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/module.h"
  23#include "qemu/queue.h"
  24#include "qemu/option.h"
  25#include "qemu/config-file.h"
  26#include "cpu.h"
  27#include "kvm_s390x.h"
  28#include "sysemu/sysemu.h"
  29#include "hw/s390x/ap-bridge.h"
  30#include "exec/address-spaces.h"
  31
  32#define VFIO_AP_DEVICE_TYPE      "vfio-ap"
  33
  34typedef struct VFIOAPDevice {
  35    APDevice apdev;
  36    VFIODevice vdev;
  37} VFIOAPDevice;
  38
  39#define VFIO_AP_DEVICE(obj) \
  40        OBJECT_CHECK(VFIOAPDevice, (obj), VFIO_AP_DEVICE_TYPE)
  41
  42static void vfio_ap_compute_needs_reset(VFIODevice *vdev)
  43{
  44    vdev->needs_reset = false;
  45}
  46
  47/*
  48 * We don't need vfio_hot_reset_multi and vfio_eoi operations for
  49 * vfio-ap device now.
  50 */
  51struct VFIODeviceOps vfio_ap_ops = {
  52    .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
  53};
  54
  55static void vfio_ap_put_device(VFIOAPDevice *vapdev)
  56{
  57    g_free(vapdev->vdev.name);
  58    vfio_put_base_device(&vapdev->vdev);
  59}
  60
  61static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)
  62{
  63    GError *gerror = NULL;
  64    char *symlink, *group_path;
  65    int groupid;
  66
  67    symlink = g_strdup_printf("%s/iommu_group", vapdev->vdev.sysfsdev);
  68    group_path = g_file_read_link(symlink, &gerror);
  69    g_free(symlink);
  70
  71    if (!group_path) {
  72        error_setg(errp, "%s: no iommu_group found for %s: %s",
  73                   VFIO_AP_DEVICE_TYPE, vapdev->vdev.sysfsdev, gerror->message);
  74        return NULL;
  75    }
  76
  77    if (sscanf(basename(group_path), "%d", &groupid) != 1) {
  78        error_setg(errp, "vfio: failed to read %s", group_path);
  79        g_free(group_path);
  80        return NULL;
  81    }
  82
  83    g_free(group_path);
  84
  85    return vfio_get_group(groupid, &address_space_memory, errp);
  86}
  87
  88static void vfio_ap_realize(DeviceState *dev, Error **errp)
  89{
  90    int ret;
  91    char *mdevid;
  92    Error *local_err = NULL;
  93    VFIOGroup *vfio_group;
  94    APDevice *apdev = AP_DEVICE(dev);
  95    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
  96
  97    vfio_group = vfio_ap_get_group(vapdev, &local_err);
  98    if (!vfio_group) {
  99        goto out_err;
 100    }
 101
 102    vapdev->vdev.ops = &vfio_ap_ops;
 103    vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;
 104    mdevid = basename(vapdev->vdev.sysfsdev);
 105    vapdev->vdev.name = g_strdup_printf("%s", mdevid);
 106    vapdev->vdev.dev = dev;
 107
 108    /*
 109     * vfio-ap devices operate in a way compatible with
 110     * memory ballooning, as no pages are pinned in the host.
 111     * This needs to be set before vfio_get_device() for vfio common to
 112     * handle the balloon inhibitor.
 113     */
 114    vapdev->vdev.balloon_allowed = true;
 115
 116    ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, &local_err);
 117    if (ret) {
 118        goto out_get_dev_err;
 119    }
 120
 121    return;
 122
 123out_get_dev_err:
 124    vfio_ap_put_device(vapdev);
 125    vfio_put_group(vfio_group);
 126out_err:
 127    error_propagate(errp, local_err);
 128}
 129
 130static void vfio_ap_unrealize(DeviceState *dev, Error **errp)
 131{
 132    APDevice *apdev = AP_DEVICE(dev);
 133    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 134    VFIOGroup *group = vapdev->vdev.group;
 135
 136    vfio_ap_put_device(vapdev);
 137    vfio_put_group(group);
 138}
 139
 140static Property vfio_ap_properties[] = {
 141    DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
 142    DEFINE_PROP_END_OF_LIST(),
 143};
 144
 145static void vfio_ap_reset(DeviceState *dev)
 146{
 147    int ret;
 148    APDevice *apdev = AP_DEVICE(dev);
 149    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 150
 151    ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
 152    if (ret) {
 153        error_report("%s: failed to reset %s device: %s", __func__,
 154                     vapdev->vdev.name, strerror(errno));
 155    }
 156}
 157
 158static const VMStateDescription vfio_ap_vmstate = {
 159    .name = "vfio-ap",
 160    .unmigratable = 1,
 161};
 162
 163static void vfio_ap_class_init(ObjectClass *klass, void *data)
 164{
 165    DeviceClass *dc = DEVICE_CLASS(klass);
 166
 167    dc->props = vfio_ap_properties;
 168    dc->vmsd = &vfio_ap_vmstate;
 169    dc->desc = "VFIO-based AP device assignment";
 170    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 171    dc->realize = vfio_ap_realize;
 172    dc->unrealize = vfio_ap_unrealize;
 173    dc->hotpluggable = true;
 174    dc->reset = vfio_ap_reset;
 175    dc->bus_type = TYPE_AP_BUS;
 176}
 177
 178static const TypeInfo vfio_ap_info = {
 179    .name = VFIO_AP_DEVICE_TYPE,
 180    .parent = AP_DEVICE_TYPE,
 181    .instance_size = sizeof(VFIOAPDevice),
 182    .class_init = vfio_ap_class_init,
 183};
 184
 185static void vfio_ap_type_init(void)
 186{
 187    type_register_static(&vfio_ap_info);
 188}
 189
 190type_init(vfio_ap_type_init)
 191