qemu/hw/char/sclpconsole-lm.c
Richard Henderson 2f6cab053f hw/char: Constify VMState
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231221031652.119827-26-richard.henderson@linaro.org>
2023-12-29 11:17:30 +11:00

374 lines
10 KiB
C

/*
* 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 "qemu/osdep.h"
#include "qemu/thread.h"
#include "qemu/error-report.h"
#include "qemu/module.h"
#include "chardev/char-fe.h"
#include "hw/s390x/sclp.h"
#include "migration/vmstate.h"
#include "hw/s390x/event-facility.h"
#include "hw/qdev-properties.h"
#include "hw/qdev-properties-system.h"
#include "hw/s390x/ebcdic.h"
#include "qom/object.h"
#define SIZE_BUFFER 4096
#define NEWLINE "\n"
typedef struct OprtnsCommand {
EventBufferHeader header;
MDMSU message_unit;
char data[];
} QEMU_PACKED OprtnsCommand;
/* max size for line-mode data in 4K SCCB page */
#define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
struct SCLPConsoleLM {
SCLPEvent event;
CharBackend 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];
};
typedef struct SCLPConsoleLM SCLPConsoleLM;
#define TYPE_SCLPLM_CONSOLE "sclplmconsole"
DECLARE_INSTANCE_CHECKER(SCLPConsoleLM, SCLPLM_CONSOLE,
TYPE_SCLPLM_CONSOLE)
/*
* 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) {
/* XXX this blocks entire thread. Rewrite to use
* qemu_chr_fe_write and background I/O callbacks */
qemu_chr_fe_write_all(&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 sccb_mask_t send_mask(void)
{
return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
}
static sccb_mask_t 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 = SCLPLM_CONSOLE(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)
{
SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
if (!qemu_chr_fe_backend_connected(&scon->chr)) {
/* If there's no backend, we can just say we consumed all data. */
return len;
}
/* XXX this blocks entire thread. Rewrite to use
* qemu_chr_fe_write and background I/O callbacks */
return qemu_chr_fe_write_all(&scon->chr, buf, len);
}
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 = SCLPLM_CONSOLE(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 = (const 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 = SCLPLM_CONSOLE(event);
if (console_available) {
error_report("Multiple line-mode operator consoles are not supported");
return -1;
}
console_available = true;
qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
chr_read, NULL, NULL, scon, NULL, true);
return 0;
}
static void console_reset(DeviceState *dev)
{
SCLPEvent *event = SCLP_EVENT(dev);
SCLPConsoleLM *scon = SCLPLM_CONSOLE(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);
device_class_set_props(dc, console_properties);
dc->reset = console_reset;
dc->vmsd = &vmstate_sclplmconsole;
ec->init = console_init;
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 = TYPE_SCLPLM_CONSOLE,
.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)