[qemu.git] / hw / xen_console.c

/*
 *  Copyright (C) International Business Machines  Corp., 2005
 *  Author(s): Anthony Liguori <[email protected]>
 *
 *  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 "hw.h"
#include "qemu-char.h"
#include "xen_backend.h"

#include <xen/io/console.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_fe_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_new(label, output, NULL);
    }

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

out:
    g_free(type);
    return ret;
}

static int con_initialise(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 (!xendev->dev) {
        return;
    }
    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,
    .initialise = con_initialise,
    .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 <[email protected]>
	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>
e57dd20b AL	31
e57dd20b AL	32	#include "hw.h"
e57dd20b AL	33	#include "qemu-char.h"
	34	#include "xen_backend.h"
	35
b41f6719 AP	36	#include <xen/io/console.h>
b41f6719 AP	37
e57dd20b AL	38	struct buffer {
	39	uint8_t *data;
	40	size_t consumed;
	41	size_t size;
	42	size_t capacity;
	43	size_t max_capacity;
	44	};
	45
	46	struct XenConsole {
	47	struct XenDevice xendev; /* must be first */
	48	struct buffer buffer;
	49	char console[XEN_BUFSIZE];
	50	int ring_ref;
	51	void *sring;
	52	CharDriverState *chr;
	53	int backlog;
	54	};
	55
	56	static void buffer_append(struct XenConsole *con)
	57	{
	58	struct buffer *buffer = &con->buffer;
	59	XENCONS_RING_IDX cons, prod, size;
	60	struct xencons_interface *intf = con->sring;
	61
	62	cons = intf->out_cons;
	63	prod = intf->out_prod;
	64	xen_mb();
	65
	66	size = prod - cons;
	67	if ((size == 0) \|\| (size > sizeof(intf->out)))
	68	return;
	69
	70	if ((buffer->capacity - buffer->size) < size) {
	71	buffer->capacity += (size + 1024);
7267c094	72	buffer->data = g_realloc(buffer->data, buffer->capacity);
e57dd20b AL	73	}
	74
	75	while (cons != prod)
	76	buffer->data[buffer->size++] = intf->out[
	77	MASK_XENCONS_IDX(cons++, intf->out)];
	78
	79	xen_mb();
	80	intf->out_cons = cons;
	81	xen_be_send_notify(&con->xendev);
	82
	83	if (buffer->max_capacity &&
	84	buffer->size > buffer->max_capacity) {
	85	/* Discard the middle of the data. */
	86
	87	size_t over = buffer->size - buffer->max_capacity;
	88	uint8_t *maxpos = buffer->data + buffer->max_capacity;
	89
	90	memmove(maxpos - over, maxpos, over);
7267c094	91	buffer->data = g_realloc(buffer->data, buffer->max_capacity);
e57dd20b AL	92	buffer->size = buffer->capacity = buffer->max_capacity;
	93
	94	if (buffer->consumed > buffer->max_capacity - over)
	95	buffer->consumed = buffer->max_capacity - over;
	96	}
	97	}
	98
	99	static void buffer_advance(struct buffer *buffer, size_t len)
	100	{
	101	buffer->consumed += len;
	102	if (buffer->consumed == buffer->size) {
	103	buffer->consumed = 0;
	104	buffer->size = 0;
	105	}
	106	}
	107
	108	static int ring_free_bytes(struct XenConsole *con)
	109	{
	110	struct xencons_interface *intf = con->sring;
	111	XENCONS_RING_IDX cons, prod, space;
	112
	113	cons = intf->in_cons;
	114	prod = intf->in_prod;
	115	xen_mb();
	116
	117	space = prod - cons;
	118	if (space > sizeof(intf->in))
	119	return 0; /* ring is screwed: ignore it */
	120
	121	return (sizeof(intf->in) - space);
	122	}
	123
	124	static int xencons_can_receive(void *opaque)
	125	{
	126	struct XenConsole *con = opaque;
	127	return ring_free_bytes(con);
	128	}
	129
	130	static void xencons_receive(void opaque, const uint8_t buf, int len)
	131	{
	132	struct XenConsole *con = opaque;
	133	struct xencons_interface *intf = con->sring;
	134	XENCONS_RING_IDX prod;
	135	int i, max;
	136
	137	max = ring_free_bytes(con);
	138	/* The can_receive() func limits this, but check again anyway */
	139	if (max < len)
	140	len = max;
	141
	142	prod = intf->in_prod;
	143	for (i = 0; i < len; i++) {
	144	intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
	145	buf[i];
	146	}
	147	xen_wmb();
	148	intf->in_prod = prod;
	149	xen_be_send_notify(&con->xendev);
	150	}
	151
	152	static void xencons_send(struct XenConsole *con)
	153	{
	154	ssize_t len, size;
	155
156	size = con->buffer.size - con->buffer.consumed;
157	if (con->chr)
2cc6e0a1	158	len = qemu_chr_fe_write(con->chr, con->buffer.data + con->buffer.consumed,
e57dd20b AL	159	size);
	160	else
	161	len = size;
	162	if (len < 1) {
	163	if (!con->backlog) {
	164	con->backlog = 1;
	165	xen_be_printf(&con->xendev, 1, "backlog piling up, nobody listening?\n");
	166	}
	167	} else {
	168	buffer_advance(&con->buffer, len);
	169	if (con->backlog && len == size) {
	170	con->backlog = 0;
	171	xen_be_printf(&con->xendev, 1, "backlog is gone\n");
	172	}
	173	}
	174	}
	175
	176	/* -------------------------------------------------------------------- */
	177
	178	static int con_init(struct XenDevice *xendev)
	179	{
	180	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
0f51726a	181	char type, dom, label[32];
5e6b701a	182	int ret = 0;
0f51726a	183	const char *output;
e57dd20b AL	184
	185	/* setup */
	186	dom = xs_get_domain_path(xenstore, con->xendev.dom);
	187	snprintf(con->console, sizeof(con->console), "%s/console", dom);
	188	free(dom);
	189
	190	type = xenstore_read_str(con->console, "type");
96248fd8	191	if (!type \|\| strcmp(type, "ioemu") != 0) {
e57dd20b	192	xen_be_printf(xendev, 1, "not for me (type=%s)\n", type);
5e6b701a SS	193	ret = -1;
5e6b701a SS	194	goto out;
e57dd20b AL	195	}
e57dd20b AL	196
0f51726a	197	output = xenstore_read_str(con->console, "output");
25a11813 AG	198
25a11813 AG	199	/* no Xen override, use qemu output device */
0f51726a	200	if (output == NULL) {
25a11813 AG	201	con->chr = serial_hds[con->xendev.dev];
	202	} else {
	203	snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
27143a44	204	con->chr = qemu_chr_new(label, output, NULL);
0f51726a	205	}
25a11813	206
0f51726a	207	xenstore_store_pv_console_info(con->xendev.dev, con->chr);
e57dd20b	208
5e6b701a	209	out:
7267c094	210	g_free(type);
5e6b701a	211	return ret;
e57dd20b AL	212	}
e57dd20b AL	213
384087b2	214	static int con_initialise(struct XenDevice *xendev)
e57dd20b AL	215	{
	216	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	217	int limit;
	218
	219	if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
	220	return -1;
	221	if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
	222	return -1;
	223	if (xenstore_read_int(con->console, "limit", &limit) == 0)
	224	con->buffer.max_capacity = limit;
	225
	226	con->sring = xc_map_foreign_range(xen_xc, con->xendev.dom,
	227	XC_PAGE_SIZE,
	228	PROT_READ\|PROT_WRITE,
	229	con->ring_ref);
	230	if (!con->sring)
	231	return -1;
	232
	233	xen_be_bind_evtchn(&con->xendev);
	234	if (con->chr)
	235	qemu_chr_add_handlers(con->chr, xencons_can_receive, xencons_receive,
	236	NULL, con);
	237
	238	xen_be_printf(xendev, 1, "ring mfn %d, remote port %d, local port %d, limit %zd\n",
	239	con->ring_ref,
	240	con->xendev.remote_port,
	241	con->xendev.local_port,
	242	con->buffer.max_capacity);
	243	return 0;
	244	}
	245
	246	static void con_disconnect(struct XenDevice *xendev)
	247	{
	248	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	249
028c85f0 SS	250	if (!xendev->dev) {
	251	return;
	252	}
e57dd20b AL	253	if (con->chr)
	254	qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL);
	255	xen_be_unbind_evtchn(&con->xendev);
	256
	257	if (con->sring) {
	258	munmap(con->sring, XC_PAGE_SIZE);
	259	con->sring = NULL;
	260	}
	261	}
	262
	263	static void con_event(struct XenDevice *xendev)
	264	{
	265	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	266
	267	buffer_append(con);
	268	if (con->buffer.size - con->buffer.consumed)
	269	xencons_send(con);
	270	}
	271
	272	/* -------------------------------------------------------------------- */
	273
	274	struct XenDevOps xen_console_ops = {
	275	.size = sizeof(struct XenConsole),
	276	.flags = DEVOPS_FLAG_IGNORE_STATE,
	277	.init = con_init,
384087b2	278	.initialise = con_initialise,
e57dd20b AL	279	.event = con_event,
	280	.disconnect = con_disconnect,
	281	};