[qemu.git] / hw / xen_console.c

/*
 *  Copyright (C) International Business Machines  Corp., 2005
 *  Author(s): Anthony Liguori <aliguori@us.ibm.com>
 *
 *  Copyright (C) Red Hat 2007
 *
 *  Xen Console
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; under version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/select.h>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>
#include <stdarg.h>
#include <sys/mman.h>
#include <xs.h>
#include <xen/io/console.h>
#include <xenctrl.h>

#include "hw.h"
#include "qemu-char.h"
#include "xen_backend.h"

struct buffer {
    uint8_t *data;
    size_t consumed;
    size_t size;
    size_t capacity;
    size_t max_capacity;
};

struct XenConsole {
    struct XenDevice  xendev;  /* must be first */
    struct buffer     buffer;
    char              console[XEN_BUFSIZE];
    int               ring_ref;
    void              *sring;
    CharDriverState   *chr;
    int               backlog;
};

static void buffer_append(struct XenConsole *con)
{
    struct buffer *buffer = &con->buffer;
    XENCONS_RING_IDX cons, prod, size;
    struct xencons_interface *intf = con->sring;

    cons = intf->out_cons;
    prod = intf->out_prod;
    xen_mb();

    size = prod - cons;
    if ((size == 0) || (size > sizeof(intf->out)))
	return;

    if ((buffer->capacity - buffer->size) < size) {
	buffer->capacity += (size + 1024);
	buffer->data = g_realloc(buffer->data, buffer->capacity);
    }

    while (cons != prod)
	buffer->data[buffer->size++] = intf->out[
	    MASK_XENCONS_IDX(cons++, intf->out)];

    xen_mb();
    intf->out_cons = cons;
    xen_be_send_notify(&con->xendev);

    if (buffer->max_capacity &&
	buffer->size > buffer->max_capacity) {
	/* Discard the middle of the data. */

	size_t over = buffer->size - buffer->max_capacity;
	uint8_t *maxpos = buffer->data + buffer->max_capacity;

	memmove(maxpos - over, maxpos, over);
	buffer->data = g_realloc(buffer->data, buffer->max_capacity);
	buffer->size = buffer->capacity = buffer->max_capacity;

	if (buffer->consumed > buffer->max_capacity - over)
	    buffer->consumed = buffer->max_capacity - over;
    }
}

static void buffer_advance(struct buffer *buffer, size_t len)
{
    buffer->consumed += len;
    if (buffer->consumed == buffer->size) {
	buffer->consumed = 0;
	buffer->size = 0;
    }
}

static int ring_free_bytes(struct XenConsole *con)
{
    struct xencons_interface *intf = con->sring;
    XENCONS_RING_IDX cons, prod, space;

    cons = intf->in_cons;
    prod = intf->in_prod;
    xen_mb();

    space = prod - cons;
    if (space > sizeof(intf->in))
	return 0; /* ring is screwed: ignore it */

    return (sizeof(intf->in) - space);
}

static int xencons_can_receive(void *opaque)
{
    struct XenConsole *con = opaque;
    return ring_free_bytes(con);
}

static void xencons_receive(void *opaque, const uint8_t *buf, int len)
{
    struct XenConsole *con = opaque;
    struct xencons_interface *intf = con->sring;
    XENCONS_RING_IDX prod;
    int i, max;

    max = ring_free_bytes(con);
    /* The can_receive() func limits this, but check again anyway */
    if (max < len)
	len = max;

    prod = intf->in_prod;
    for (i = 0; i < len; i++) {
	intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
	    buf[i];
    }
    xen_wmb();
    intf->in_prod = prod;
    xen_be_send_notify(&con->xendev);
}

static void xencons_send(struct XenConsole *con)
{
    ssize_t len, size;

    size = con->buffer.size - con->buffer.consumed;
    if (con->chr)
        len = qemu_chr_write(con->chr, con->buffer.data + con->buffer.consumed,
                             size);
    else
        len = size;
    if (len < 1) {
	if (!con->backlog) {
	    con->backlog = 1;
	    xen_be_printf(&con->xendev, 1, "backlog piling up, nobody listening?\n");
	}
    } else {
	buffer_advance(&con->buffer, len);
	if (con->backlog && len == size) {
	    con->backlog = 0;
	    xen_be_printf(&con->xendev, 1, "backlog is gone\n");
	}
    }
}

/* -------------------------------------------------------------------- */

static int con_init(struct XenDevice *xendev)
{
    struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
    char *type, *dom, label[32];
    int ret = 0;
    const char *output;

    /* setup */
    dom = xs_get_domain_path(xenstore, con->xendev.dom);
    snprintf(con->console, sizeof(con->console), "%s/console", dom);
    free(dom);

    type = xenstore_read_str(con->console, "type");
    if (!type || strcmp(type, "ioemu") != 0) {
	xen_be_printf(xendev, 1, "not for me (type=%s)\n", type);
        ret = -1;
        goto out;
    }

    output = xenstore_read_str(con->console, "output");

    /* no Xen override, use qemu output device */
    if (output == NULL) {
        con->chr = serial_hds[con->xendev.dev];
    } else {
        snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
        con->chr = qemu_chr_open(label, output, NULL);
    }

    xenstore_store_pv_console_info(con->xendev.dev, con->chr);

out:
    g_free(type);
    return ret;
}

static int con_connect(struct XenDevice *xendev)
{
    struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
    int limit;

    if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
	return -1;
    if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
	return -1;
    if (xenstore_read_int(con->console, "limit", &limit) == 0)
	con->buffer.max_capacity = limit;

    con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom,
				      XC_PAGE_SIZE,
				      PROT_READ|PROT_WRITE,
				      con->ring_ref);
    if (!con->sring)
	return -1;

    xen_be_bind_evtchn(&con->xendev);
    if (con->chr)
        qemu_chr_add_handlers(con->chr, xencons_can_receive, xencons_receive,
                              NULL, con);

    xen_be_printf(xendev, 1, "ring mfn %d, remote port %d, local port %d, limit %zd\n",
		  con->ring_ref,
		  con->xendev.remote_port,
		  con->xendev.local_port,
		  con->buffer.max_capacity);
    return 0;
}

static void con_disconnect(struct XenDevice *xendev)
{
    struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);

    if (con->chr)
        qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL);
    xen_be_unbind_evtchn(&con->xendev);

    if (con->sring) {
	munmap(con->sring, XC_PAGE_SIZE);
	con->sring = NULL;
    }
}

static void con_event(struct XenDevice *xendev)
{
    struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);

    buffer_append(con);
    if (con->buffer.size - con->buffer.consumed)
	xencons_send(con);
}

/* -------------------------------------------------------------------- */

struct XenDevOps xen_console_ops = {
    .size       = sizeof(struct XenConsole),
    .flags      = DEVOPS_FLAG_IGNORE_STATE,
    .init       = con_init,
    .connect    = con_connect,
    .event      = con_event,
    .disconnect = con_disconnect,
};
Commit	Line	Data
e57dd20b AL	1	/*
	2	* Copyright (C) International Business Machines Corp., 2005
	3	* Author(s): Anthony Liguori <aliguori@us.ibm.com>
	4	*
	5	* Copyright (C) Red Hat 2007
	6	*
	7	* Xen Console
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; under version 2 of the License.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License along
8167ee88	19	* with this program; if not, see <http://www.gnu.org/licenses/>.
e57dd20b AL	20	*/
	21
	22	#include <stdlib.h>
	23	#include <errno.h>
	24	#include <string.h>
	25	#include <sys/select.h>
	26	#include <fcntl.h>
	27	#include <unistd.h>
	28	#include <termios.h>
	29	#include <stdarg.h>
	30	#include <sys/mman.h>
	31	#include <xs.h>
	32	#include <xen/io/console.h>
	33	#include <xenctrl.h>
	34
	35	#include "hw.h"
e57dd20b AL	36	#include "qemu-char.h"
	37	#include "xen_backend.h"
	38
	39	struct buffer {
	40	uint8_t *data;
	41	size_t consumed;
	42	size_t size;
	43	size_t capacity;
	44	size_t max_capacity;
	45	};
	46
	47	struct XenConsole {
	48	struct XenDevice xendev; /* must be first */
	49	struct buffer buffer;
	50	char console[XEN_BUFSIZE];
	51	int ring_ref;
	52	void *sring;
	53	CharDriverState *chr;
	54	int backlog;
	55	};
	56
	57	static void buffer_append(struct XenConsole *con)
	58	{
	59	struct buffer *buffer = &con->buffer;
	60	XENCONS_RING_IDX cons, prod, size;
	61	struct xencons_interface *intf = con->sring;
	62
	63	cons = intf->out_cons;
	64	prod = intf->out_prod;
	65	xen_mb();
	66
	67	size = prod - cons;
	68	if ((size == 0) \|\| (size > sizeof(intf->out)))
	69	return;
	70
	71	if ((buffer->capacity - buffer->size) < size) {
	72	buffer->capacity += (size + 1024);
7267c094	73	buffer->data = g_realloc(buffer->data, buffer->capacity);
e57dd20b AL	74	}
	75
	76	while (cons != prod)
	77	buffer->data[buffer->size++] = intf->out[
	78	MASK_XENCONS_IDX(cons++, intf->out)];
	79
	80	xen_mb();
	81	intf->out_cons = cons;
	82	xen_be_send_notify(&con->xendev);
	83
	84	if (buffer->max_capacity &&
	85	buffer->size > buffer->max_capacity) {
	86	/* Discard the middle of the data. */
	87
	88	size_t over = buffer->size - buffer->max_capacity;
	89	uint8_t *maxpos = buffer->data + buffer->max_capacity;
	90
	91	memmove(maxpos - over, maxpos, over);
7267c094	92	buffer->data = g_realloc(buffer->data, buffer->max_capacity);
e57dd20b AL	93	buffer->size = buffer->capacity = buffer->max_capacity;
	94
	95	if (buffer->consumed > buffer->max_capacity - over)
	96	buffer->consumed = buffer->max_capacity - over;
	97	}
	98	}
	99
	100	static void buffer_advance(struct buffer *buffer, size_t len)
	101	{
	102	buffer->consumed += len;
	103	if (buffer->consumed == buffer->size) {
	104	buffer->consumed = 0;
	105	buffer->size = 0;
	106	}
	107	}
	108
	109	static int ring_free_bytes(struct XenConsole *con)
	110	{
	111	struct xencons_interface *intf = con->sring;
	112	XENCONS_RING_IDX cons, prod, space;
	113
	114	cons = intf->in_cons;
	115	prod = intf->in_prod;
	116	xen_mb();
	117
	118	space = prod - cons;
	119	if (space > sizeof(intf->in))
	120	return 0; /* ring is screwed: ignore it */
	121
	122	return (sizeof(intf->in) - space);
	123	}
	124
	125	static int xencons_can_receive(void *opaque)
	126	{
	127	struct XenConsole *con = opaque;
	128	return ring_free_bytes(con);
	129	}
	130
	131	static void xencons_receive(void opaque, const uint8_t buf, int len)
	132	{
	133	struct XenConsole *con = opaque;
	134	struct xencons_interface *intf = con->sring;
	135	XENCONS_RING_IDX prod;
	136	int i, max;
	137
	138	max = ring_free_bytes(con);
	139	/* The can_receive() func limits this, but check again anyway */
	140	if (max < len)
	141	len = max;
	142
	143	prod = intf->in_prod;
	144	for (i = 0; i < len; i++) {
	145	intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
	146	buf[i];
	147	}
	148	xen_wmb();
	149	intf->in_prod = prod;
	150	xen_be_send_notify(&con->xendev);
	151	}
	152
	153	static void xencons_send(struct XenConsole *con)
	154	{
	155	ssize_t len, size;
	156
157	size = con->buffer.size - con->buffer.consumed;
158	if (con->chr)
159	len = qemu_chr_write(con->chr, con->buffer.data + con->buffer.consumed,
160	size);
161	else
162	len = size;
163	if (len < 1) {
164	if (!con->backlog) {
165	con->backlog = 1;
166	xen_be_printf(&con->xendev, 1, "backlog piling up, nobody listening?\n");
167	}
168	} else {
169	buffer_advance(&con->buffer, len);
170	if (con->backlog && len == size) {
171	con->backlog = 0;
172	xen_be_printf(&con->xendev, 1, "backlog is gone\n");
173	}
174	}
175	}
176
177	/* -------------------------------------------------------------------- */
178
179	static int con_init(struct XenDevice *xendev)
180	{
181	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
0f51726a	182	char type, dom, label[32];
5e6b701a	183	int ret = 0;
0f51726a	184	const char *output;
e57dd20b AL	185
	186	/* setup */
	187	dom = xs_get_domain_path(xenstore, con->xendev.dom);
	188	snprintf(con->console, sizeof(con->console), "%s/console", dom);
	189	free(dom);
	190
	191	type = xenstore_read_str(con->console, "type");
96248fd8	192	if (!type \|\| strcmp(type, "ioemu") != 0) {
e57dd20b	193	xen_be_printf(xendev, 1, "not for me (type=%s)\n", type);
5e6b701a SS	194	ret = -1;
5e6b701a SS	195	goto out;
e57dd20b AL	196	}
e57dd20b AL	197
0f51726a	198	output = xenstore_read_str(con->console, "output");
25a11813 AG	199
25a11813 AG	200	/* no Xen override, use qemu output device */
0f51726a	201	if (output == NULL) {
25a11813 AG	202	con->chr = serial_hds[con->xendev.dev];
	203	} else {
	204	snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
	205	con->chr = qemu_chr_open(label, output, NULL);
0f51726a	206	}
25a11813	207
0f51726a	208	xenstore_store_pv_console_info(con->xendev.dev, con->chr);
e57dd20b	209
5e6b701a	210	out:
7267c094	211	g_free(type);
5e6b701a	212	return ret;
e57dd20b AL	213	}
	214
	215	static int con_connect(struct XenDevice *xendev)
	216	{
	217	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	218	int limit;
	219
	220	if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
	221	return -1;
	222	if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
	223	return -1;
	224	if (xenstore_read_int(con->console, "limit", &limit) == 0)
	225	con->buffer.max_capacity = limit;
	226
	227	con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom,
	228	XC_PAGE_SIZE,
	229	PROT_READ\|PROT_WRITE,
	230	con->ring_ref);
	231	if (!con->sring)
	232	return -1;
	233
	234	xen_be_bind_evtchn(&con->xendev);
	235	if (con->chr)
	236	qemu_chr_add_handlers(con->chr, xencons_can_receive, xencons_receive,
	237	NULL, con);
	238
	239	xen_be_printf(xendev, 1, "ring mfn %d, remote port %d, local port %d, limit %zd\n",
	240	con->ring_ref,
	241	con->xendev.remote_port,
	242	con->xendev.local_port,
	243	con->buffer.max_capacity);
	244	return 0;
	245	}
	246
	247	static void con_disconnect(struct XenDevice *xendev)
	248	{
	249	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	250
	251	if (con->chr)
	252	qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL);
	253	xen_be_unbind_evtchn(&con->xendev);
	254
	255	if (con->sring) {
	256	munmap(con->sring, XC_PAGE_SIZE);
	257	con->sring = NULL;
	258	}
	259	}
	260
	261	static void con_event(struct XenDevice *xendev)
	262	{
	263	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	264
	265	buffer_append(con);
	266	if (con->buffer.size - con->buffer.consumed)
	267	xencons_send(con);
	268	}
	269
	270	/* -------------------------------------------------------------------- */
	271
	272	struct XenDevOps xen_console_ops = {
	273	.size = sizeof(struct XenConsole),
	274	.flags = DEVOPS_FLAG_IGNORE_STATE,
	275	.init = con_init,
	276	.connect = con_connect,
277	.event = con_event,
278	.disconnect = con_disconnect,
279	};