on channel '%s' communications test: %s\n",
108				fd_path, ret > 0 ? strerror(ret) :
109				"channel not connected");
110		goto error;
111	}
112	RTE_LOG(INFO, GUEST_CHANNEL, "Channel '%s' is now connected\n", fd_path);
113	return 0;
114error:
115	close(fd);
116	global_fds[lcore_id] = 0;
117	return -1;
118}
119
120int
121guest_channel_send_msg(struct channel_packet *pkt, unsigned lcore_id)
122{
123	int ret, buffer_len = sizeof(*pkt);
124	void *buffer = pkt;
125
126	if (lcore_id >= RTE_MAX_LCORE) {
127		RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is out of range 0...%d\n",
128				lcore_id, RTE_MAX_LCORE-1);
129		return -1;
130	}
131
132	if (global_fds[lcore_id] == 0) {
133		RTE_LOG(ERR, GUEST_CHANNEL, "Channel is not connected\n");
134		return -1;
135	}
136	while (buffer_len > 0) {
137		ret = write(global_fds[lcore_id], buffer, buffer_len);
138		if (ret == buffer_len)
139			return 0;
140		if (ret == -1) {
141			if (errno == EINTR)
142				continue;
143			return errno;
144		}
145		buffer = (char *)buffer + ret;
146		buffer_len -= ret;
147	}
148	return 0;
149}
150
151void
152guest_channel_host_disconnect(unsigned lcore_id)
153{
154	if (lcore_id >= RTE_MAX_LCORE) {
155		RTE_LOG(ERR, GUEST_CHANNEL, "Channel(%u) is out of range 0...%d\n",
156				lcore_id, RTE_MAX_LCORE-1);
157		return;
158	}
159	if (global_fds[lcore_id] == 0)
160		return;
161	close(global_fds[lcore_id]);
162	global_fds[lcore_id] = 0;
163}
164