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