LXR qemu/hw/vfio/ap.c

   1/*
   2 * VFIO based AP matrix device assignment
   3 *
   4 * Copyright 2018 IBM Corp.
   5 * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
   6 *            Halil Pasic <pasic@linux.ibm.com>
   7 *
   8 * This work is licensed under the terms of the GNU GPL, version 2 or (at
   9 * your option) any later version. See the COPYING file in the top-level
  10 * directory.
  11 */
  12
  13#include "qemu/osdep.h"
  14#include <linux/vfio.h>
  15#include <sys/ioctl.h>
  16#include "qapi/error.h"
  17#include "hw/sysbus.h"
  18#include "hw/vfio/vfio.h"
  19#include "hw/vfio/vfio-common.h"
  20#include "hw/s390x/ap-device.h"
  21#include "qemu/error-report.h"
  22#include "qemu/queue.h"
  23#include "qemu/option.h"
  24#include "qemu/config-file.h"
  25#include "cpu.h"
  26#include "kvm_s390x.h"
  27#include "sysemu/sysemu.h"
  28#include "hw/s390x/ap-bridge.h"
  29#include "exec/address-spaces.h"
  30
  31#define VFIO_AP_DEVICE_TYPE      "vfio-ap"
  32
  33typedef struct VFIOAPDevice {
  34    APDevice apdev;
  35    VFIODevice vdev;
  36} VFIOAPDevice;
  37
  38#define VFIO_AP_DEVICE(obj) \
  39        OBJECT_CHECK(VFIOAPDevice, (obj), VFIO_AP_DEVICE_TYPE)
  40
  41static void vfio_ap_compute_needs_reset(VFIODevice *vdev)
  42{
  43    vdev->needs_reset = false;
  44}
  45
  46/*
  47 * We don't need vfio_hot_reset_multi and vfio_eoi operations for
  48 * vfio-ap device now.
  49 */
  50struct VFIODeviceOps vfio_ap_ops = {
  51    .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
  52};
  53
  54static void vfio_ap_put_device(VFIOAPDevice *vapdev)
  55{
  56    g_free(vapdev->vdev.name);
  57    vfio_put_base_device(&vapdev->vdev);
  58}
  59
  60static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)
  61{
  62    GError *gerror = NULL;
  63    char *symlink, *group_path;
  64    int groupid;
  65
  66    symlink = g_strdup_printf("%s/iommu_group", vapdev->vdev.sysfsdev);
  67    group_path = g_file_read_link(symlink, &gerror);
  68    g_free(symlink);
  69
  70    if (!group_path) {
  71        error_setg(errp, "%s: no iommu_group found for %s: %s",
  72                   VFIO_AP_DEVICE_TYPE, vapdev->vdev.sysfsdev, gerror->message);
  73        return NULL;
  74    }
  75
  76    if (sscanf(basename(group_path), "%d", &groupid) != 1) {
  77        error_setg(errp, "vfio: failed to read %s", group_path);
  78        g_free(group_path);
  79        return NULL;
  80    }
  81
  82    g_free(group_path);
  83
  84    return vfio_get_group(groupid, &address_space_memory, errp);
  85}
  86
  87static void vfio_ap_realize(DeviceState *dev, Error **errp)
  88{
  89    int ret;
  90    char *mdevid;
  91    Error *local_err = NULL;
  92    VFIOGroup *vfio_group;
  93    APDevice *apdev = AP_DEVICE(dev);
  94    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
  95
  96    vfio_group = vfio_ap_get_group(vapdev, &local_err);
  97    if (!vfio_group) {
  98        goto out_err;
  99    }
 100
 101    vapdev->vdev.ops = &vfio_ap_ops;
 102    vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;
 103    mdevid = basename(vapdev->vdev.sysfsdev);
 104    vapdev->vdev.name = g_strdup_printf("%s", mdevid);
 105    vapdev->vdev.dev = dev;
 106
 107    /*
 108     * vfio-ap devices operate in a way compatible with
 109     * memory ballooning, as no pages are pinned in the host.
 110     * This needs to be set before vfio_get_device() for vfio common to
 111     * handle the balloon inhibitor.
 112     */
 113    vapdev->vdev.balloon_allowed = true;
 114
 115    ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, &local_err);
 116    if (ret) {
 117        goto out_get_dev_err;
 118    }
 119
 120    return;
 121
 122out_get_dev_err:
 123    vfio_ap_put_device(vapdev);
 124    vfio_put_group(vfio_group);
 125out_err:
 126    error_propagate(errp, local_err);
 127}
 128
 129static void vfio_ap_unrealize(DeviceState *dev, Error **errp)
 130{
 131    APDevice *apdev = AP_DEVICE(dev);
 132    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 133    VFIOGroup *group = vapdev->vdev.group;
 134
 135    vfio_ap_put_device(vapdev);
 136    vfio_put_group(group);
 137}
 138
 139static Property vfio_ap_properties[] = {
 140    DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
 141    DEFINE_PROP_END_OF_LIST(),
 142};
 143
 144static void vfio_ap_reset(DeviceState *dev)
 145{
 146    int ret;
 147    APDevice *apdev = AP_DEVICE(dev);
 148    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 149
 150    ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
 151    if (ret) {
 152        error_report("%s: failed to reset %s device: %s", __func__,
 153                     vapdev->vdev.name, strerror(errno));
 154    }
 155}
 156
 157static const VMStateDescription vfio_ap_vmstate = {
 158    .name = VFIO_AP_DEVICE_TYPE,
 159    .unmigratable = 1,
 160};
 161
 162static void vfio_ap_class_init(ObjectClass *klass, void *data)
 163{
 164    DeviceClass *dc = DEVICE_CLASS(klass);
 165
 166    dc->props = vfio_ap_properties;
 167    dc->vmsd = &vfio_ap_vmstate;
 168    dc->desc = "VFIO-based AP device assignment";
 169    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 170    dc->realize = vfio_ap_realize;
 171    dc->unrealize = vfio_ap_unrealize;
 172    dc->hotpluggable = true;
 173    dc->reset = vfio_ap_reset;
 174    dc->bus_type = TYPE_AP_BUS;
 175}
 176
 177static const TypeInfo vfio_ap_info = {
 178    .name = VFIO_AP_DEVICE_TYPE,
 179    .parent = AP_DEVICE_TYPE,
 180    .instance_size = sizeof(VFIOAPDevice),
 181    .class_init = vfio_ap_class_init,
 182};
 183
 184static void vfio_ap_type_init(void)
 185{
 186    type_register_static(&vfio_ap_info);
 187}
 188
 189type_init(vfio_ap_type_init)
 190