xref: /openbmc/qemu/hw/vfio/ap.c (revision 650d103d)
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/queue.h"
24 #include "qemu/option.h"
25 #include "qemu/config-file.h"
26 #include "cpu.h"
27 #include "kvm_s390x.h"
28 #include "migration/vmstate.h"
29 #include "sysemu/sysemu.h"
30 #include "hw/s390x/ap-bridge.h"
31 #include "exec/address-spaces.h"
32 
33 #define VFIO_AP_DEVICE_TYPE      "vfio-ap"
34 
35 typedef struct VFIOAPDevice {
36     APDevice apdev;
37     VFIODevice vdev;
38 } VFIOAPDevice;
39 
40 #define VFIO_AP_DEVICE(obj) \
41         OBJECT_CHECK(VFIOAPDevice, (obj), VFIO_AP_DEVICE_TYPE)
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                    VFIO_AP_DEVICE_TYPE, vapdev->vdev.sysfsdev, gerror->message);
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     Error *local_err = NULL;
94     VFIOGroup *vfio_group;
95     APDevice *apdev = AP_DEVICE(dev);
96     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
97 
98     vfio_group = vfio_ap_get_group(vapdev, &local_err);
99     if (!vfio_group) {
100         goto out_err;
101     }
102 
103     vapdev->vdev.ops = &vfio_ap_ops;
104     vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;
105     mdevid = basename(vapdev->vdev.sysfsdev);
106     vapdev->vdev.name = g_strdup_printf("%s", mdevid);
107     vapdev->vdev.dev = dev;
108 
109     /*
110      * vfio-ap devices operate in a way compatible with
111      * memory ballooning, as no pages are pinned in the host.
112      * This needs to be set before vfio_get_device() for vfio common to
113      * handle the balloon inhibitor.
114      */
115     vapdev->vdev.balloon_allowed = true;
116 
117     ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, &local_err);
118     if (ret) {
119         goto out_get_dev_err;
120     }
121 
122     return;
123 
124 out_get_dev_err:
125     vfio_ap_put_device(vapdev);
126     vfio_put_group(vfio_group);
127 out_err:
128     error_propagate(errp, local_err);
129 }
130 
131 static void vfio_ap_unrealize(DeviceState *dev, Error **errp)
132 {
133     APDevice *apdev = AP_DEVICE(dev);
134     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
135     VFIOGroup *group = vapdev->vdev.group;
136 
137     vfio_ap_put_device(vapdev);
138     vfio_put_group(group);
139 }
140 
141 static Property vfio_ap_properties[] = {
142     DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
143     DEFINE_PROP_END_OF_LIST(),
144 };
145 
146 static void vfio_ap_reset(DeviceState *dev)
147 {
148     int ret;
149     APDevice *apdev = AP_DEVICE(dev);
150     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
151 
152     ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
153     if (ret) {
154         error_report("%s: failed to reset %s device: %s", __func__,
155                      vapdev->vdev.name, strerror(errno));
156     }
157 }
158 
159 static const VMStateDescription vfio_ap_vmstate = {
160     .name = "vfio-ap",
161     .unmigratable = 1,
162 };
163 
164 static void vfio_ap_class_init(ObjectClass *klass, void *data)
165 {
166     DeviceClass *dc = DEVICE_CLASS(klass);
167 
168     dc->props = vfio_ap_properties;
169     dc->vmsd = &vfio_ap_vmstate;
170     dc->desc = "VFIO-based AP device assignment";
171     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
172     dc->realize = vfio_ap_realize;
173     dc->unrealize = vfio_ap_unrealize;
174     dc->hotpluggable = true;
175     dc->reset = vfio_ap_reset;
176     dc->bus_type = TYPE_AP_BUS;
177 }
178 
179 static const TypeInfo vfio_ap_info = {
180     .name = VFIO_AP_DEVICE_TYPE,
181     .parent = AP_DEVICE_TYPE,
182     .instance_size = sizeof(VFIOAPDevice),
183     .class_init = vfio_ap_class_init,
184 };
185 
186 static void vfio_ap_type_init(void)
187 {
188     type_register_static(&vfio_ap_info);
189 }
190 
191 type_init(vfio_ap_type_init)
192