[qemu.git] / hw / char / 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 "qemu/osdep.h"
#include <sys/select.h>
#include <termios.h>

#include "hw/hw.h"
#include "sysemu/char.h"
#include "hw/xen/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);
    if (!xendev->dev) {
        snprintf(con->console, sizeof(con->console), "%s/console", dom);
    } else {
        snprintf(con->console, sizeof(con->console), "%s/device/console/%d", dom, xendev->dev);
    }
    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;

    if (!xendev->dev) {
        xen_pfn_t mfn = con->ring_ref;
        con->sring = xenforeignmemory_map(xen_fmem, con->xendev.dom,
                                          PROT_READ|PROT_WRITE,
                                          1, &mfn, NULL);
    } else {
        con->sring = xengnttab_map_grant_ref(xendev->gnttabdev, con->xendev.dom,
                                             con->ring_ref,
                                             PROT_READ|PROT_WRITE);
    }
    if (!con->sring)
	return -1;

    xen_be_bind_evtchn(&con->xendev);
    if (con->chr) {
        if (qemu_chr_fe_claim(con->chr) == 0) {
            qemu_chr_add_handlers(con->chr, xencons_can_receive,
                                  xencons_receive, NULL, con);
        } else {
            xen_be_printf(xendev, 0,
                          "xen_console_init error chardev %s already used\n",
                          con->chr->label);
            con->chr = NULL;
        }
    }

    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);
        qemu_chr_fe_release(con->chr);
    }
    xen_be_unbind_evtchn(&con->xendev);

    if (con->sring) {
        if (!xendev->dev) {
            xenforeignmemory_unmap(xen_fmem, con->sring, 1);
        } else {
            xengnttab_unmap(xendev->gnttabdev, con->sring, 1);
        }
        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|DEVOPS_FLAG_NEED_GNTDEV,
    .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	*/
e57dd20b AL	21
21cbfe5f	22	#include "qemu/osdep.h"
e57dd20b	23	#include <sys/select.h>
e57dd20b	24	#include <termios.h>
e57dd20b	25
83c9f4ca	26	#include "hw/hw.h"
dccfcd0e	27	#include "sysemu/char.h"
0d09e41a	28	#include "hw/xen/xen_backend.h"
e57dd20b	29
b41f6719 AP	30	#include <xen/io/console.h>
b41f6719 AP	31
e57dd20b AL	32	struct buffer {
	33	uint8_t *data;
	34	size_t consumed;
	35	size_t size;
	36	size_t capacity;
	37	size_t max_capacity;
	38	};
	39
	40	struct XenConsole {
	41	struct XenDevice xendev; /* must be first */
	42	struct buffer buffer;
	43	char console[XEN_BUFSIZE];
	44	int ring_ref;
	45	void *sring;
	46	CharDriverState *chr;
	47	int backlog;
	48	};
	49
	50	static void buffer_append(struct XenConsole *con)
	51	{
	52	struct buffer *buffer = &con->buffer;
	53	XENCONS_RING_IDX cons, prod, size;
	54	struct xencons_interface *intf = con->sring;
	55
	56	cons = intf->out_cons;
	57	prod = intf->out_prod;
	58	xen_mb();
	59
	60	size = prod - cons;
	61	if ((size == 0) \|\| (size > sizeof(intf->out)))
	62	return;
	63
	64	if ((buffer->capacity - buffer->size) < size) {
	65	buffer->capacity += (size + 1024);
7267c094	66	buffer->data = g_realloc(buffer->data, buffer->capacity);
e57dd20b AL	67	}
	68
	69	while (cons != prod)
	70	buffer->data[buffer->size++] = intf->out[
	71	MASK_XENCONS_IDX(cons++, intf->out)];
	72
	73	xen_mb();
	74	intf->out_cons = cons;
	75	xen_be_send_notify(&con->xendev);
	76
	77	if (buffer->max_capacity &&
	78	buffer->size > buffer->max_capacity) {
	79	/* Discard the middle of the data. */
	80
	81	size_t over = buffer->size - buffer->max_capacity;
	82	uint8_t *maxpos = buffer->data + buffer->max_capacity;
	83
	84	memmove(maxpos - over, maxpos, over);
7267c094	85	buffer->data = g_realloc(buffer->data, buffer->max_capacity);
e57dd20b AL	86	buffer->size = buffer->capacity = buffer->max_capacity;
	87
	88	if (buffer->consumed > buffer->max_capacity - over)
	89	buffer->consumed = buffer->max_capacity - over;
	90	}
	91	}
	92
	93	static void buffer_advance(struct buffer *buffer, size_t len)
	94	{
	95	buffer->consumed += len;
	96	if (buffer->consumed == buffer->size) {
	97	buffer->consumed = 0;
	98	buffer->size = 0;
	99	}
	100	}
	101
	102	static int ring_free_bytes(struct XenConsole *con)
	103	{
	104	struct xencons_interface *intf = con->sring;
	105	XENCONS_RING_IDX cons, prod, space;
	106
	107	cons = intf->in_cons;
	108	prod = intf->in_prod;
	109	xen_mb();
	110
	111	space = prod - cons;
	112	if (space > sizeof(intf->in))
	113	return 0; /* ring is screwed: ignore it */
	114
	115	return (sizeof(intf->in) - space);
	116	}
	117
	118	static int xencons_can_receive(void *opaque)
	119	{
	120	struct XenConsole *con = opaque;
	121	return ring_free_bytes(con);
	122	}
	123
	124	static void xencons_receive(void opaque, const uint8_t buf, int len)
	125	{
	126	struct XenConsole *con = opaque;
	127	struct xencons_interface *intf = con->sring;
	128	XENCONS_RING_IDX prod;
	129	int i, max;
	130
	131	max = ring_free_bytes(con);
	132	/* The can_receive() func limits this, but check again anyway */
	133	if (max < len)
	134	len = max;
	135
	136	prod = intf->in_prod;
	137	for (i = 0; i < len; i++) {
	138	intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
	139	buf[i];
	140	}
	141	xen_wmb();
	142	intf->in_prod = prod;
	143	xen_be_send_notify(&con->xendev);
	144	}
	145
	146	static void xencons_send(struct XenConsole *con)
	147	{
	148	ssize_t len, size;
	149
150	size = con->buffer.size - con->buffer.consumed;
151	if (con->chr)
2cc6e0a1	152	len = qemu_chr_fe_write(con->chr, con->buffer.data + con->buffer.consumed,
e57dd20b AL	153	size);
	154	else
	155	len = size;
	156	if (len < 1) {
	157	if (!con->backlog) {
	158	con->backlog = 1;
	159	xen_be_printf(&con->xendev, 1, "backlog piling up, nobody listening?\n");
	160	}
	161	} else {
	162	buffer_advance(&con->buffer, len);
	163	if (con->backlog && len == size) {
	164	con->backlog = 0;
	165	xen_be_printf(&con->xendev, 1, "backlog is gone\n");
	166	}
	167	}
	168	}
	169
	170	/* -------------------------------------------------------------------- */
	171
	172	static int con_init(struct XenDevice *xendev)
	173	{
	174	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
0f51726a	175	char type, dom, label[32];
5e6b701a	176	int ret = 0;
0f51726a	177	const char *output;
e57dd20b AL	178
	179	/* setup */
	180	dom = xs_get_domain_path(xenstore, con->xendev.dom);
2c1d4d15 SS	181	if (!xendev->dev) {
	182	snprintf(con->console, sizeof(con->console), "%s/console", dom);
	183	} else {
	184	snprintf(con->console, sizeof(con->console), "%s/device/console/%d", dom, xendev->dev);
	185	}
e57dd20b AL	186	free(dom);
	187
	188	type = xenstore_read_str(con->console, "type");
96248fd8	189	if (!type \|\| strcmp(type, "ioemu") != 0) {
e57dd20b	190	xen_be_printf(xendev, 1, "not for me (type=%s)\n", type);
5e6b701a SS	191	ret = -1;
5e6b701a SS	192	goto out;
e57dd20b AL	193	}
e57dd20b AL	194
0f51726a	195	output = xenstore_read_str(con->console, "output");
25a11813 AG	196
25a11813 AG	197	/* no Xen override, use qemu output device */
0f51726a	198	if (output == NULL) {
25a11813 AG	199	con->chr = serial_hds[con->xendev.dev];
	200	} else {
	201	snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
27143a44	202	con->chr = qemu_chr_new(label, output, NULL);
0f51726a	203	}
25a11813	204
0f51726a	205	xenstore_store_pv_console_info(con->xendev.dev, con->chr);
e57dd20b	206
5e6b701a	207	out:
7267c094	208	g_free(type);
5e6b701a	209	return ret;
e57dd20b AL	210	}
e57dd20b AL	211
384087b2	212	static int con_initialise(struct XenDevice *xendev)
e57dd20b AL	213	{
	214	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	215	int limit;
	216
	217	if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
	218	return -1;
	219	if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
	220	return -1;
	221	if (xenstore_read_int(con->console, "limit", &limit) == 0)
	222	con->buffer.max_capacity = limit;
	223
2c1d4d15	224	if (!xendev->dev) {
9ed257d1	225	xen_pfn_t mfn = con->ring_ref;
e0cb42ae IC	226	con->sring = xenforeignmemory_map(xen_fmem, con->xendev.dom,
	227	PROT_READ\|PROT_WRITE,
	228	1, &mfn, NULL);
2c1d4d15	229	} else {
c1345a88	230	con->sring = xengnttab_map_grant_ref(xendev->gnttabdev, con->xendev.dom,
2c1d4d15 SS	231	con->ring_ref,
	232	PROT_READ\|PROT_WRITE);
	233	}
e57dd20b AL	234	if (!con->sring)
	235	return -1;
	236
	237	xen_be_bind_evtchn(&con->xendev);
456d6069 HG	238	if (con->chr) {
	239	if (qemu_chr_fe_claim(con->chr) == 0) {
	240	qemu_chr_add_handlers(con->chr, xencons_can_receive,
	241	xencons_receive, NULL, con);
	242	} else {
	243	xen_be_printf(xendev, 0,
	244	"xen_console_init error chardev %s already used\n",
	245	con->chr->label);
	246	con->chr = NULL;
	247	}
	248	}
e57dd20b AL	249
	250	xen_be_printf(xendev, 1, "ring mfn %d, remote port %d, local port %d, limit %zd\n",
	251	con->ring_ref,
	252	con->xendev.remote_port,
	253	con->xendev.local_port,
	254	con->buffer.max_capacity);
	255	return 0;
	256	}
	257
	258	static void con_disconnect(struct XenDevice *xendev)
	259	{
	260	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	261
456d6069	262	if (con->chr) {
e57dd20b	263	qemu_chr_add_handlers(con->chr, NULL, NULL, NULL, NULL);
456d6069 HG	264	qemu_chr_fe_release(con->chr);
456d6069 HG	265	}
e57dd20b AL	266	xen_be_unbind_evtchn(&con->xendev);
	267
	268	if (con->sring) {
549e9bca	269	if (!xendev->dev) {
e0cb42ae	270	xenforeignmemory_unmap(xen_fmem, con->sring, 1);
2c1d4d15	271	} else {
c1345a88	272	xengnttab_unmap(xendev->gnttabdev, con->sring, 1);
2c1d4d15	273	}
549e9bca	274	con->sring = NULL;
e57dd20b AL	275	}
	276	}
	277
	278	static void con_event(struct XenDevice *xendev)
	279	{
	280	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	281
	282	buffer_append(con);
	283	if (con->buffer.size - con->buffer.consumed)
	284	xencons_send(con);
	285	}
	286
	287	/* -------------------------------------------------------------------- */
	288
	289	struct XenDevOps xen_console_ops = {
	290	.size = sizeof(struct XenConsole),
2c1d4d15	291	.flags = DEVOPS_FLAG_IGNORE_STATE\|DEVOPS_FLAG_NEED_GNTDEV,
e57dd20b	292	.init = con_init,
384087b2	293	.initialise = con_initialise,
e57dd20b AL	294	.event = con_event,
	295	.disconnect = con_disconnect,
	296	};