[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 "qapi/error.h"
#include "hw/hw.h"
#include "chardev/char-fe.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;
    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_backend_connected(&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 <[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
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"
e57dd20b	30
b41f6719 AP	31	#include <xen/io/console.h>
b41f6719 AP	32
e57dd20b AL	33	struct buffer {
	34	uint8_t *data;
	35	size_t consumed;
	36	size_t size;
	37	size_t capacity;
	38	size_t max_capacity;
	39	};
	40
	41	struct XenConsole {
	42	struct XenDevice xendev; /* must be first */
	43	struct buffer buffer;
	44	char console[XEN_BUFSIZE];
	45	int ring_ref;
	46	void *sring;
32a6ebec	47	CharBackend chr;
e57dd20b AL	48	int backlog;
	49	};
	50
	51	static void buffer_append(struct XenConsole *con)
	52	{
	53	struct buffer *buffer = &con->buffer;
	54	XENCONS_RING_IDX cons, prod, size;
	55	struct xencons_interface *intf = con->sring;
	56
	57	cons = intf->out_cons;
	58	prod = intf->out_prod;
	59	xen_mb();
	60
	61	size = prod - cons;
	62	if ((size == 0) \|\| (size > sizeof(intf->out)))
	63	return;
	64
	65	if ((buffer->capacity - buffer->size) < size) {
	66	buffer->capacity += (size + 1024);
7267c094	67	buffer->data = g_realloc(buffer->data, buffer->capacity);
e57dd20b AL	68	}
	69
	70	while (cons != prod)
	71	buffer->data[buffer->size++] = intf->out[
	72	MASK_XENCONS_IDX(cons++, intf->out)];
	73
	74	xen_mb();
	75	intf->out_cons = cons;
ba18fa2a	76	xen_pv_send_notify(&con->xendev);
e57dd20b AL	77
	78	if (buffer->max_capacity &&
	79	buffer->size > buffer->max_capacity) {
	80	/* Discard the middle of the data. */
	81
	82	size_t over = buffer->size - buffer->max_capacity;
	83	uint8_t *maxpos = buffer->data + buffer->max_capacity;
	84
	85	memmove(maxpos - over, maxpos, over);
7267c094	86	buffer->data = g_realloc(buffer->data, buffer->max_capacity);
e57dd20b AL	87	buffer->size = buffer->capacity = buffer->max_capacity;
	88
	89	if (buffer->consumed > buffer->max_capacity - over)
	90	buffer->consumed = buffer->max_capacity - over;
	91	}
	92	}
	93
	94	static void buffer_advance(struct buffer *buffer, size_t len)
	95	{
	96	buffer->consumed += len;
	97	if (buffer->consumed == buffer->size) {
	98	buffer->consumed = 0;
	99	buffer->size = 0;
	100	}
	101	}
	102
	103	static int ring_free_bytes(struct XenConsole *con)
	104	{
	105	struct xencons_interface *intf = con->sring;
	106	XENCONS_RING_IDX cons, prod, space;
	107
	108	cons = intf->in_cons;
	109	prod = intf->in_prod;
	110	xen_mb();
	111
	112	space = prod - cons;
	113	if (space > sizeof(intf->in))
	114	return 0; /* ring is screwed: ignore it */
	115
	116	return (sizeof(intf->in) - space);
	117	}
	118
	119	static int xencons_can_receive(void *opaque)
	120	{
	121	struct XenConsole *con = opaque;
	122	return ring_free_bytes(con);
	123	}
	124
	125	static void xencons_receive(void opaque, const uint8_t buf, int len)
	126	{
	127	struct XenConsole *con = opaque;
	128	struct xencons_interface *intf = con->sring;
	129	XENCONS_RING_IDX prod;
	130	int i, max;
	131
	132	max = ring_free_bytes(con);
	133	/* The can_receive() func limits this, but check again anyway */
	134	if (max < len)
	135	len = max;
	136
	137	prod = intf->in_prod;
	138	for (i = 0; i < len; i++) {
	139	intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
	140	buf[i];
	141	}
	142	xen_wmb();
	143	intf->in_prod = prod;
ba18fa2a	144	xen_pv_send_notify(&con->xendev);
e57dd20b AL	145	}
	146
	147	static void xencons_send(struct XenConsole *con)
	148	{
	149	ssize_t len, size;
	150
	151	size = con->buffer.size - con->buffer.consumed;
30650701	152	if (qemu_chr_fe_backend_connected(&con->chr)) {
5345fdb4	153	len = qemu_chr_fe_write(&con->chr,
32a6ebec MAL	154	con->buffer.data + con->buffer.consumed,
	155	size);
	156	} else {
e57dd20b	157	len = size;
32a6ebec	158	}
e57dd20b	159	if (len < 1) {
c22e91b1 EC	160	if (!con->backlog) {
c22e91b1 EC	161	con->backlog = 1;
96c77dba	162	xen_pv_printf(&con->xendev, 1,
c22e91b1 EC	163	"backlog piling up, nobody listening?\n");
c22e91b1 EC	164	}
e57dd20b	165	} else {
c22e91b1 EC	166	buffer_advance(&con->buffer, len);
	167	if (con->backlog && len == size) {
	168	con->backlog = 0;
96c77dba	169	xen_pv_printf(&con->xendev, 1, "backlog is gone\n");
c22e91b1	170	}
e57dd20b AL	171	}
	172	}
	173
	174	/* -------------------------------------------------------------------- */
	175
	176	static int con_init(struct XenDevice *xendev)
	177	{
	178	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
0f51726a	179	char type, dom, label[32];
5e6b701a	180	int ret = 0;
0f51726a	181	const char *output;
e57dd20b AL	182
	183	/* setup */
	184	dom = xs_get_domain_path(xenstore, con->xendev.dom);
2c1d4d15 SS	185	if (!xendev->dev) {
	186	snprintf(con->console, sizeof(con->console), "%s/console", dom);
	187	} else {
	188	snprintf(con->console, sizeof(con->console), "%s/device/console/%d", dom, xendev->dev);
	189	}
e57dd20b AL	190	free(dom);
	191
	192	type = xenstore_read_str(con->console, "type");
96248fd8	193	if (!type \|\| strcmp(type, "ioemu") != 0) {
96c77dba	194	xen_pv_printf(xendev, 1, "not for me (type=%s)\n", type);
5e6b701a SS	195	ret = -1;
5e6b701a SS	196	goto out;
e57dd20b AL	197	}
e57dd20b AL	198
0f51726a	199	output = xenstore_read_str(con->console, "output");
25a11813 AG	200
25a11813 AG	201	/* no Xen override, use qemu output device */
0f51726a	202	if (output == NULL) {
32a6ebec MAL	203	if (con->xendev.dev) {
	204	qemu_chr_fe_init(&con->chr, serial_hds[con->xendev.dev],
	205	&error_abort);
	206	}
25a11813 AG	207	} else {
25a11813 AG	208	snprintf(label, sizeof(label), "xencons%d", con->xendev.dev);
32a6ebec MAL	209	qemu_chr_fe_init(&con->chr,
32a6ebec MAL	210	qemu_chr_new(label, output), &error_abort);
0f51726a	211	}
25a11813	212
5345fdb4 MAL	213	xenstore_store_pv_console_info(con->xendev.dev,
5345fdb4 MAL	214	qemu_chr_fe_get_driver(&con->chr));
e57dd20b	215
5e6b701a	216	out:
7267c094	217	g_free(type);
5e6b701a	218	return ret;
e57dd20b AL	219	}
e57dd20b AL	220
384087b2	221	static int con_initialise(struct XenDevice *xendev)
e57dd20b AL	222	{
	223	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	224	int limit;
	225
	226	if (xenstore_read_int(con->console, "ring-ref", &con->ring_ref) == -1)
	227	return -1;
	228	if (xenstore_read_int(con->console, "port", &con->xendev.remote_port) == -1)
	229	return -1;
	230	if (xenstore_read_int(con->console, "limit", &limit) == 0)
	231	con->buffer.max_capacity = limit;
	232
2c1d4d15	233	if (!xendev->dev) {
9ed257d1	234	xen_pfn_t mfn = con->ring_ref;
e0cb42ae IC	235	con->sring = xenforeignmemory_map(xen_fmem, con->xendev.dom,
	236	PROT_READ\|PROT_WRITE,
	237	1, &mfn, NULL);
2c1d4d15	238	} else {
c1345a88	239	con->sring = xengnttab_map_grant_ref(xendev->gnttabdev, con->xendev.dom,
2c1d4d15 SS	240	con->ring_ref,
	241	PROT_READ\|PROT_WRITE);
	242	}
e57dd20b AL	243	if (!con->sring)
	244	return -1;
	245
	246	xen_be_bind_evtchn(&con->xendev);
fa394ed6	247	qemu_chr_fe_set_handlers(&con->chr, xencons_can_receive,
81517ba3	248	xencons_receive, NULL, NULL, con, NULL, true);
e57dd20b	249
96c77dba	250	xen_pv_printf(xendev, 1,
b9730c5b	251	"ring mfn %d, remote port %d, local port %d, limit %zd\n",
e57dd20b AL	252	con->ring_ref,
	253	con->xendev.remote_port,
	254	con->xendev.local_port,
	255	con->buffer.max_capacity);
	256	return 0;
	257	}
	258
	259	static void con_disconnect(struct XenDevice *xendev)
	260	{
	261	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	262
1ce2610c	263	qemu_chr_fe_deinit(&con->chr, false);
65807f4b	264	xen_pv_unbind_evtchn(&con->xendev);
e57dd20b AL	265
e57dd20b AL	266	if (con->sring) {
549e9bca	267	if (!xendev->dev) {
e0cb42ae	268	xenforeignmemory_unmap(xen_fmem, con->sring, 1);
2c1d4d15	269	} else {
c1345a88	270	xengnttab_unmap(xendev->gnttabdev, con->sring, 1);
2c1d4d15	271	}
549e9bca	272	con->sring = NULL;
e57dd20b AL	273	}
	274	}
	275
	276	static void con_event(struct XenDevice *xendev)
	277	{
	278	struct XenConsole *con = container_of(xendev, struct XenConsole, xendev);
	279
	280	buffer_append(con);
	281	if (con->buffer.size - con->buffer.consumed)
	282	xencons_send(con);
	283	}
	284
	285	/* -------------------------------------------------------------------- */
	286
	287	struct XenDevOps xen_console_ops = {
	288	.size = sizeof(struct XenConsole),
2c1d4d15	289	.flags = DEVOPS_FLAG_IGNORE_STATE\|DEVOPS_FLAG_NEED_GNTDEV,
e57dd20b	290	.init = con_init,
384087b2	291	.initialise = con_initialise,
e57dd20b AL	292	.event = con_event,
	293	.disconnect = con_disconnect,
	294	};