xref: /openbmc/qemu/hw/vfio/ap.c (revision 22e3284f)
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/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 = true;
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)
190