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.c (8333B)


      1/*
      2 * SCLP event type
      3 *    Ascii Console Data (VT220 Console)
      4 *
      5 * Copyright IBM, Corp. 2012
      6 *
      7 * Authors:
      8 *  Heinz Graalfs <graalfs@de.ibm.com>
      9 *
     10 * This work is licensed under the terms of the GNU GPL, version 2 or (at your
     11 * option) any later version.  See the COPYING file in the top-level directory.
     12 *
     13 */
     14
     15#include "qemu/osdep.h"
     16#include "qemu/thread.h"
     17#include "qemu/error-report.h"
     18#include "qemu/module.h"
     19
     20#include "hw/s390x/sclp.h"
     21#include "migration/vmstate.h"
     22#include "hw/qdev-properties.h"
     23#include "hw/qdev-properties-system.h"
     24#include "hw/s390x/event-facility.h"
     25#include "chardev/char-fe.h"
     26#include "qom/object.h"
     27
     28typedef struct ASCIIConsoleData {
     29    EventBufferHeader ebh;
     30    char data[];
     31} QEMU_PACKED ASCIIConsoleData;
     32
     33/* max size for ASCII data in 4K SCCB page */
     34#define SIZE_BUFFER_VT220 4080
     35
     36struct SCLPConsole {
     37    SCLPEvent event;
     38    CharBackend chr;
     39    uint8_t iov[SIZE_BUFFER_VT220];
     40    uint32_t iov_sclp;      /* offset in buf for SCLP read operation       */
     41    uint32_t iov_bs;        /* offset in buf for char layer read operation */
     42    uint32_t iov_data_len;  /* length of byte stream in buffer             */
     43    uint32_t iov_sclp_rest; /* length of byte stream not read via SCLP     */
     44    bool notify;            /* qemu_notify_event() req'd if true           */
     45};
     46typedef struct SCLPConsole SCLPConsole;
     47
     48#define TYPE_SCLP_CONSOLE "sclpconsole"
     49DECLARE_INSTANCE_CHECKER(SCLPConsole, SCLP_CONSOLE,
     50                         TYPE_SCLP_CONSOLE)
     51
     52/* character layer call-back functions */
     53
     54/* Return number of bytes that fit into iov buffer */
     55static int chr_can_read(void *opaque)
     56{
     57    SCLPConsole *scon = opaque;
     58    int avail = SIZE_BUFFER_VT220 - scon->iov_data_len;
     59
     60    if (avail == 0) {
     61        scon->notify = true;
     62    }
     63    return avail;
     64}
     65
     66/* Send data from a char device over to the guest */
     67static void chr_read(void *opaque, const uint8_t *buf, int size)
     68{
     69    SCLPConsole *scon = opaque;
     70
     71    assert(scon);
     72    /* read data must fit into current buffer */
     73    assert(size <= SIZE_BUFFER_VT220 - scon->iov_data_len);
     74
     75    /* put byte-stream from character layer into buffer */
     76    memcpy(&scon->iov[scon->iov_bs], buf, size);
     77    scon->iov_data_len += size;
     78    scon->iov_sclp_rest += size;
     79    scon->iov_bs += size;
     80    scon->event.event_pending = true;
     81    sclp_service_interrupt(0);
     82}
     83
     84/* functions to be called by event facility */
     85
     86static bool can_handle_event(uint8_t type)
     87{
     88    return type == SCLP_EVENT_ASCII_CONSOLE_DATA;
     89}
     90
     91static sccb_mask_t send_mask(void)
     92{
     93    return SCLP_EVENT_MASK_MSG_ASCII;
     94}
     95
     96static sccb_mask_t receive_mask(void)
     97{
     98    return SCLP_EVENT_MASK_MSG_ASCII;
     99}
    100
    101/* triggered by SCLP's read_event_data -
    102 * copy console data byte-stream into provided (SCLP) buffer
    103 */
    104static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
    105                             int avail)
    106{
    107    SCLPConsole *cons = SCLP_CONSOLE(event);
    108
    109    /* first byte is hex 0 saying an ascii string follows */
    110    *buf++ = '\0';
    111    avail--;
    112    /* if all data fit into provided SCLP buffer */
    113    if (avail >= cons->iov_sclp_rest) {
    114        /* copy character byte-stream to SCLP buffer */
    115        memcpy(buf, &cons->iov[cons->iov_sclp], cons->iov_sclp_rest);
    116        *size = cons->iov_sclp_rest + 1;
    117        cons->iov_sclp = 0;
    118        cons->iov_bs = 0;
    119        cons->iov_data_len = 0;
    120        cons->iov_sclp_rest = 0;
    121        event->event_pending = false;
    122        /* data provided and no more data pending */
    123    } else {
    124        /* if provided buffer is too small, just copy part */
    125        memcpy(buf, &cons->iov[cons->iov_sclp], avail);
    126        *size = avail + 1;
    127        cons->iov_sclp_rest -= avail;
    128        cons->iov_sclp += avail;
    129        /* more data pending */
    130    }
    131    if (cons->notify) {
    132        cons->notify = false;
    133        qemu_notify_event();
    134    }
    135}
    136
    137static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
    138                           int *slen)
    139{
    140    int avail;
    141    size_t src_len;
    142    uint8_t *to;
    143    ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
    144
    145    if (!event->event_pending) {
    146        /* no data pending */
    147        return 0;
    148    }
    149
    150    to = (uint8_t *)&acd->data;
    151    avail = *slen - sizeof(ASCIIConsoleData);
    152    get_console_data(event, to, &src_len, avail);
    153
    154    acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
    155    acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
    156    acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
    157    *slen = avail - src_len;
    158
    159    return 1;
    160}
    161
    162/* triggered by SCLP's write_event_data
    163 *  - write console data to character layer
    164 *  returns < 0 if an error occurred
    165 */
    166static ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
    167                                  size_t len)
    168{
    169    SCLPConsole *scon = SCLP_CONSOLE(event);
    170
    171    if (!qemu_chr_fe_backend_connected(&scon->chr)) {
    172        /* If there's no backend, we can just say we consumed all data. */
    173        return len;
    174    }
    175
    176    /* XXX this blocks entire thread. Rewrite to use
    177     * qemu_chr_fe_write and background I/O callbacks */
    178    return qemu_chr_fe_write_all(&scon->chr, buf, len);
    179}
    180
    181static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
    182{
    183    int rc;
    184    int length;
    185    ssize_t written;
    186    ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
    187
    188    length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
    189    written = write_console_data(event, (uint8_t *)acd->data, length);
    190
    191    rc = SCLP_RC_NORMAL_COMPLETION;
    192    /* set event buffer accepted flag */
    193    evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;
    194
    195    /* written will be zero if a pty is not connected - don't treat as error */
    196    if (written < 0) {
    197        /* event buffer not accepted due to error in character layer */
    198        evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
    199        rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
    200    }
    201
    202    return rc;
    203}
    204
    205static const VMStateDescription vmstate_sclpconsole = {
    206    .name = "sclpconsole",
    207    .version_id = 0,
    208    .minimum_version_id = 0,
    209    .fields = (VMStateField[]) {
    210        VMSTATE_BOOL(event.event_pending, SCLPConsole),
    211        VMSTATE_UINT8_ARRAY(iov, SCLPConsole, SIZE_BUFFER_VT220),
    212        VMSTATE_UINT32(iov_sclp, SCLPConsole),
    213        VMSTATE_UINT32(iov_bs, SCLPConsole),
    214        VMSTATE_UINT32(iov_data_len, SCLPConsole),
    215        VMSTATE_UINT32(iov_sclp_rest, SCLPConsole),
    216        VMSTATE_END_OF_LIST()
    217     }
    218};
    219
    220/* qemu object creation and initialization functions */
    221
    222/* tell character layer our call-back functions */
    223
    224static int console_init(SCLPEvent *event)
    225{
    226    static bool console_available;
    227
    228    SCLPConsole *scon = SCLP_CONSOLE(event);
    229
    230    if (console_available) {
    231        error_report("Multiple VT220 operator consoles are not supported");
    232        return -1;
    233    }
    234    console_available = true;
    235    qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
    236                             chr_read, NULL, NULL, scon, NULL, true);
    237
    238    return 0;
    239}
    240
    241static void console_reset(DeviceState *dev)
    242{
    243   SCLPEvent *event = SCLP_EVENT(dev);
    244   SCLPConsole *scon = SCLP_CONSOLE(event);
    245
    246   event->event_pending = false;
    247   scon->iov_sclp = 0;
    248   scon->iov_bs = 0;
    249   scon->iov_data_len = 0;
    250   scon->iov_sclp_rest = 0;
    251   scon->notify = false;
    252}
    253
    254static Property console_properties[] = {
    255    DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
    256    DEFINE_PROP_END_OF_LIST(),
    257};
    258
    259static void console_class_init(ObjectClass *klass, void *data)
    260{
    261    DeviceClass *dc = DEVICE_CLASS(klass);
    262    SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
    263
    264    device_class_set_props(dc, console_properties);
    265    dc->reset = console_reset;
    266    dc->vmsd = &vmstate_sclpconsole;
    267    ec->init = console_init;
    268    ec->get_send_mask = send_mask;
    269    ec->get_receive_mask = receive_mask;
    270    ec->can_handle_event = can_handle_event;
    271    ec->read_event_data = read_event_data;
    272    ec->write_event_data = write_event_data;
    273    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
    274}
    275
    276static const TypeInfo sclp_console_info = {
    277    .name          = TYPE_SCLP_CONSOLE,
    278    .parent        = TYPE_SCLP_EVENT,
    279    .instance_size = sizeof(SCLPConsole),
    280    .class_init    = console_class_init,
    281    .class_size    = sizeof(SCLPEventClass),
    282};
    283
    284static void register_types(void)
    285{
    286    type_register_static(&sclp_console_info);
    287}
    288
    289type_init(register_types)