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

ccw.c (23845B)


      1/*
      2 * vfio based subchannel assignment support
      3 *
      4 * Copyright 2017 IBM Corp.
      5 * Copyright 2019 Red Hat, Inc.
      6 *
      7 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
      8 *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
      9 *            Pierre Morel <pmorel@linux.vnet.ibm.com>
     10 *            Cornelia Huck <cohuck@redhat.com>
     11 *
     12 * This work is licensed under the terms of the GNU GPL, version 2 or (at
     13 * your option) any later version. See the COPYING file in the top-level
     14 * directory.
     15 */
     16
     17#include "qemu/osdep.h"
     18#include <linux/vfio.h>
     19#include <linux/vfio_ccw.h>
     20#include <sys/ioctl.h>
     21
     22#include "qapi/error.h"
     23#include "hw/vfio/vfio.h"
     24#include "hw/vfio/vfio-common.h"
     25#include "hw/s390x/s390-ccw.h"
     26#include "hw/s390x/vfio-ccw.h"
     27#include "hw/qdev-properties.h"
     28#include "hw/s390x/ccw-device.h"
     29#include "exec/address-spaces.h"
     30#include "qemu/error-report.h"
     31#include "qemu/main-loop.h"
     32#include "qemu/module.h"
     33
     34struct VFIOCCWDevice {
     35    S390CCWDevice cdev;
     36    VFIODevice vdev;
     37    uint64_t io_region_size;
     38    uint64_t io_region_offset;
     39    struct ccw_io_region *io_region;
     40    uint64_t async_cmd_region_size;
     41    uint64_t async_cmd_region_offset;
     42    struct ccw_cmd_region *async_cmd_region;
     43    uint64_t schib_region_size;
     44    uint64_t schib_region_offset;
     45    struct ccw_schib_region *schib_region;
     46    uint64_t crw_region_size;
     47    uint64_t crw_region_offset;
     48    struct ccw_crw_region *crw_region;
     49    EventNotifier io_notifier;
     50    EventNotifier crw_notifier;
     51    EventNotifier req_notifier;
     52    bool force_orb_pfch;
     53    bool warned_orb_pfch;
     54};
     55
     56static inline void warn_once_pfch(VFIOCCWDevice *vcdev, SubchDev *sch,
     57                                  const char *msg)
     58{
     59    warn_report_once_cond(&vcdev->warned_orb_pfch,
     60                          "vfio-ccw (devno %x.%x.%04x): %s",
     61                          sch->cssid, sch->ssid, sch->devno, msg);
     62}
     63
     64static void vfio_ccw_compute_needs_reset(VFIODevice *vdev)
     65{
     66    vdev->needs_reset = false;
     67}
     68
     69/*
     70 * We don't need vfio_hot_reset_multi and vfio_eoi operations for
     71 * vfio_ccw device now.
     72 */
     73struct VFIODeviceOps vfio_ccw_ops = {
     74    .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset,
     75};
     76
     77static IOInstEnding vfio_ccw_handle_request(SubchDev *sch)
     78{
     79    S390CCWDevice *cdev = sch->driver_data;
     80    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
     81    struct ccw_io_region *region = vcdev->io_region;
     82    int ret;
     83
     84    if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH) && vcdev->force_orb_pfch) {
     85        sch->orb.ctrl0 |= ORB_CTRL0_MASK_PFCH;
     86        warn_once_pfch(vcdev, sch, "PFCH flag forced");
     87    }
     88
     89    QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB));
     90    QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW));
     91    QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB));
     92
     93    memset(region, 0, sizeof(*region));
     94
     95    memcpy(region->orb_area, &sch->orb, sizeof(ORB));
     96    memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW));
     97
     98again:
     99    ret = pwrite(vcdev->vdev.fd, region,
    100                 vcdev->io_region_size, vcdev->io_region_offset);
    101    if (ret != vcdev->io_region_size) {
    102        if (errno == EAGAIN) {
    103            goto again;
    104        }
    105        error_report("vfio-ccw: write I/O region failed with errno=%d", errno);
    106        ret = errno ? -errno : -EFAULT;
    107    } else {
    108        ret = 0;
    109    }
    110    switch (ret) {
    111    case 0:
    112        return IOINST_CC_EXPECTED;
    113    case -EBUSY:
    114        return IOINST_CC_BUSY;
    115    case -ENODEV:
    116    case -EACCES:
    117        return IOINST_CC_NOT_OPERATIONAL;
    118    case -EFAULT:
    119    default:
    120        sch_gen_unit_exception(sch);
    121        css_inject_io_interrupt(sch);
    122        return IOINST_CC_EXPECTED;
    123    }
    124}
    125
    126static IOInstEnding vfio_ccw_handle_store(SubchDev *sch)
    127{
    128    S390CCWDevice *cdev = sch->driver_data;
    129    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
    130    SCHIB *schib = &sch->curr_status;
    131    struct ccw_schib_region *region = vcdev->schib_region;
    132    SCHIB *s;
    133    int ret;
    134
    135    /* schib region not available so nothing else to do */
    136    if (!region) {
    137        return IOINST_CC_EXPECTED;
    138    }
    139
    140    memset(region, 0, sizeof(*region));
    141    ret = pread(vcdev->vdev.fd, region, vcdev->schib_region_size,
    142                vcdev->schib_region_offset);
    143
    144    if (ret == -1) {
    145        /*
    146         * Device is probably damaged, but store subchannel does not
    147         * have a nonzero cc defined for this scenario.  Log an error,
    148         * and presume things are otherwise fine.
    149         */
    150        error_report("vfio-ccw: store region read failed with errno=%d", errno);
    151        return IOINST_CC_EXPECTED;
    152    }
    153
    154    /*
    155     * Selectively copy path-related bits of the SCHIB,
    156     * rather than copying the entire struct.
    157     */
    158    s = (SCHIB *)region->schib_area;
    159    schib->pmcw.pnom = s->pmcw.pnom;
    160    schib->pmcw.lpum = s->pmcw.lpum;
    161    schib->pmcw.pam = s->pmcw.pam;
    162    schib->pmcw.pom = s->pmcw.pom;
    163
    164    if (s->scsw.flags & SCSW_FLAGS_MASK_PNO) {
    165        schib->scsw.flags |= SCSW_FLAGS_MASK_PNO;
    166    }
    167
    168    return IOINST_CC_EXPECTED;
    169}
    170
    171static int vfio_ccw_handle_clear(SubchDev *sch)
    172{
    173    S390CCWDevice *cdev = sch->driver_data;
    174    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
    175    struct ccw_cmd_region *region = vcdev->async_cmd_region;
    176    int ret;
    177
    178    if (!vcdev->async_cmd_region) {
    179        /* Async command region not available, fall back to emulation */
    180        return -ENOSYS;
    181    }
    182
    183    memset(region, 0, sizeof(*region));
    184    region->command = VFIO_CCW_ASYNC_CMD_CSCH;
    185
    186again:
    187    ret = pwrite(vcdev->vdev.fd, region,
    188                 vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset);
    189    if (ret != vcdev->async_cmd_region_size) {
    190        if (errno == EAGAIN) {
    191            goto again;
    192        }
    193        error_report("vfio-ccw: write cmd region failed with errno=%d", errno);
    194        ret = errno ? -errno : -EFAULT;
    195    } else {
    196        ret = 0;
    197    }
    198    switch (ret) {
    199    case 0:
    200    case -ENODEV:
    201    case -EACCES:
    202        return ret;
    203    case -EFAULT:
    204    default:
    205        sch_gen_unit_exception(sch);
    206        css_inject_io_interrupt(sch);
    207        return 0;
    208    }
    209}
    210
    211static int vfio_ccw_handle_halt(SubchDev *sch)
    212{
    213    S390CCWDevice *cdev = sch->driver_data;
    214    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
    215    struct ccw_cmd_region *region = vcdev->async_cmd_region;
    216    int ret;
    217
    218    if (!vcdev->async_cmd_region) {
    219        /* Async command region not available, fall back to emulation */
    220        return -ENOSYS;
    221    }
    222
    223    memset(region, 0, sizeof(*region));
    224    region->command = VFIO_CCW_ASYNC_CMD_HSCH;
    225
    226again:
    227    ret = pwrite(vcdev->vdev.fd, region,
    228                 vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset);
    229    if (ret != vcdev->async_cmd_region_size) {
    230        if (errno == EAGAIN) {
    231            goto again;
    232        }
    233        error_report("vfio-ccw: write cmd region failed with errno=%d", errno);
    234        ret = errno ? -errno : -EFAULT;
    235    } else {
    236        ret = 0;
    237    }
    238    switch (ret) {
    239    case 0:
    240    case -EBUSY:
    241    case -ENODEV:
    242    case -EACCES:
    243        return ret;
    244    case -EFAULT:
    245    default:
    246        sch_gen_unit_exception(sch);
    247        css_inject_io_interrupt(sch);
    248        return 0;
    249    }
    250}
    251
    252static void vfio_ccw_reset(DeviceState *dev)
    253{
    254    CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
    255    S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
    256    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
    257
    258    ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
    259}
    260
    261static void vfio_ccw_crw_read(VFIOCCWDevice *vcdev)
    262{
    263    struct ccw_crw_region *region = vcdev->crw_region;
    264    CRW crw;
    265    int size;
    266
    267    /* Keep reading CRWs as long as data is returned */
    268    do {
    269        memset(region, 0, sizeof(*region));
    270        size = pread(vcdev->vdev.fd, region, vcdev->crw_region_size,
    271                     vcdev->crw_region_offset);
    272
    273        if (size == -1) {
    274            error_report("vfio-ccw: Read crw region failed with errno=%d",
    275                         errno);
    276            break;
    277        }
    278
    279        if (region->crw == 0) {
    280            /* No more CRWs to queue */
    281            break;
    282        }
    283
    284        memcpy(&crw, &region->crw, sizeof(CRW));
    285
    286        css_crw_add_to_queue(crw);
    287    } while (1);
    288}
    289
    290static void vfio_ccw_req_notifier_handler(void *opaque)
    291{
    292    VFIOCCWDevice *vcdev = opaque;
    293    Error *err = NULL;
    294
    295    if (!event_notifier_test_and_clear(&vcdev->req_notifier)) {
    296        return;
    297    }
    298
    299    qdev_unplug(DEVICE(vcdev), &err);
    300    if (err) {
    301        warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
    302    }
    303}
    304
    305static void vfio_ccw_crw_notifier_handler(void *opaque)
    306{
    307    VFIOCCWDevice *vcdev = opaque;
    308
    309    while (event_notifier_test_and_clear(&vcdev->crw_notifier)) {
    310        vfio_ccw_crw_read(vcdev);
    311    }
    312}
    313
    314static void vfio_ccw_io_notifier_handler(void *opaque)
    315{
    316    VFIOCCWDevice *vcdev = opaque;
    317    struct ccw_io_region *region = vcdev->io_region;
    318    S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev);
    319    CcwDevice *ccw_dev = CCW_DEVICE(cdev);
    320    SubchDev *sch = ccw_dev->sch;
    321    SCHIB *schib = &sch->curr_status;
    322    SCSW s;
    323    IRB irb;
    324    ESW esw;
    325    int size;
    326
    327    if (!event_notifier_test_and_clear(&vcdev->io_notifier)) {
    328        return;
    329    }
    330
    331    size = pread(vcdev->vdev.fd, region, vcdev->io_region_size,
    332                 vcdev->io_region_offset);
    333    if (size == -1) {
    334        switch (errno) {
    335        case ENODEV:
    336            /* Generate a deferred cc 3 condition. */
    337            schib->scsw.flags |= SCSW_FLAGS_MASK_CC;
    338            schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
    339            schib->scsw.ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND);
    340            goto read_err;
    341        case EFAULT:
    342            /* Memory problem, generate channel data check. */
    343            schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
    344            schib->scsw.cstat = SCSW_CSTAT_DATA_CHECK;
    345            schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
    346            schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
    347                       SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
    348            goto read_err;
    349        default:
    350            /* Error, generate channel program check. */
    351            schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
    352            schib->scsw.cstat = SCSW_CSTAT_PROG_CHECK;
    353            schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
    354            schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
    355                       SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
    356            goto read_err;
    357        }
    358    } else if (size != vcdev->io_region_size) {
    359        /* Information transfer error, generate channel-control check. */
    360        schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
    361        schib->scsw.cstat = SCSW_CSTAT_CHN_CTRL_CHK;
    362        schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
    363        schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
    364                   SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
    365        goto read_err;
    366    }
    367
    368    memcpy(&irb, region->irb_area, sizeof(IRB));
    369
    370    /* Update control block via irb. */
    371    s = schib->scsw;
    372    copy_scsw_to_guest(&s, &irb.scsw);
    373    schib->scsw = s;
    374
    375    copy_esw_to_guest(&esw, &irb.esw);
    376    sch->esw = esw;
    377
    378    /* If a uint check is pending, copy sense data. */
    379    if ((schib->scsw.dstat & SCSW_DSTAT_UNIT_CHECK) &&
    380        (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE)) {
    381        memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw));
    382    }
    383
    384read_err:
    385    css_inject_io_interrupt(sch);
    386}
    387
    388static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
    389                                           unsigned int irq,
    390                                           Error **errp)
    391{
    392    VFIODevice *vdev = &vcdev->vdev;
    393    struct vfio_irq_info *irq_info;
    394    size_t argsz;
    395    int fd;
    396    EventNotifier *notifier;
    397    IOHandler *fd_read;
    398
    399    switch (irq) {
    400    case VFIO_CCW_IO_IRQ_INDEX:
    401        notifier = &vcdev->io_notifier;
    402        fd_read = vfio_ccw_io_notifier_handler;
    403        break;
    404    case VFIO_CCW_CRW_IRQ_INDEX:
    405        notifier = &vcdev->crw_notifier;
    406        fd_read = vfio_ccw_crw_notifier_handler;
    407        break;
    408    case VFIO_CCW_REQ_IRQ_INDEX:
    409        notifier = &vcdev->req_notifier;
    410        fd_read = vfio_ccw_req_notifier_handler;
    411        break;
    412    default:
    413        error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
    414        return;
    415    }
    416
    417    if (vdev->num_irqs < irq + 1) {
    418        error_setg(errp, "vfio: IRQ %u not available (number of irqs %u)",
    419                   irq, vdev->num_irqs);
    420        return;
    421    }
    422
    423    argsz = sizeof(*irq_info);
    424    irq_info = g_malloc0(argsz);
    425    irq_info->index = irq;
    426    irq_info->argsz = argsz;
    427    if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
    428              irq_info) < 0 || irq_info->count < 1) {
    429        error_setg_errno(errp, errno, "vfio: Error getting irq info");
    430        goto out_free_info;
    431    }
    432
    433    if (event_notifier_init(notifier, 0)) {
    434        error_setg_errno(errp, errno,
    435                         "vfio: Unable to init event notifier for irq (%d)",
    436                         irq);
    437        goto out_free_info;
    438    }
    439
    440    fd = event_notifier_get_fd(notifier);
    441    qemu_set_fd_handler(fd, fd_read, NULL, vcdev);
    442
    443    if (vfio_set_irq_signaling(vdev, irq, 0,
    444                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
    445        qemu_set_fd_handler(fd, NULL, NULL, vcdev);
    446        event_notifier_cleanup(notifier);
    447    }
    448
    449out_free_info:
    450    g_free(irq_info);
    451}
    452
    453static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
    454                                             unsigned int irq)
    455{
    456    Error *err = NULL;
    457    EventNotifier *notifier;
    458
    459    switch (irq) {
    460    case VFIO_CCW_IO_IRQ_INDEX:
    461        notifier = &vcdev->io_notifier;
    462        break;
    463    case VFIO_CCW_CRW_IRQ_INDEX:
    464        notifier = &vcdev->crw_notifier;
    465        break;
    466    case VFIO_CCW_REQ_IRQ_INDEX:
    467        notifier = &vcdev->req_notifier;
    468        break;
    469    default:
    470        error_report("vfio: Unsupported device irq(%d)", irq);
    471        return;
    472    }
    473
    474    if (vfio_set_irq_signaling(&vcdev->vdev, irq, 0,
    475                               VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
    476        warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
    477    }
    478
    479    qemu_set_fd_handler(event_notifier_get_fd(notifier),
    480                        NULL, NULL, vcdev);
    481    event_notifier_cleanup(notifier);
    482}
    483
    484static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
    485{
    486    VFIODevice *vdev = &vcdev->vdev;
    487    struct vfio_region_info *info;
    488    int ret;
    489
    490    /* Sanity check device */
    491    if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) {
    492        error_setg(errp, "vfio: Um, this isn't a vfio-ccw device");
    493        return;
    494    }
    495
    496    /*
    497     * We always expect at least the I/O region to be present. We also
    498     * may have a variable number of regions governed by capabilities.
    499     */
    500    if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) {
    501        error_setg(errp, "vfio: too few regions (%u), expected at least %u",
    502                   vdev->num_regions, VFIO_CCW_CONFIG_REGION_INDEX + 1);
    503        return;
    504    }
    505
    506    ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info);
    507    if (ret) {
    508        error_setg_errno(errp, -ret, "vfio: Error getting config info");
    509        return;
    510    }
    511
    512    vcdev->io_region_size = info->size;
    513    if (sizeof(*vcdev->io_region) != vcdev->io_region_size) {
    514        error_setg(errp, "vfio: Unexpected size of the I/O region");
    515        goto out_err;
    516    }
    517
    518    vcdev->io_region_offset = info->offset;
    519    vcdev->io_region = g_malloc0(info->size);
    520    g_free(info);
    521
    522    /* check for the optional async command region */
    523    ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
    524                                   VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, &info);
    525    if (!ret) {
    526        vcdev->async_cmd_region_size = info->size;
    527        if (sizeof(*vcdev->async_cmd_region) != vcdev->async_cmd_region_size) {
    528            error_setg(errp, "vfio: Unexpected size of the async cmd region");
    529            goto out_err;
    530        }
    531        vcdev->async_cmd_region_offset = info->offset;
    532        vcdev->async_cmd_region = g_malloc0(info->size);
    533        g_free(info);
    534    }
    535
    536    ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
    537                                   VFIO_REGION_SUBTYPE_CCW_SCHIB, &info);
    538    if (!ret) {
    539        vcdev->schib_region_size = info->size;
    540        if (sizeof(*vcdev->schib_region) != vcdev->schib_region_size) {
    541            error_setg(errp, "vfio: Unexpected size of the schib region");
    542            goto out_err;
    543        }
    544        vcdev->schib_region_offset = info->offset;
    545        vcdev->schib_region = g_malloc(info->size);
    546        g_free(info);
    547    }
    548
    549    ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
    550                                   VFIO_REGION_SUBTYPE_CCW_CRW, &info);
    551
    552    if (!ret) {
    553        vcdev->crw_region_size = info->size;
    554        if (sizeof(*vcdev->crw_region) != vcdev->crw_region_size) {
    555            error_setg(errp, "vfio: Unexpected size of the CRW region");
    556            goto out_err;
    557        }
    558        vcdev->crw_region_offset = info->offset;
    559        vcdev->crw_region = g_malloc(info->size);
    560        g_free(info);
    561    }
    562
    563    return;
    564
    565out_err:
    566    g_free(vcdev->crw_region);
    567    g_free(vcdev->schib_region);
    568    g_free(vcdev->async_cmd_region);
    569    g_free(vcdev->io_region);
    570    g_free(info);
    571    return;
    572}
    573
    574static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
    575{
    576    g_free(vcdev->crw_region);
    577    g_free(vcdev->schib_region);
    578    g_free(vcdev->async_cmd_region);
    579    g_free(vcdev->io_region);
    580}
    581
    582static void vfio_ccw_put_device(VFIOCCWDevice *vcdev)
    583{
    584    g_free(vcdev->vdev.name);
    585    vfio_put_base_device(&vcdev->vdev);
    586}
    587
    588static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
    589                                Error **errp)
    590{
    591    char *name = g_strdup_printf("%x.%x.%04x", vcdev->cdev.hostid.cssid,
    592                                 vcdev->cdev.hostid.ssid,
    593                                 vcdev->cdev.hostid.devid);
    594    VFIODevice *vbasedev;
    595
    596    QLIST_FOREACH(vbasedev, &group->device_list, next) {
    597        if (strcmp(vbasedev->name, name) == 0) {
    598            error_setg(errp, "vfio: subchannel %s has already been attached",
    599                       name);
    600            goto out_err;
    601        }
    602    }
    603
    604    /*
    605     * All vfio-ccw devices are believed to operate in a way compatible with
    606     * discarding of memory in RAM blocks, ie. pages pinned in the host are
    607     * in the current working set of the guest driver and therefore never
    608     * overlap e.g., with pages available to the guest balloon driver.  This
    609     * needs to be set before vfio_get_device() for vfio common to handle
    610     * ram_block_discard_disable().
    611     */
    612    vcdev->vdev.ram_block_discard_allowed = true;
    613
    614    if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) {
    615        goto out_err;
    616    }
    617
    618    vcdev->vdev.ops = &vfio_ccw_ops;
    619    vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW;
    620    vcdev->vdev.name = name;
    621    vcdev->vdev.dev = &vcdev->cdev.parent_obj.parent_obj;
    622
    623    return;
    624
    625out_err:
    626    g_free(name);
    627}
    628
    629static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp)
    630{
    631    char *tmp, group_path[PATH_MAX];
    632    ssize_t len;
    633    int groupid;
    634
    635    tmp = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/%s/iommu_group",
    636                          cdev->hostid.cssid, cdev->hostid.ssid,
    637                          cdev->hostid.devid, cdev->mdevid);
    638    len = readlink(tmp, group_path, sizeof(group_path));
    639    g_free(tmp);
    640
    641    if (len <= 0 || len >= sizeof(group_path)) {
    642        error_setg(errp, "vfio: no iommu_group found");
    643        return NULL;
    644    }
    645
    646    group_path[len] = 0;
    647
    648    if (sscanf(basename(group_path), "%d", &groupid) != 1) {
    649        error_setg(errp, "vfio: failed to read %s", group_path);
    650        return NULL;
    651    }
    652
    653    return vfio_get_group(groupid, &address_space_memory, errp);
    654}
    655
    656static void vfio_ccw_realize(DeviceState *dev, Error **errp)
    657{
    658    VFIOGroup *group;
    659    CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
    660    S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
    661    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
    662    S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
    663    Error *err = NULL;
    664
    665    /* Call the class init function for subchannel. */
    666    if (cdc->realize) {
    667        cdc->realize(cdev, vcdev->vdev.sysfsdev, &err);
    668        if (err) {
    669            goto out_err_propagate;
    670        }
    671    }
    672
    673    group = vfio_ccw_get_group(cdev, &err);
    674    if (!group) {
    675        goto out_group_err;
    676    }
    677
    678    vfio_ccw_get_device(group, vcdev, &err);
    679    if (err) {
    680        goto out_device_err;
    681    }
    682
    683    vfio_ccw_get_region(vcdev, &err);
    684    if (err) {
    685        goto out_region_err;
    686    }
    687
    688    vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err);
    689    if (err) {
    690        goto out_io_notifier_err;
    691    }
    692
    693    if (vcdev->crw_region) {
    694        vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err);
    695        if (err) {
    696            goto out_irq_notifier_err;
    697        }
    698    }
    699
    700    vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err);
    701    if (err) {
    702        /*
    703         * Report this error, but do not make it a failing condition.
    704         * Lack of this IRQ in the host does not prevent normal operation.
    705         */
    706        error_report_err(err);
    707    }
    708
    709    return;
    710
    711out_irq_notifier_err:
    712    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX);
    713    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
    714    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
    715out_io_notifier_err:
    716    vfio_ccw_put_region(vcdev);
    717out_region_err:
    718    vfio_ccw_put_device(vcdev);
    719out_device_err:
    720    vfio_put_group(group);
    721out_group_err:
    722    if (cdc->unrealize) {
    723        cdc->unrealize(cdev);
    724    }
    725out_err_propagate:
    726    error_propagate(errp, err);
    727}
    728
    729static void vfio_ccw_unrealize(DeviceState *dev)
    730{
    731    CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
    732    S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
    733    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
    734    S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
    735    VFIOGroup *group = vcdev->vdev.group;
    736
    737    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX);
    738    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
    739    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
    740    vfio_ccw_put_region(vcdev);
    741    vfio_ccw_put_device(vcdev);
    742    vfio_put_group(group);
    743
    744    if (cdc->unrealize) {
    745        cdc->unrealize(cdev);
    746    }
    747}
    748
    749static Property vfio_ccw_properties[] = {
    750    DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev),
    751    DEFINE_PROP_BOOL("force-orb-pfch", VFIOCCWDevice, force_orb_pfch, false),
    752    DEFINE_PROP_END_OF_LIST(),
    753};
    754
    755static const VMStateDescription vfio_ccw_vmstate = {
    756    .name = "vfio-ccw",
    757    .unmigratable = 1,
    758};
    759
    760static void vfio_ccw_class_init(ObjectClass *klass, void *data)
    761{
    762    DeviceClass *dc = DEVICE_CLASS(klass);
    763    S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass);
    764
    765    device_class_set_props(dc, vfio_ccw_properties);
    766    dc->vmsd = &vfio_ccw_vmstate;
    767    dc->desc = "VFIO-based subchannel assignment";
    768    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
    769    dc->realize = vfio_ccw_realize;
    770    dc->unrealize = vfio_ccw_unrealize;
    771    dc->reset = vfio_ccw_reset;
    772
    773    cdc->handle_request = vfio_ccw_handle_request;
    774    cdc->handle_halt = vfio_ccw_handle_halt;
    775    cdc->handle_clear = vfio_ccw_handle_clear;
    776    cdc->handle_store = vfio_ccw_handle_store;
    777}
    778
    779static const TypeInfo vfio_ccw_info = {
    780    .name = TYPE_VFIO_CCW,
    781    .parent = TYPE_S390_CCW,
    782    .instance_size = sizeof(VFIOCCWDevice),
    783    .class_init = vfio_ccw_class_init,
    784};
    785
    786static void register_vfio_ccw_type(void)
    787{
    788    type_register_static(&vfio_ccw_info);
    789}
    790
    791type_init(register_vfio_ccw_type)