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
  32 #define VFIO_AP_DEVICE_TYPE      "vfio-ap"
  33
  34 typedef 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
  42 static 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  */
  51 struct VFIODeviceOps vfio_ap_ops = {
  52     .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
  53 };
  54
  55 static void vfio_ap_put_device(VFIOAPDevice *vapdev)
  56 {
  57     g_free(vapdev->vdev.name);
  58     vfio_put_base_device(&vapdev->vdev);
  59 }
  60
  61 static 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         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
  89 static 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
 123 out_get_dev_err:
 124     vfio_ap_put_device(vapdev);
 125     vfio_put_group(vfio_group);
 126 }
 127
 128 static 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
 138 static Property vfio_ap_properties[] = {
 139     DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
 140     DEFINE_PROP_END_OF_LIST(),
 141 };
 142
 143 static 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
 156 static const VMStateDescription vfio_ap_vmstate = {
 157     .name = "vfio-ap",
 158     .unmigratable = 1,
 159 };
 160
 161 static 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
 176 static const TypeInfo vfio_ap_info = {
 177     .name = VFIO_AP_DEVICE_TYPE,
 178     .parent = AP_DEVICE_TYPE,
 179     .instance_size = sizeof(VFIOAPDevice),
 180     .class_init = vfio_ap_class_init,
 181 };
 182
 183 static void vfio_ap_type_init(void)
 184 {
 185     type_register_static(&vfio_ap_info);
 186 }
 187
 188 type_init(vfio_ap_type_init)