cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

sclpconsole-lm.c (10461B)


      1/*
      2 * SCLP event types
      3 *    Operations Command - Line Mode input
      4 *    Message            - Line Mode output
      5 *
      6 * Copyright IBM, Corp. 2013
      7 *
      8 * Authors:
      9 *  Heinz Graalfs <graalfs@linux.vnet.ibm.com>
     10 *
     11 * This work is licensed under the terms of the GNU GPL, version 2 or (at your
     12 * option) any later version.  See the COPYING file in the top-level directory.
     13 *
     14 */
     15
     16#include "qemu/osdep.h"
     17#include "qemu/thread.h"
     18#include "qemu/error-report.h"
     19#include "qemu/module.h"
     20#include "chardev/char-fe.h"
     21
     22#include "hw/s390x/sclp.h"
     23#include "migration/vmstate.h"
     24#include "hw/s390x/event-facility.h"
     25#include "hw/qdev-properties.h"
     26#include "hw/qdev-properties-system.h"
     27#include "hw/s390x/ebcdic.h"
     28#include "qom/object.h"
     29
     30#define SIZE_BUFFER 4096
     31#define NEWLINE     "\n"
     32
     33typedef struct OprtnsCommand {
     34    EventBufferHeader header;
     35    MDMSU message_unit;
     36    char data[];
     37} QEMU_PACKED OprtnsCommand;
     38
     39/* max size for line-mode data in 4K SCCB page */
     40#define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
     41
     42struct SCLPConsoleLM {
     43    SCLPEvent event;
     44    CharBackend chr;
     45    bool echo;                  /* immediate echo of input if true        */
     46    uint32_t write_errors;      /* errors writing to char layer           */
     47    uint32_t length;            /* length of byte stream in buffer        */
     48    uint8_t buf[SIZE_CONSOLE_BUFFER];
     49};
     50typedef struct SCLPConsoleLM SCLPConsoleLM;
     51
     52#define TYPE_SCLPLM_CONSOLE "sclplmconsole"
     53DECLARE_INSTANCE_CHECKER(SCLPConsoleLM, SCLPLM_CONSOLE,
     54                         TYPE_SCLPLM_CONSOLE)
     55
     56/*
     57*  Character layer call-back functions
     58 *
     59 * Allow 1 character at a time
     60 *
     61 * Accumulate bytes from character layer in console buffer,
     62 * event_pending is set when a newline character is encountered
     63 *
     64 * The maximum command line length is limited by the maximum
     65 * space available in an SCCB. Line mode console input is sent
     66 * truncated to the guest in case it doesn't fit into the SCCB.
     67 */
     68
     69static int chr_can_read(void *opaque)
     70{
     71    SCLPConsoleLM *scon = opaque;
     72
     73    if (scon->event.event_pending) {
     74        return 0;
     75    }
     76    return 1;
     77}
     78
     79static void chr_read(void *opaque, const uint8_t *buf, int size)
     80{
     81    SCLPConsoleLM *scon = opaque;
     82
     83    assert(size == 1);
     84
     85    if (*buf == '\r' || *buf == '\n') {
     86        scon->event.event_pending = true;
     87        sclp_service_interrupt(0);
     88        return;
     89    }
     90    if (scon->length == SIZE_CONSOLE_BUFFER) {
     91        /* Eat the character, but still process CR and LF.  */
     92        return;
     93    }
     94    scon->buf[scon->length] = *buf;
     95    scon->length += 1;
     96    if (scon->echo) {
     97        /* XXX this blocks entire thread. Rewrite to use
     98         * qemu_chr_fe_write and background I/O callbacks */
     99        qemu_chr_fe_write_all(&scon->chr, buf, size);
    100    }
    101}
    102
    103/* functions to be called by event facility */
    104
    105static bool can_handle_event(uint8_t type)
    106{
    107    return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
    108}
    109
    110static sccb_mask_t send_mask(void)
    111{
    112    return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
    113}
    114
    115static sccb_mask_t receive_mask(void)
    116{
    117    return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
    118}
    119
    120/*
    121 * Triggered by SCLP's read_event_data
    122 * - convert ASCII byte stream to EBCDIC and
    123 * - copy converted data into provided (SCLP) buffer
    124 */
    125static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
    126                            int avail)
    127{
    128    int len;
    129
    130    SCLPConsoleLM *cons = SCLPLM_CONSOLE(event);
    131
    132    len = cons->length;
    133    /* data need to fit into provided SCLP buffer */
    134    if (len > avail) {
    135        return 1;
    136    }
    137
    138    ebcdic_put(buf, (char *)&cons->buf, len);
    139    *size = len;
    140    cons->length = 0;
    141    /* data provided and no more data pending */
    142    event->event_pending = false;
    143    qemu_notify_event();
    144    return 0;
    145}
    146
    147static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
    148                           int *slen)
    149{
    150    int avail, rc;
    151    size_t src_len;
    152    uint8_t *to;
    153    OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
    154
    155    if (!event->event_pending) {
    156        /* no data pending */
    157        return 0;
    158    }
    159
    160    to = (uint8_t *)&oc->data;
    161    avail = *slen - sizeof(OprtnsCommand);
    162    rc = get_console_data(event, to, &src_len, avail);
    163    if (rc) {
    164        /* data didn't fit, try next SCCB */
    165        return 1;
    166    }
    167
    168    oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
    169    oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
    170
    171    oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
    172    oc->message_unit.cpmsu.length =
    173        cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
    174
    175    oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
    176    oc->message_unit.text_command.length =
    177        cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
    178
    179    oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
    180    oc->message_unit.self_def_text_message.length =
    181        cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
    182
    183    oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
    184    oc->message_unit.text_message.length =
    185        cpu_to_be16(sizeof(GdsSubvector) + src_len);
    186
    187    oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
    188    oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
    189    *slen = avail - src_len;
    190
    191    return 1;
    192}
    193
    194/*
    195 * Triggered by SCLP's write_event_data
    196 *  - write console data to character layer
    197 *  returns < 0 if an error occurred
    198 */
    199static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
    200{
    201    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
    202
    203    if (!qemu_chr_fe_backend_connected(&scon->chr)) {
    204        /* If there's no backend, we can just say we consumed all data. */
    205        return len;
    206    }
    207
    208    /* XXX this blocks entire thread. Rewrite to use
    209     * qemu_chr_fe_write and background I/O callbacks */
    210    return qemu_chr_fe_write_all(&scon->chr, buf, len);
    211}
    212
    213static int process_mdb(SCLPEvent *event, MDBO *mdbo)
    214{
    215    int rc;
    216    int len;
    217    uint8_t buffer[SIZE_BUFFER];
    218
    219    len = be16_to_cpu(mdbo->length);
    220    len -= sizeof(mdbo->length) + sizeof(mdbo->type)
    221            + sizeof(mdbo->mto.line_type_flags)
    222            + sizeof(mdbo->mto.alarm_control)
    223            + sizeof(mdbo->mto._reserved);
    224
    225    assert(len <= SIZE_BUFFER);
    226
    227    /* convert EBCDIC SCLP contents to ASCII console message */
    228    ascii_put(buffer, mdbo->mto.message, len);
    229    rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
    230    if (rc < 0) {
    231        return rc;
    232    }
    233    return write_console_data(event, buffer, len);
    234}
    235
    236static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
    237{
    238    int len;
    239    int written;
    240    int errors = 0;
    241    MDBO *mdbo;
    242    SclpMsg *data = (SclpMsg *) ebh;
    243    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
    244
    245    len = be16_to_cpu(data->mdb.header.length);
    246    if (len < sizeof(data->mdb.header)) {
    247        return SCLP_RC_INCONSISTENT_LENGTHS;
    248    }
    249    len -= sizeof(data->mdb.header);
    250
    251    /* first check message buffers */
    252    mdbo = data->mdb.mdbo;
    253    while (len > 0) {
    254        if (be16_to_cpu(mdbo->length) > len
    255                || be16_to_cpu(mdbo->length) == 0) {
    256            return SCLP_RC_INCONSISTENT_LENGTHS;
    257        }
    258        len -= be16_to_cpu(mdbo->length);
    259        mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
    260    }
    261
    262    /* then execute */
    263    len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
    264    mdbo = data->mdb.mdbo;
    265    while (len > 0) {
    266        switch (be16_to_cpu(mdbo->type)) {
    267        case MESSAGE_TEXT:
    268            /* message text object */
    269            written = process_mdb(event, mdbo);
    270            if (written < 0) {
    271                /* character layer error */
    272                errors++;
    273            }
    274            break;
    275        default: /* ignore */
    276            break;
    277        }
    278        len -= be16_to_cpu(mdbo->length);
    279        mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
    280    }
    281    if (errors) {
    282        scon->write_errors += errors;
    283    }
    284    data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
    285
    286    return SCLP_RC_NORMAL_COMPLETION;
    287}
    288
    289/* functions for live migration */
    290
    291static const VMStateDescription vmstate_sclplmconsole = {
    292    .name = "sclplmconsole",
    293    .version_id = 0,
    294    .minimum_version_id = 0,
    295    .fields = (VMStateField[]) {
    296        VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
    297        VMSTATE_UINT32(write_errors, SCLPConsoleLM),
    298        VMSTATE_UINT32(length, SCLPConsoleLM),
    299        VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
    300        VMSTATE_END_OF_LIST()
    301     }
    302};
    303
    304/* qemu object creation and initialization functions */
    305
    306/* tell character layer our call-back functions */
    307
    308static int console_init(SCLPEvent *event)
    309{
    310    static bool console_available;
    311
    312    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
    313
    314    if (console_available) {
    315        error_report("Multiple line-mode operator consoles are not supported");
    316        return -1;
    317    }
    318    console_available = true;
    319
    320    qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
    321                             chr_read, NULL, NULL, scon, NULL, true);
    322
    323    return 0;
    324}
    325
    326static void console_reset(DeviceState *dev)
    327{
    328   SCLPEvent *event = SCLP_EVENT(dev);
    329   SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
    330
    331   event->event_pending = false;
    332   scon->length = 0;
    333   scon->write_errors = 0;
    334}
    335
    336static Property console_properties[] = {
    337    DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
    338    DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
    339    DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
    340    DEFINE_PROP_END_OF_LIST(),
    341};
    342
    343static void console_class_init(ObjectClass *klass, void *data)
    344{
    345    DeviceClass *dc = DEVICE_CLASS(klass);
    346    SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
    347
    348    device_class_set_props(dc, console_properties);
    349    dc->reset = console_reset;
    350    dc->vmsd = &vmstate_sclplmconsole;
    351    ec->init = console_init;
    352    ec->get_send_mask = send_mask;
    353    ec->get_receive_mask = receive_mask;
    354    ec->can_handle_event = can_handle_event;
    355    ec->read_event_data = read_event_data;
    356    ec->write_event_data = write_event_data;
    357    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
    358}
    359
    360static const TypeInfo sclp_console_info = {
    361    .name          = TYPE_SCLPLM_CONSOLE,
    362    .parent        = TYPE_SCLP_EVENT,
    363    .instance_size = sizeof(SCLPConsoleLM),
    364    .class_init    = console_class_init,
    365    .class_size    = sizeof(SCLPEventClass),
    366};
    367
    368static void register_types(void)
    369{
    370    type_register_static(&sclp_console_info);
    371}
    372
    373type_init(register_types)