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/vfio/vfio.h"
  18 #include "hw/vfio/vfio-common.h"
  19 #include "hw/s390x/ap-device.h"
  20 #include "qemu/error-report.h"
  21 #include "qemu/event_notifier.h"
  22 #include "qemu/main-loop.h"
  23 #include "qemu/module.h"
  24 #include "qemu/option.h"
  25 #include "qemu/config-file.h"
  26 #include "kvm/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     EventNotifier req_notifier;
  39 };
  40
  41 OBJECT_DECLARE_SIMPLE_TYPE(VFIOAPDevice, VFIO_AP_DEVICE)
  42
  43 static void vfio_ap_compute_needs_reset(VFIODevice *vdev)
  44 {
  45     vdev->needs_reset = false;
  46 }
  47
  48 /*
  49  * We don't need vfio_hot_reset_multi and vfio_eoi operations for
  50  * vfio-ap device now.
  51  */
  52 struct VFIODeviceOps vfio_ap_ops = {
  53     .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
  54 };
  55
  56 static void vfio_ap_put_device(VFIOAPDevice *vapdev)
  57 {
  58     g_free(vapdev->vdev.name);
  59     vfio_put_base_device(&vapdev->vdev);
  60 }
  61
  62 static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)
  63 {
  64     GError *gerror = NULL;
  65     char *symlink, *group_path;
  66     int groupid;
  67
  68     symlink = g_strdup_printf("%s/iommu_group", vapdev->vdev.sysfsdev);
  69     group_path = g_file_read_link(symlink, &gerror);
  70     g_free(symlink);
  71
  72     if (!group_path) {
  73         error_setg(errp, "%s: no iommu_group found for %s: %s",
  74                    TYPE_VFIO_AP_DEVICE, vapdev->vdev.sysfsdev, gerror->message);
  75         g_error_free(gerror);
  76         return NULL;
  77     }
  78
  79     if (sscanf(basename(group_path), "%d", &groupid) != 1) {
  80         error_setg(errp, "vfio: failed to read %s", group_path);
  81         g_free(group_path);
  82         return NULL;
  83     }
  84
  85     g_free(group_path);
  86
  87     return vfio_get_group(groupid, &address_space_memory, errp);
  88 }
  89
  90 static void vfio_ap_req_notifier_handler(void *opaque)
  91 {
  92     VFIOAPDevice *vapdev = opaque;
  93     Error *err = NULL;
  94
  95     if (!event_notifier_test_and_clear(&vapdev->req_notifier)) {
  96         return;
  97     }
  98
  99     qdev_unplug(DEVICE(vapdev), &err);
 100
 101     if (err) {
 102         warn_reportf_err(err, VFIO_MSG_PREFIX, vapdev->vdev.name);
 103     }
 104 }
 105
 106 static void vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
 107                                           unsigned int irq, Error **errp)
 108 {
 109     int fd;
 110     size_t argsz;
 111     IOHandler *fd_read;
 112     EventNotifier *notifier;
 113     struct vfio_irq_info *irq_info;
 114     VFIODevice *vdev = &vapdev->vdev;
 115
 116     switch (irq) {
 117     case VFIO_AP_REQ_IRQ_INDEX:
 118         notifier = &vapdev->req_notifier;
 119         fd_read = vfio_ap_req_notifier_handler;
 120         break;
 121     default:
 122         error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
 123         return;
 124     }
 125
 126     if (vdev->num_irqs < irq + 1) {
 127         error_setg(errp, "vfio: IRQ %u not available (number of irqs %u)",
 128                    irq, vdev->num_irqs);
 129         return;
 130     }
 131
 132     argsz = sizeof(*irq_info);
 133     irq_info = g_malloc0(argsz);
 134     irq_info->index = irq;
 135     irq_info->argsz = argsz;
 136
 137     if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
 138               irq_info) < 0 || irq_info->count < 1) {
 139         error_setg_errno(errp, errno, "vfio: Error getting irq info");
 140         goto out_free_info;
 141     }
 142
 143     if (event_notifier_init(notifier, 0)) {
 144         error_setg_errno(errp, errno,
 145                          "vfio: Unable to init event notifier for irq (%d)",
 146                          irq);
 147         goto out_free_info;
 148     }
 149
 150     fd = event_notifier_get_fd(notifier);
 151     qemu_set_fd_handler(fd, fd_read, NULL, vapdev);
 152
 153     if (vfio_set_irq_signaling(vdev, irq, 0, VFIO_IRQ_SET_ACTION_TRIGGER, fd,
 154                                errp)) {
 155         qemu_set_fd_handler(fd, NULL, NULL, vapdev);
 156         event_notifier_cleanup(notifier);
 157     }
 158
 159 out_free_info:
 160     g_free(irq_info);
 161
 162 }
 163
 164 static void vfio_ap_unregister_irq_notifier(VFIOAPDevice *vapdev,
 165                                             unsigned int irq)
 166 {
 167     Error *err = NULL;
 168     EventNotifier *notifier;
 169
 170     switch (irq) {
 171     case VFIO_AP_REQ_IRQ_INDEX:
 172         notifier = &vapdev->req_notifier;
 173         break;
 174     default:
 175         error_report("vfio: Unsupported device irq(%d)", irq);
 176         return;
 177     }
 178
 179     if (vfio_set_irq_signaling(&vapdev->vdev, irq, 0,
 180                                VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
 181         warn_reportf_err(err, VFIO_MSG_PREFIX, vapdev->vdev.name);
 182     }
 183
 184     qemu_set_fd_handler(event_notifier_get_fd(notifier),
 185                         NULL, NULL, vapdev);
 186     event_notifier_cleanup(notifier);
 187 }
 188
 189 static void vfio_ap_realize(DeviceState *dev, Error **errp)
 190 {
 191     int ret;
 192     char *mdevid;
 193     Error *err = NULL;
 194     VFIOGroup *vfio_group;
 195     APDevice *apdev = AP_DEVICE(dev);
 196     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 197
 198     vfio_group = vfio_ap_get_group(vapdev, errp);
 199     if (!vfio_group) {
 200         return;
 201     }
 202
 203     vapdev->vdev.ops = &vfio_ap_ops;
 204     vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;
 205     mdevid = basename(vapdev->vdev.sysfsdev);
 206     vapdev->vdev.name = g_strdup_printf("%s", mdevid);
 207     vapdev->vdev.dev = dev;
 208
 209     /*
 210      * vfio-ap devices operate in a way compatible with discarding of
 211      * memory in RAM blocks, as no pages are pinned in the host.
 212      * This needs to be set before vfio_get_device() for vfio common to
 213      * handle ram_block_discard_disable().
 214      */
 215     vapdev->vdev.ram_block_discard_allowed = true;
 216
 217     ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, errp);
 218     if (ret) {
 219         goto out_get_dev_err;
 220     }
 221
 222     vfio_ap_register_irq_notifier(vapdev, VFIO_AP_REQ_IRQ_INDEX, &err);
 223     if (err) {
 224         /*
 225          * Report this error, but do not make it a failing condition.
 226          * Lack of this IRQ in the host does not prevent normal operation.
 227          */
 228         error_report_err(err);
 229     }
 230
 231     return;
 232
 233 out_get_dev_err:
 234     vfio_ap_put_device(vapdev);
 235     vfio_put_group(vfio_group);
 236 }
 237
 238 static void vfio_ap_unrealize(DeviceState *dev)
 239 {
 240     APDevice *apdev = AP_DEVICE(dev);
 241     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 242     VFIOGroup *group = vapdev->vdev.group;
 243
 244     vfio_ap_unregister_irq_notifier(vapdev, VFIO_AP_REQ_IRQ_INDEX);
 245     vfio_ap_put_device(vapdev);
 246     vfio_put_group(group);
 247 }
 248
 249 static Property vfio_ap_properties[] = {
 250     DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
 251     DEFINE_PROP_END_OF_LIST(),
 252 };
 253
 254 static void vfio_ap_reset(DeviceState *dev)
 255 {
 256     int ret;
 257     APDevice *apdev = AP_DEVICE(dev);
 258     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 259
 260     ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
 261     if (ret) {
 262         error_report("%s: failed to reset %s device: %s", __func__,
 263                      vapdev->vdev.name, strerror(errno));
 264     }
 265 }
 266
 267 static const VMStateDescription vfio_ap_vmstate = {
 268     .name = "vfio-ap",
 269     .unmigratable = 1,
 270 };
 271
 272 static void vfio_ap_class_init(ObjectClass *klass, void *data)
 273 {
 274     DeviceClass *dc = DEVICE_CLASS(klass);
 275
 276     device_class_set_props(dc, vfio_ap_properties);
 277     dc->vmsd = &vfio_ap_vmstate;
 278     dc->desc = "VFIO-based AP device assignment";
 279     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 280     dc->realize = vfio_ap_realize;
 281     dc->unrealize = vfio_ap_unrealize;
 282     dc->hotpluggable = true;
 283     dc->reset = vfio_ap_reset;
 284     dc->bus_type = TYPE_AP_BUS;
 285 }
 286
 287 static const TypeInfo vfio_ap_info = {
 288     .name = TYPE_VFIO_AP_DEVICE,
 289     .parent = TYPE_AP_DEVICE,
 290     .instance_size = sizeof(VFIOAPDevice),
 291     .class_init = vfio_ap_class_init,
 292 };
 293
 294 static void vfio_ap_type_init(void)
 295 {
 296     type_register_static(&vfio_ap_info);
 297 }
 298
 299 type_init(vfio_ap_type_init)