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/option.h"
  24#include "qemu/config-file.h"
  25#include "cpu.h"
  26#include "kvm_s390x.h"
  27#include "migration/vmstate.h"
  28#include "hw/qdev-properties.h"
  29#include "hw/s390x/ap-bridge.h"
  30#include "exec/address-spaces.h"
  31#include "qom/object.h"
  32
  33#define TYPE_VFIO_AP_DEVICE      "vfio-ap"
  34
  35struct VFIOAPDevice {
  36    APDevice apdev;
  37    VFIODevice vdev;
  38};
  39
  40OBJECT_DECLARE_SIMPLE_TYPE(VFIOAPDevice, VFIO_AP_DEVICE)
  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                   TYPE_VFIO_AP_DEVICE, vapdev->vdev.sysfsdev, gerror->message);
  74        g_error_free(gerror);
  75        return NULL;
  76    }
  77
  78    if (sscanf(basename(group_path), "%d", &groupid) != 1) {
  79        error_setg(errp, "vfio: failed to read %s", group_path);
  80        g_free(group_path);
  81        return NULL;
  82    }
  83
  84    g_free(group_path);
  85
  86    return vfio_get_group(groupid, &address_space_memory, errp);
  87}
  88
  89static void vfio_ap_realize(DeviceState *dev, Error **errp)
  90{
  91    int ret;
  92    char *mdevid;
  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, errp);
  98    if (!vfio_group) {
  99        return;
 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 discarding of
 110     * memory in RAM blocks, as no pages are pinned in the host.
 111     * This needs to be set before vfio_get_device() for vfio common to
 112     * handle ram_block_discard_disable().
 113     */
 114    vapdev->vdev.ram_block_discard_allowed = true;
 115
 116    ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, errp);
 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);
 126}
 127
 128static void vfio_ap_unrealize(DeviceState *dev)
 129{
 130    APDevice *apdev = AP_DEVICE(dev);
 131    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 132    VFIOGroup *group = vapdev->vdev.group;
 133
 134    vfio_ap_put_device(vapdev);
 135    vfio_put_group(group);
 136}
 137
 138static Property vfio_ap_properties[] = {
 139    DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
 140    DEFINE_PROP_END_OF_LIST(),
 141};
 142
 143static void vfio_ap_reset(DeviceState *dev)
 144{
 145    int ret;
 146    APDevice *apdev = AP_DEVICE(dev);
 147    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 148
 149    ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
 150    if (ret) {
 151        error_report("%s: failed to reset %s device: %s", __func__,
 152                     vapdev->vdev.name, strerror(errno));
 153    }
 154}
 155
 156static const VMStateDescription vfio_ap_vmstate = {
 157    .name = "vfio-ap",
 158    .unmigratable = 1,
 159};
 160
 161static void vfio_ap_class_init(ObjectClass *klass, void *data)
 162{
 163    DeviceClass *dc = DEVICE_CLASS(klass);
 164
 165    device_class_set_props(dc, vfio_ap_properties);
 166    dc->vmsd = &vfio_ap_vmstate;
 167    dc->desc = "VFIO-based AP device assignment";
 168    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 169    dc->realize = vfio_ap_realize;
 170    dc->unrealize = vfio_ap_unrealize;
 171    dc->hotpluggable = true;
 172    dc->reset = vfio_ap_reset;
 173    dc->bus_type = TYPE_AP_BUS;
 174}
 175
 176static const TypeInfo vfio_ap_info = {
 177    .name = TYPE_VFIO_AP_DEVICE,
 178    .parent = TYPE_AP_DEVICE,
 179    .instance_size = sizeof(VFIOAPDevice),
 180    .class_init = vfio_ap_class_init,
 181};
 182
 183static void vfio_ap_type_init(void)
 184{
 185    type_register_static(&vfio_ap_info);
 186}
 187
 188type_init(vfio_ap_type_init)
 189