xref: /openbmc/qemu/hw/vfio/ap.c (revision 3cad405b)
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         return NULL;
75     }
76 
77     if (sscanf(basename(group_path), "%d", &groupid) != 1) {
78         error_setg(errp, "vfio: failed to read %s", group_path);
79         g_free(group_path);
80         return NULL;
81     }
82 
83     g_free(group_path);
84 
85     return vfio_get_group(groupid, &address_space_memory, errp);
86 }
87 
88 static void vfio_ap_realize(DeviceState *dev, Error **errp)
89 {
90     int ret;
91     char *mdevid;
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, errp);
97     if (!vfio_group) {
98         return;
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, errp);
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 }
126 
127 static void vfio_ap_unrealize(DeviceState *dev, Error **errp)
128 {
129     APDevice *apdev = AP_DEVICE(dev);
130     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
131     VFIOGroup *group = vapdev->vdev.group;
132 
133     vfio_ap_put_device(vapdev);
134     vfio_put_group(group);
135 }
136 
137 static Property vfio_ap_properties[] = {
138     DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
139     DEFINE_PROP_END_OF_LIST(),
140 };
141 
142 static void vfio_ap_reset(DeviceState *dev)
143 {
144     int ret;
145     APDevice *apdev = AP_DEVICE(dev);
146     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
147 
148     ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
149     if (ret) {
150         error_report("%s: failed to reset %s device: %s", __func__,
151                      vapdev->vdev.name, strerror(errno));
152     }
153 }
154 
155 static const VMStateDescription vfio_ap_vmstate = {
156     .name = "vfio-ap",
157     .unmigratable = 1,
158 };
159 
160 static void vfio_ap_class_init(ObjectClass *klass, void *data)
161 {
162     DeviceClass *dc = DEVICE_CLASS(klass);
163 
164     dc->props = vfio_ap_properties;
165     dc->vmsd = &vfio_ap_vmstate;
166     dc->desc = "VFIO-based AP device assignment";
167     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
168     dc->realize = vfio_ap_realize;
169     dc->unrealize = vfio_ap_unrealize;
170     dc->hotpluggable = true;
171     dc->reset = vfio_ap_reset;
172     dc->bus_type = TYPE_AP_BUS;
173 }
174 
175 static const TypeInfo vfio_ap_info = {
176     .name = VFIO_AP_DEVICE_TYPE,
177     .parent = AP_DEVICE_TYPE,
178     .instance_size = sizeof(VFIOAPDevice),
179     .class_init = vfio_ap_class_init,
180 };
181 
182 static void vfio_ap_type_init(void)
183 {
184     type_register_static(&vfio_ap_info);
185 }
186 
187 type_init(vfio_ap_type_init)
188