hw/char/sclpconsole-lm.c - qemu - Git at Google

 /*
  * SCLP event types
  *    Operations Command - Line Mode input
  *    Message            - Line Mode output
  *
  * Copyright IBM, Corp. 2013
  *
  * Authors:
  *  Heinz Graalfs <graalfs@linux.vnet.ibm.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
  * option) any later version.  See the COPYING file in the top-level directory.
  *
  */

 #include "hw/qdev.h"
 #include "qemu/thread.h"
 #include "qemu/error-report.h"
 #include "sysemu/char.h"

 #include "hw/s390x/sclp.h"
 #include "hw/s390x/event-facility.h"
 #include "hw/s390x/ebcdic.h"

 #define SIZE_BUFFER 4096
 #define NEWLINE     "\n"

 typedef struct OprtnsCommand {
     EventBufferHeader header;
     MDMSU message_unit;
     char data[0];
 } QEMU_PACKED OprtnsCommand;

 /* max size for line-mode data in 4K SCCB page */
 #define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))

 typedef struct SCLPConsoleLM {
     SCLPEvent event;
     CharDriverState *chr;
     bool echo;                  /* immediate echo of input if true        */
     uint32_t write_errors;      /* errors writing to char layer           */
     uint32_t length;            /* length of byte stream in buffer        */
     uint8_t buf[SIZE_CONSOLE_BUFFER];
 } SCLPConsoleLM;

 /*
 *  Character layer call-back functions
  *
  * Allow 1 character at a time
  *
  * Accumulate bytes from character layer in console buffer,
  * event_pending is set when a newline character is encountered
  *
  * The maximum command line length is limited by the maximum
  * space available in an SCCB. Line mode console input is sent
  * truncated to the guest in case it doesn't fit into the SCCB.
  */

 static int chr_can_read(void *opaque)
 {
     SCLPConsoleLM *scon = opaque;

     if (scon->event.event_pending) {
         return 0;
     }
     return 1;
 }

 static void chr_read(void *opaque, const uint8_t *buf, int size)
 {
     SCLPConsoleLM *scon = opaque;

     assert(size == 1);

     if (*buf == '\r' || *buf == '\n') {
         scon->event.event_pending = true;
         sclp_service_interrupt(0);
         return;
     }
     if (scon->length == SIZE_CONSOLE_BUFFER) {
         /* Eat the character, but still process CR and LF.  */
         return;
     }
     scon->buf[scon->length] = *buf;
     scon->length += 1;
     if (scon->echo) {
         qemu_chr_fe_write(scon->chr, buf, size);
     }
 }

 /* functions to be called by event facility */

 static bool can_handle_event(uint8_t type)
 {
     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
 }

 static unsigned int send_mask(void)
 {
     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
 }

 static unsigned int receive_mask(void)
 {
     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
 }

 /*
  * Triggered by SCLP's read_event_data
  * - convert ASCII byte stream to EBCDIC and
  * - copy converted data into provided (SCLP) buffer
  */
 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
                             int avail)
 {
     int len;

     SCLPConsoleLM *cons = DO_UPCAST(SCLPConsoleLM, event, event);

     len = cons->length;
     /* data need to fit into provided SCLP buffer */
     if (len > avail) {
         return 1;
     }

     ebcdic_put(buf, (char *)&cons->buf, len);
     *size = len;
     cons->length = 0;
     /* data provided and no more data pending */
     event->event_pending = false;
     qemu_notify_event();
     return 0;
 }

 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
                            int *slen)
 {
     int avail, rc;
     size_t src_len;
     uint8_t *to;
     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;

     if (!event->event_pending) {
         /* no data pending */
         return 0;
     }

     to = (uint8_t *)&oc->data;
     avail = *slen - sizeof(OprtnsCommand);
     rc = get_console_data(event, to, &src_len, avail);
     if (rc) {
         /* data didn't fit, try next SCCB */
         return 1;
     }

     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));

     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
     oc->message_unit.cpmsu.length =
         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));

     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
     oc->message_unit.text_command.length =
         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));

     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
     oc->message_unit.self_def_text_message.length =
         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));

     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
     oc->message_unit.text_message.length =
         cpu_to_be16(sizeof(GdsSubvector) + src_len);

     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
     *slen = avail - src_len;

     return 1;
 }

 /*
  * Triggered by SCLP's write_event_data
  *  - write console data to character layer
  *  returns < 0 if an error occurred
  */
 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
 {
     int ret = 0;
     const uint8_t *buf_offset;

     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);

     if (!scon->chr) {
         /* If there's no backend, we can just say we consumed all data. */
         return len;
     }

     buf_offset = buf;
     while (len > 0) {
         ret = qemu_chr_fe_write(scon->chr, buf, len);
         if (ret == 0) {
             /* a pty doesn't seem to be connected - no error */
             len = 0;
         } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
             len -= ret;
             buf_offset += ret;
         } else {
             len = 0;
         }
     }

     return ret;
 }

 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
 {
     int rc;
     int len;
     uint8_t buffer[SIZE_BUFFER];

     len = be16_to_cpu(mdbo->length);
     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
             + sizeof(mdbo->mto.line_type_flags)
             + sizeof(mdbo->mto.alarm_control)
             + sizeof(mdbo->mto._reserved);

     assert(len <= SIZE_BUFFER);

     /* convert EBCDIC SCLP contents to ASCII console message */
     ascii_put(buffer, mdbo->mto.message, len);
     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
     if (rc < 0) {
         return rc;
     }
     return write_console_data(event, buffer, len);
 }

 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
 {
     int len;
     int written;
     int errors = 0;
     MDBO *mdbo;
     SclpMsg *data = (SclpMsg *) ebh;
     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);

     len = be16_to_cpu(data->mdb.header.length);
     if (len < sizeof(data->mdb.header)) {
         return SCLP_RC_INCONSISTENT_LENGTHS;
     }
     len -= sizeof(data->mdb.header);

     /* first check message buffers */
     mdbo = data->mdb.mdbo;
     while (len > 0) {
         if (be16_to_cpu(mdbo->length) > len
                 || be16_to_cpu(mdbo->length) == 0) {
             return SCLP_RC_INCONSISTENT_LENGTHS;
         }
         len -= be16_to_cpu(mdbo->length);
         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
     }

     /* then execute */
     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
     mdbo = data->mdb.mdbo;
     while (len > 0) {
         switch (be16_to_cpu(mdbo->type)) {
         case MESSAGE_TEXT:
             /* message text object */
             written = process_mdb(event, mdbo);
             if (written < 0) {
                 /* character layer error */
                 errors++;
             }
             break;
         default: /* ignore */
             break;
         }
         len -= be16_to_cpu(mdbo->length);
         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
     }
     if (errors) {
         scon->write_errors += errors;
     }
     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;

     return SCLP_RC_NORMAL_COMPLETION;
 }

 /* functions for live migration */

 static const VMStateDescription vmstate_sclplmconsole = {
     .name = "sclplmconsole",
     .version_id = 0,
     .minimum_version_id = 0,
     .fields = (VMStateField[]) {
         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
         VMSTATE_UINT32(length, SCLPConsoleLM),
         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
         VMSTATE_END_OF_LIST()
      }
 };

 /* qemu object creation and initialization functions */

 /* tell character layer our call-back functions */

 static int console_init(SCLPEvent *event)
 {
     static bool console_available;

     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);

     if (console_available) {
         error_report("Multiple line-mode operator consoles are not supported");
         return -1;
     }
     console_available = true;

     if (scon->chr) {
         qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
     }

     return 0;
 }

 static int console_exit(SCLPEvent *event)
 {
     return 0;
 }

 static void console_reset(DeviceState *dev)
 {
    SCLPEvent *event = SCLP_EVENT(dev);
    SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);

    event->event_pending = false;
    scon->length = 0;
    scon->write_errors = 0;
 }

 static Property console_properties[] = {
     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
     DEFINE_PROP_END_OF_LIST(),
 };

 static void console_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);

     dc->props = console_properties;
     dc->reset = console_reset;
     dc->vmsd = &vmstate_sclplmconsole;
     ec->init = console_init;
     ec->exit = console_exit;
     ec->get_send_mask = send_mask;
     ec->get_receive_mask = receive_mask;
     ec->can_handle_event = can_handle_event;
     ec->read_event_data = read_event_data;
     ec->write_event_data = write_event_data;
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 }

 static const TypeInfo sclp_console_info = {
     .name          = "sclplmconsole",
     .parent        = TYPE_SCLP_EVENT,
     .instance_size = sizeof(SCLPConsoleLM),
     .class_init    = console_class_init,
     .class_size    = sizeof(SCLPEventClass),
 };

 static void register_types(void)
 {
     type_register_static(&sclp_console_info);
 }

 type_init(register_types)
	/*
	* SCLP event types
	* Operations Command - Line Mode input
	* Message - Line Mode output
	*
	* Copyright IBM, Corp. 2013
	*
	* Authors:
	* Heinz Graalfs <graalfs@linux.vnet.ibm.com>
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or (at your
	* option) any later version. See the COPYING file in the top-level directory.
	*
	*/

	#include "hw/qdev.h"
	#include "qemu/thread.h"
	#include "qemu/error-report.h"
	#include "sysemu/char.h"

	#include "hw/s390x/sclp.h"
	#include "hw/s390x/event-facility.h"
	#include "hw/s390x/ebcdic.h"

	#define SIZE_BUFFER 4096
	#define NEWLINE "\n"

	typedef struct OprtnsCommand {
	EventBufferHeader header;
	MDMSU message_unit;
	char data[0];
	} QEMU_PACKED OprtnsCommand;

	/* max size for line-mode data in 4K SCCB page */
	#define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))

	typedef struct SCLPConsoleLM {
	SCLPEvent event;
	CharDriverState *chr;
	bool echo; /* immediate echo of input if true */
	uint32_t write_errors; /* errors writing to char layer */
	uint32_t length; /* length of byte stream in buffer */
	uint8_t buf[SIZE_CONSOLE_BUFFER];
	} SCLPConsoleLM;

	/*
	* Character layer call-back functions
	*
	* Allow 1 character at a time
	*
	* Accumulate bytes from character layer in console buffer,
	* event_pending is set when a newline character is encountered
	*
	* The maximum command line length is limited by the maximum
	* space available in an SCCB. Line mode console input is sent
	* truncated to the guest in case it doesn't fit into the SCCB.
	*/

	static int chr_can_read(void *opaque)
	{
	SCLPConsoleLM *scon = opaque;

	if (scon->event.event_pending) {
	return 0;
	}
	return 1;
	}

	static void chr_read(void opaque, const uint8_t buf, int size)
	{
	SCLPConsoleLM *scon = opaque;

	assert(size == 1);

	if (buf == '\r' \|\| buf == '\n') {
	scon->event.event_pending = true;
	sclp_service_interrupt(0);
	return;
	}
	if (scon->length == SIZE_CONSOLE_BUFFER) {
	/* Eat the character, but still process CR and LF. */
	return;
	}
	scon->buf[scon->length] = *buf;
	scon->length += 1;
	if (scon->echo) {
	qemu_chr_fe_write(scon->chr, buf, size);
	}
	}

	/* functions to be called by event facility */

	static bool can_handle_event(uint8_t type)
	{
	return type == SCLP_EVENT_MESSAGE \|\| type == SCLP_EVENT_PMSGCMD;
	}

	static unsigned int send_mask(void)
	{
	return SCLP_EVENT_MASK_OP_CMD \| SCLP_EVENT_MASK_PMSGCMD;
	}

	static unsigned int receive_mask(void)
	{
	return SCLP_EVENT_MASK_MSG \| SCLP_EVENT_MASK_PMSGCMD;
	}

	/*
	* Triggered by SCLP's read_event_data
	* - convert ASCII byte stream to EBCDIC and
	* - copy converted data into provided (SCLP) buffer
	*/
	static int get_console_data(SCLPEvent event, uint8_t buf, size_t *size,
	int avail)
	{
	int len;

	SCLPConsoleLM *cons = DO_UPCAST(SCLPConsoleLM, event, event);

	len = cons->length;
	/* data need to fit into provided SCLP buffer */
	if (len > avail) {
	return 1;
	}

	ebcdic_put(buf, (char *)&cons->buf, len);
	*size = len;
	cons->length = 0;
	/* data provided and no more data pending */
	event->event_pending = false;
	qemu_notify_event();
	return 0;
	}

	static int read_event_data(SCLPEvent event, EventBufferHeader evt_buf_hdr,
	int *slen)
	{
	int avail, rc;
	size_t src_len;
	uint8_t *to;
	OprtnsCommand oc = (OprtnsCommand ) evt_buf_hdr;

	if (!event->event_pending) {
	/* no data pending */
	return 0;
	}

	to = (uint8_t *)&oc->data;
	avail = *slen - sizeof(OprtnsCommand);
	rc = get_console_data(event, to, &src_len, avail);
	if (rc) {
	/* data didn't fit, try next SCCB */
	return 1;
	}

	oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
	oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));

	oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
	oc->message_unit.cpmsu.length =
	cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));

	oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
	oc->message_unit.text_command.length =
	cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));

	oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
	oc->message_unit.self_def_text_message.length =
	cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));

	oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
	oc->message_unit.text_message.length =
	cpu_to_be16(sizeof(GdsSubvector) + src_len);

	oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
	oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
	*slen = avail - src_len;

	return 1;
	}

	/*
	* Triggered by SCLP's write_event_data
	* - write console data to character layer
	* returns < 0 if an error occurred
	*/
	static int write_console_data(SCLPEvent event, const uint8_t buf, int len)
	{
	int ret = 0;
	const uint8_t *buf_offset;

	SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);

	if (!scon->chr) {
	/* If there's no backend, we can just say we consumed all data. */
	return len;
	}

	buf_offset = buf;
	while (len > 0) {
	ret = qemu_chr_fe_write(scon->chr, buf, len);
	if (ret == 0) {
	/* a pty doesn't seem to be connected - no error */
	len = 0;
	} else if (ret == -EAGAIN \|\| (ret > 0 && ret < len)) {
	len -= ret;
	buf_offset += ret;
	} else {
	len = 0;
	}
	}

	return ret;
	}

	static int process_mdb(SCLPEvent event, MDBO mdbo)
	{
	int rc;
	int len;
	uint8_t buffer[SIZE_BUFFER];

	len = be16_to_cpu(mdbo->length);
	len -= sizeof(mdbo->length) + sizeof(mdbo->type)
	+ sizeof(mdbo->mto.line_type_flags)
	+ sizeof(mdbo->mto.alarm_control)
	+ sizeof(mdbo->mto._reserved);

	assert(len <= SIZE_BUFFER);

	/* convert EBCDIC SCLP contents to ASCII console message */
	ascii_put(buffer, mdbo->mto.message, len);
	rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
	if (rc < 0) {
	return rc;
	}
	return write_console_data(event, buffer, len);
	}

	static int write_event_data(SCLPEvent event, EventBufferHeader ebh)
	{
	int len;
	int written;
	int errors = 0;
	MDBO *mdbo;
	SclpMsg data = (SclpMsg ) ebh;
	SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);

	len = be16_to_cpu(data->mdb.header.length);
	if (len < sizeof(data->mdb.header)) {
	return SCLP_RC_INCONSISTENT_LENGTHS;
	}
	len -= sizeof(data->mdb.header);

	/* first check message buffers */
	mdbo = data->mdb.mdbo;
	while (len > 0) {
	if (be16_to_cpu(mdbo->length) > len
	\|\| be16_to_cpu(mdbo->length) == 0) {
	return SCLP_RC_INCONSISTENT_LENGTHS;
	}
	len -= be16_to_cpu(mdbo->length);
	mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
	}

	/* then execute */
	len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
	mdbo = data->mdb.mdbo;
	while (len > 0) {
	switch (be16_to_cpu(mdbo->type)) {
	case MESSAGE_TEXT:
	/* message text object */
	written = process_mdb(event, mdbo);
	if (written < 0) {
	/* character layer error */
	errors++;
	}
	break;
	default: /* ignore */
	break;
	}
	len -= be16_to_cpu(mdbo->length);
	mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
	}
	if (errors) {
	scon->write_errors += errors;
	}
	data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;

	return SCLP_RC_NORMAL_COMPLETION;
	}

	/* functions for live migration */

	static const VMStateDescription vmstate_sclplmconsole = {
	.name = "sclplmconsole",
	.version_id = 0,
	.minimum_version_id = 0,
	.fields = (VMStateField[]) {
	VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
	VMSTATE_UINT32(write_errors, SCLPConsoleLM),
	VMSTATE_UINT32(length, SCLPConsoleLM),
	VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
	VMSTATE_END_OF_LIST()
	}
	};

	/* qemu object creation and initialization functions */

	/* tell character layer our call-back functions */

	static int console_init(SCLPEvent *event)
	{
	static bool console_available;

	SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);

	if (console_available) {
	error_report("Multiple line-mode operator consoles are not supported");
	return -1;
	}
	console_available = true;

	if (scon->chr) {
	qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
	}

	return 0;
	}

	static int console_exit(SCLPEvent *event)
	{
	return 0;
	}

	static void console_reset(DeviceState *dev)
	{
	SCLPEvent *event = SCLP_EVENT(dev);
	SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);

	event->event_pending = false;
	scon->length = 0;
	scon->write_errors = 0;
	}

	static Property console_properties[] = {
	DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
	DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
	DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
	DEFINE_PROP_END_OF_LIST(),
	};

	static void console_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);

	dc->props = console_properties;
	dc->reset = console_reset;
	dc->vmsd = &vmstate_sclplmconsole;
	ec->init = console_init;
	ec->exit = console_exit;
	ec->get_send_mask = send_mask;
	ec->get_receive_mask = receive_mask;
	ec->can_handle_event = can_handle_event;
	ec->read_event_data = read_event_data;
	ec->write_event_data = write_event_data;
	set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
	}

	static const TypeInfo sclp_console_info = {
	.name = "sclplmconsole",
	.parent = TYPE_SCLP_EVENT,
	.instance_size = sizeof(SCLPConsoleLM),
	.class_init = console_class_init,
	.class_size = sizeof(SCLPEventClass),
	};

	static void register_types(void)
	{
	type_register_static(&sclp_console_info);
	}

	type_init(register_types)