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

#include "qapi/error.h"
#include "hw/hw.h"
#include "chardev/char-fe.h"
#include "hw/xen/xen_backend.h"
#include "qapi/error.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;
    CharBackend       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_pv_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_pv_send_notify(&con->xendev);
}

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

    size = con->buffer.size - con->buffer.consumed;
    if (qemu_chr_fe_get_driver(&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_pv_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_pv_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_pv_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) {
        if (con->xendev.dev) {
            qemu_chr_fe_init(&con->chr, serial_hds[con->xendev.dev],
                             &error_abort);
        }
    } else {
        snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
        qemu_chr_fe_init(&con->chr,
                         qemu_chr_new(label, output), &error_abort);
    }

    xenstore_store_pv_console_info(con->xendev.dev,
                                   qemu_chr_fe_get_driver(&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);
    qemu_chr_fe_set_handlers(&con->chr, xencons_can_receive,
                             xencons_receive, NULL, NULL, con, NULL, true);

    xen_pv_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);

    qemu_chr_fe_deinit(&con->chr, false);
    xen_pv_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 <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	*/
e57dd20b AL	21
21cbfe5f	22	#include "qemu/osdep.h"
e57dd20b	23	#include <sys/select.h>
e57dd20b	24	#include <termios.h>
e57dd20b	25
5345fdb4	26	#include "qapi/error.h"
83c9f4ca	27	#include "hw/hw.h"
4d43a603	28	#include "chardev/char-fe.h"
0d09e41a	29	#include "hw/xen/xen_backend.h"
32a6ebec	30	#include "qapi/error.h"
e57dd20b	31
b41f6719 AP	32	#include <xen/io/console.h>
b41f6719 AP	33
e57dd20b AL	34	struct buffer {
	35	uint8_t *data;
	36	size_t consumed;
	37	size_t size;
	38	size_t capacity;
	39	size_t max_capacity;
	40	};
	41
	42	struct XenConsole {
	43	struct XenDevice xendev; /* must be first */
	44	struct buffer buffer;
	45	char console[XEN_BUFSIZE];
	46	int ring_ref;
	47	void *sring;
32a6ebec	48	CharBackend chr;
e57dd20b AL	49	int backlog;
	50	};
	51
	52	static void buffer_append(struct XenConsole *con)
	53	{
	54	struct buffer *buffer = &con->buffer;
	55	XENCONS_RING_IDX cons, prod, size;
	56	struct xencons_interface *intf = con->sring;
	57
	58	cons = intf->out_cons;
	59	prod = intf->out_prod;
	60	xen_mb();
	61
	62	size = prod - cons;
	63	if ((size == 0) \|\| (size > sizeof(intf->out)))
	64	return;
	65
	66	if ((buffer->capacity - buffer->size) < size) {
	67	buffer->capacity += (size + 1024);
7267c094	68	buffer->data = g_realloc(buffer->data, buffer->capacity);
e57dd20b AL	69	}
	70
	71	while (cons != prod)
	72	buffer->data[buffer->size++] = intf->out[
	73	MASK_XENCONS_IDX(cons++, intf->out)];
	74
	75	xen_mb();
	76	intf->out_cons = cons;
ba18fa2a	77	xen_pv_send_notify(&con->xendev);
e57dd20b AL	78
	79	if (buffer->max_capacity &&
	80	buffer->size > buffer->max_capacity) {
	81	/* Discard the middle of the data. */
	82
	83	size_t over = buffer->size - buffer->max_capacity;
	84	uint8_t *maxpos = buffer->data + buffer->max_capacity;
	85
	86	memmove(maxpos - over, maxpos, over);
7267c094	87	buffer->data = g_realloc(buffer->data, buffer->max_capacity);
e57dd20b AL	88	buffer->size = buffer->capacity = buffer->max_capacity;
	89
	90	if (buffer->consumed > buffer->max_capacity - over)
	91	buffer->consumed = buffer->max_capacity - over;
	92	}
	93	}
	94
	95	static void buffer_advance(struct buffer *buffer, size_t len)
	96	{
	97	buffer->consumed += len;
	98	if (buffer->consumed == buffer->size) {
	99	buffer->consumed = 0;
	100	buffer->size = 0;
	101	}
	102	}
	103
	104	static int ring_free_bytes(struct XenConsole *con)
	105	{
	106	struct xencons_interface *intf = con->sring;
	107	XENCONS_RING_IDX cons, prod, space;
	108
	109	cons = intf->in_cons;
	110	prod = intf->in_prod;
	111	xen_mb();
	112
	113	space = prod - cons;
	114	if (space > sizeof(intf->in))
	115	return 0; /* ring is screwed: ignore it */
	116
	117	return (sizeof(intf->in) - space);
	118	}
	119
	120	static int xencons_can_receive(void *opaque)
	121	{
	122	struct XenConsole *con = opaque;
	123	return ring_free_bytes(con);
	124	}
	125
	126	static void xencons_receive(void opaque, const uint8_t buf, int len)
	127	{
	128	struct XenConsole *con = opaque;
	129	struct xencons_interface *intf = con->sring;
	130	XENCONS_RING_IDX prod;
	131	int i, max;
	132
	133	max = ring_free_bytes(con);
	134	/* The can_receive() func limits this, but check again anyway */
	135	if (max < len)
	136	len = max;
	137
	138	prod = intf->in_prod;
	139	for (i = 0; i < len; i++) {
	140	intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
	141	buf[i];
	142	}
	143	xen_wmb();
	144	intf->in_prod = prod;
ba18fa2a	145	xen_pv_send_notify(&con->xendev);
e57dd20b AL	146	}
	147
	148	static void xencons_send(struct XenConsole *con)
	149	{
	150	ssize_t len, size;
	151
	152	size = con->buffer.size - con->buffer.consumed;
5345fdb4 MAL	153	if (qemu_chr_fe_get_driver(&con->chr)) {
5345fdb4 MAL	154	len = qemu_chr_fe_write(&con->chr,
32a6ebec MAL	155	con->buffer.data + con->buffer.consumed,
	156	size);
	157	} else {
e57dd20b	158	len = size;
32a6ebec	159	}
e57dd20b	160	if (len < 1) {
c22e91b1 EC	161	if (!con->backlog) {
c22e91b1 EC	162	con->backlog = 1;
96c77dba	163	xen_pv_printf(&con->xendev, 1,
c22e91b1 EC	164	"backlog piling up, nobody listening?\n");
c22e91b1 EC	165	}
e57dd20b	166	} else {
c22e91b1 EC	167	buffer_advance(&con->buffer, len);
	168	if (con->backlog && len == size) {
	169	con->backlog = 0;
96c77dba	170	xen_pv_printf(&con->xendev, 1, "backlog is gone\n");
c22e91b1	171	}
e57dd20b AL	172	}
	173	}
	174
	175	/* -------------------------------------------------------------------- */
	176
	177	static int con_init(struct XenDevice *xendev)
	178	{
	179	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
0f51726a	180	char type, dom, label[32];
5e6b701a	181	int ret = 0;
0f51726a	182	const char *output;
e57dd20b AL	183
	184	/* setup */
	185	dom = xs_get_domain_path(xenstore, con->xendev.dom);
2c1d4d15 SS	186	if (!xendev->dev) {
	187	snprintf(con->console, sizeof(con->console), "%s/console", dom);
	188	} else {
	189	snprintf(con->console, sizeof(con->console), "%s/device/console/%d", dom, xendev->dev);
	190	}
e57dd20b AL	191	free(dom);
	192
	193	type = xenstore_read_str(con->console, "type");
96248fd8	194	if (!type \|\| strcmp(type, "ioemu") != 0) {
96c77dba	195	xen_pv_printf(xendev, 1, "not for me (type=%s)\n", type);
5e6b701a SS	196	ret = -1;
5e6b701a SS	197	goto out;
e57dd20b AL	198	}
e57dd20b AL	199
0f51726a	200	output = xenstore_read_str(con->console, "output");
25a11813 AG	201
25a11813 AG	202	/* no Xen override, use qemu output device */
0f51726a	203	if (output == NULL) {
32a6ebec MAL	204	if (con->xendev.dev) {
	205	qemu_chr_fe_init(&con->chr, serial_hds[con->xendev.dev],
	206	&error_abort);
	207	}
25a11813 AG	208	} else {
25a11813 AG	209	snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
32a6ebec MAL	210	qemu_chr_fe_init(&con->chr,
32a6ebec MAL	211	qemu_chr_new(label, output), &error_abort);
0f51726a	212	}
25a11813	213
5345fdb4 MAL	214	xenstore_store_pv_console_info(con->xendev.dev,
5345fdb4 MAL	215	qemu_chr_fe_get_driver(&con->chr));
e57dd20b	216
5e6b701a	217	out:
7267c094	218	g_free(type);
5e6b701a	219	return ret;
e57dd20b AL	220	}
e57dd20b AL	221
384087b2	222	static int con_initialise(struct XenDevice *xendev)
e57dd20b AL	223	{
	224	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	225	int limit;
	226
	227	if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
	228	return -1;
	229	if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
	230	return -1;
	231	if (xenstore_read_int(con->console, "limit", &limit) == 0)
	232	con->buffer.max_capacity = limit;
	233
2c1d4d15	234	if (!xendev->dev) {
9ed257d1	235	xen_pfn_t mfn = con->ring_ref;
e0cb42ae IC	236	con->sring = xenforeignmemory_map(xen_fmem, con->xendev.dom,
	237	PROT_READ\|PROT_WRITE,
	238	1, &mfn, NULL);
2c1d4d15	239	} else {
c1345a88	240	con->sring = xengnttab_map_grant_ref(xendev->gnttabdev, con->xendev.dom,
2c1d4d15 SS	241	con->ring_ref,
	242	PROT_READ\|PROT_WRITE);
	243	}
e57dd20b AL	244	if (!con->sring)
	245	return -1;
	246
	247	xen_be_bind_evtchn(&con->xendev);
fa394ed6	248	qemu_chr_fe_set_handlers(&con->chr, xencons_can_receive,
81517ba3	249	xencons_receive, NULL, NULL, con, NULL, true);
e57dd20b	250
96c77dba	251	xen_pv_printf(xendev, 1,
b9730c5b	252	"ring mfn %d, remote port %d, local port %d, limit %zd\n",
e57dd20b AL	253	con->ring_ref,
	254	con->xendev.remote_port,
	255	con->xendev.local_port,
	256	con->buffer.max_capacity);
	257	return 0;
	258	}
	259
	260	static void con_disconnect(struct XenDevice *xendev)
	261	{
	262	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	263
1ce2610c	264	qemu_chr_fe_deinit(&con->chr, false);
65807f4b	265	xen_pv_unbind_evtchn(&con->xendev);
e57dd20b AL	266
e57dd20b AL	267	if (con->sring) {
549e9bca	268	if (!xendev->dev) {
e0cb42ae	269	xenforeignmemory_unmap(xen_fmem, con->sring, 1);
2c1d4d15	270	} else {
c1345a88	271	xengnttab_unmap(xendev->gnttabdev, con->sring, 1);
2c1d4d15	272	}
549e9bca	273	con->sring = NULL;
e57dd20b AL	274	}
	275	}
	276
	277	static void con_event(struct XenDevice *xendev)
	278	{
	279	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	280
	281	buffer_append(con);
	282	if (con->buffer.size - con->buffer.consumed)
	283	xencons_send(con);
	284	}
	285
	286	/* -------------------------------------------------------------------- */
	287
	288	struct XenDevOps xen_console_ops = {
	289	.size = sizeof(struct XenConsole),
2c1d4d15	290	.flags = DEVOPS_FLAG_IGNORE_STATE\|DEVOPS_FLAG_NEED_GNTDEV,
e57dd20b	291	.init = con_init,
384087b2	292	.initialise = con_initialise,
e57dd20b AL	293	.event = con_event,
	294	.disconnect = con_disconnect,
	295	};