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 <linux/vfio.h>
  14 #include <sys/ioctl.h>
  15 #include "qemu/osdep.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/queue.h"
  23 #include "qemu/option.h"
  24 #include "qemu/config-file.h"
  25 #include "cpu.h"
  26 #include "kvm_s390x.h"
  27 #include "sysemu/sysemu.h"
  28 #include "hw/s390x/ap-bridge.h"
  29 #include "exec/address-spaces.h"
  30
  31 #define VFIO_AP_DEVICE_TYPE      "vfio-ap"
  32
  33 typedef struct VFIOAPDevice {
  34     APDevice apdev;
  35     VFIODevice vdev;
  36 } VFIOAPDevice;
  37
  38 #define VFIO_AP_DEVICE(obj) \
  39         OBJECT_CHECK(VFIOAPDevice, (obj), VFIO_AP_DEVICE_TYPE)
  40
  41 static void vfio_ap_compute_needs_reset(VFIODevice *vdev)
  42 {
  43     vdev->needs_reset = false;
  44 }
  45
  46 /*
  47  * We don't need vfio_hot_reset_multi and vfio_eoi operations for
  48  * vfio-ap device now.
  49  */
  50 struct VFIODeviceOps vfio_ap_ops = {
  51     .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
  52 };
  53
  54 static void vfio_ap_put_device(VFIOAPDevice *vapdev)
  55 {
  56     g_free(vapdev->vdev.name);
  57     vfio_put_base_device(&vapdev->vdev);
  58 }
  59
  60 static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)
  61 {
  62     GError *gerror = NULL;
  63     char *symlink, *group_path;
  64     int groupid;
  65
  66     symlink = g_strdup_printf("%s/iommu_group", vapdev->vdev.sysfsdev);
  67     group_path = g_file_read_link(symlink, &gerror);
  68     g_free(symlink);
  69
  70     if (!group_path) {
  71         error_setg(errp, "%s: no iommu_group found for %s: %s",
  72                    VFIO_AP_DEVICE_TYPE, vapdev->vdev.sysfsdev, gerror->message);
  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     Error *local_err = NULL;
  92     VFIOGroup *vfio_group;
  93     APDevice *apdev = AP_DEVICE(dev);
  94     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
  95
  96     vfio_group = vfio_ap_get_group(vapdev, &local_err);
  97     if (!vfio_group) {
  98         goto out_err;
  99     }
 100
 101     vapdev->vdev.ops = &vfio_ap_ops;
 102     vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;
 103     mdevid = basename(vapdev->vdev.sysfsdev);
 104     vapdev->vdev.name = g_strdup_printf("%s", mdevid);
 105     vapdev->vdev.dev = dev;
 106
 107     /*
 108      * vfio-ap devices operate in a way compatible with
 109      * memory ballooning, as no pages are pinned in the host.
 110      * This needs to be set before vfio_get_device() for vfio common to
 111      * handle the balloon inhibitor.
 112      */
 113     vapdev->vdev.balloon_allowed = true;
 114
 115     ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, &local_err);
 116     if (ret) {
 117         goto out_get_dev_err;
 118     }
 119
 120     return;
 121
 122 out_get_dev_err:
 123     vfio_ap_put_device(vapdev);
 124     vfio_put_group(vfio_group);
 125 out_err:
 126     error_propagate(errp, local_err);
 127 }
 128
 129 static void vfio_ap_unrealize(DeviceState *dev, Error **errp)
 130 {
 131     APDevice *apdev = AP_DEVICE(dev);
 132     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 133     VFIOGroup *group = vapdev->vdev.group;
 134
 135     vfio_ap_put_device(vapdev);
 136     vfio_put_group(group);
 137 }
 138
 139 static Property vfio_ap_properties[] = {
 140     DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
 141     DEFINE_PROP_END_OF_LIST(),
 142 };
 143
 144 static void vfio_ap_reset(DeviceState *dev)
 145 {
 146     int ret;
 147     APDevice *apdev = AP_DEVICE(dev);
 148     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
 149
 150     ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
 151     if (ret) {
 152         error_report("%s: failed to reset %s device: %s", __func__,
 153                      vapdev->vdev.name, strerror(errno));
 154     }
 155 }
 156
 157 static const VMStateDescription vfio_ap_vmstate = {
 158     .name = VFIO_AP_DEVICE_TYPE,
 159     .unmigratable = 1,
 160 };
 161
 162 static void vfio_ap_class_init(ObjectClass *klass, void *data)
 163 {
 164     DeviceClass *dc = DEVICE_CLASS(klass);
 165
 166     dc->props = vfio_ap_properties;
 167     dc->vmsd = &vfio_ap_vmstate;
 168     dc->desc = "VFIO-based AP device assignment";
 169     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 170     dc->realize = vfio_ap_realize;
 171     dc->unrealize = vfio_ap_unrealize;
 172     dc->hotpluggable = false;
 173     dc->reset = vfio_ap_reset;
 174     dc->bus_type = TYPE_AP_BUS;
 175 }
 176
 177 static const TypeInfo vfio_ap_info = {
 178     .name = VFIO_AP_DEVICE_TYPE,
 179     .parent = AP_DEVICE_TYPE,
 180     .instance_size = sizeof(VFIOAPDevice),
 181     .class_init = vfio_ap_class_init,
 182 };
 183
 184 static void vfio_ap_type_init(void)
 185 {
 186     type_register_static(&vfio_ap_info);
 187 }
 188
 189 type_init(vfio_ap_type_init)