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
  35 struct VFIOAPDevice {
  36     APDevice apdev;
  37     VFIODevice vdev;
  38 };
  39 typedef struct VFIOAPDevice VFIOAPDevice;
  40
  41 DECLARE_INSTANCE_CHECKER(VFIOAPDevice, VFIO_AP_DEVICE,
  42                          TYPE_VFIO_AP_DEVICE)
  43
  44 static void vfio_ap_compute_needs_reset(VFIODevice *vdev)
  45 {
  46     vdev->needs_reset = false;
  47 }
  48
  49 /*
  50  * We don't need vfio_hot_reset_multi and vfio_eoi operations for
  51  * vfio-ap device now.
  52  */
  53 struct VFIODeviceOps vfio_ap_ops = {
  54     .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
  55 };
  56
  57 static void vfio_ap_put_device(VFIOAPDevice *vapdev)
  58 {
  59     g_free(vapdev->vdev.name);
  60     vfio_put_base_device(&vapdev->vdev);
  61 }
  62
  63 static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)
  64 {
  65     GError *gerror = NULL;
  66     char *symlink, *group_path;
  67     int groupid;
  68
  69     symlink = g_strdup_printf("%s/iommu_group", vapdev->vdev.sysfsdev);
  70     group_path = g_file_read_link(symlink, &gerror);
  71     g_free(symlink);
  72
  73     if (!group_path) {
  74         error_setg(errp, "%s: no iommu_group found for %s: %s",
  75                    TYPE_VFIO_AP_DEVICE, vapdev->vdev.sysfsdev, gerror->message);
  76         g_error_free(gerror);
  77         return NULL;
  78     }
  79
  80     if (sscanf(basename(group_path), "%d", &groupid) != 1) {
  81         error_setg(errp, "vfio: failed to read %s", group_path);
  82         g_free(group_path);
  83         return NULL;
  84     }
  85
  86     g_free(group_path);
  87
  88     return vfio_get_group(groupid, &address_space_memory, errp);
  89 }
  90
  91 static void vfio_ap_realize(DeviceState *dev, Error **errp)
  92 {
  93     int ret;
  94     char *mdevid;
  95     VFIOGroup *vfio_group;
  96     APDevice *apdev = AP_DEVICE(dev);
  97     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
  98
  99     vfio_group = vfio_ap_get_group(vapdev, errp);
 100     if (!vfio_group) {
 101         return;
 102     }
 103
 104     vapdev->vdev.ops = &vfio_ap_ops;
 105     vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;
 106     mdevid = basename(vapdev->vdev.sysfsdev);
 107     vapdev->vdev.name = g_strdup_printf("%s", mdevid);
 108     vapdev->vdev.dev = dev;
 109
 110     /*
 111      * vfio-ap devices operate in a way compatible with discarding of
 112      * memory in RAM blocks, as no pages are pinned in the host.
 113      * This needs to be set before vfio_get_device() for vfio common to
 114      * handle ram_block_discard_disable().
 115      */
 116     vapdev->vdev.ram_block_discard_allowed = true;
 117
 118     ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, errp);
 119     if (ret) {
 120         goto out_get_dev_err;
 121     }
 122
 123     return;
 124
 125 out_get_dev_err:
 126     vfio_ap_put_device(vapdev);
 127     vfio_put_group(vfio_group);
 128 }
 129
 130 static void vfio_ap_unrealize(DeviceState *dev)
 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
 140 static Property vfio_ap_properties[] = {
 141     DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
 142     DEFINE_PROP_END_OF_LIST(),
 143 };
 144
 145 static 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
 158 static const VMStateDescription vfio_ap_vmstate = {
 159     .name = "vfio-ap",
 160     .unmigratable = 1,
 161 };
 162
 163 static void vfio_ap_class_init(ObjectClass *klass, void *data)
 164 {
 165     DeviceClass *dc = DEVICE_CLASS(klass);
 166
 167     device_class_set_props(dc, 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
 178 static const TypeInfo vfio_ap_info = {
 179     .name = TYPE_VFIO_AP_DEVICE,
 180     .parent = TYPE_AP_DEVICE,
 181     .instance_size = sizeof(VFIOAPDevice),
 182     .class_init = vfio_ap_class_init,
 183 };
 184
 185 static void vfio_ap_type_init(void)
 186 {
 187     type_register_static(&vfio_ap_info);
 188 }
 189
 190 type_init(vfio_ap_type_init)