sm501: Add missing arbitration control register
[qemu.git] / hw / scsi / virtio-scsi-dataplane.c
1 /*
2 * Virtio SCSI dataplane
3 *
4 * Copyright Red Hat, Inc. 2014
5 *
6 * Authors:
7 * Fam Zheng <famz@redhat.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
11 *
12 */
13
14 #include "qemu/osdep.h"
15 #include "qapi/error.h"
16 #include "hw/virtio/virtio-scsi.h"
17 #include "qemu/error-report.h"
18 #include "sysemu/block-backend.h"
19 #include "hw/scsi/scsi.h"
20 #include "block/scsi.h"
21 #include "hw/virtio/virtio-bus.h"
22 #include "hw/virtio/virtio-access.h"
23
24 /* Context: QEMU global mutex held */
25 void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp)
26 {
27 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
28 VirtIODevice *vdev = VIRTIO_DEVICE(s);
29 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
30 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
31
32 if (vs->conf.iothread) {
33 if (!k->set_guest_notifiers || !k->ioeventfd_assign) {
34 error_setg(errp,
35 "device is incompatible with iothread "
36 "(transport does not support notifiers)");
37 return;
38 }
39 if (!virtio_device_ioeventfd_enabled(vdev)) {
40 error_setg(errp, "ioeventfd is required for iothread");
41 return;
42 }
43 s->ctx = iothread_get_aio_context(vs->conf.iothread);
44 } else {
45 if (!virtio_device_ioeventfd_enabled(vdev)) {
46 return;
47 }
48 s->ctx = qemu_get_aio_context();
49 }
50 }
51
52 static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev,
53 VirtQueue *vq)
54 {
55 bool progress;
56 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
57
58 virtio_scsi_acquire(s);
59 assert(s->ctx && s->dataplane_started);
60 progress = virtio_scsi_handle_cmd_vq(s, vq);
61 virtio_scsi_release(s);
62 return progress;
63 }
64
65 static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev,
66 VirtQueue *vq)
67 {
68 bool progress;
69 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
70
71 virtio_scsi_acquire(s);
72 assert(s->ctx && s->dataplane_started);
73 progress = virtio_scsi_handle_ctrl_vq(s, vq);
74 virtio_scsi_release(s);
75 return progress;
76 }
77
78 static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev,
79 VirtQueue *vq)
80 {
81 bool progress;
82 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
83
84 virtio_scsi_acquire(s);
85 assert(s->ctx && s->dataplane_started);
86 progress = virtio_scsi_handle_event_vq(s, vq);
87 virtio_scsi_release(s);
88 return progress;
89 }
90
91 static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n,
92 VirtIOHandleAIOOutput fn)
93 {
94 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
95 int rc;
96
97 /* Set up virtqueue notify */
98 rc = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), n, true);
99 if (rc != 0) {
100 fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n",
101 rc);
102 s->dataplane_fenced = true;
103 return rc;
104 }
105
106 virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, fn);
107 return 0;
108 }
109
110 /* assumes s->ctx held */
111 static void virtio_scsi_clear_aio(VirtIOSCSI *s)
112 {
113 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
114 int i;
115
116 virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, NULL);
117 virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, NULL);
118 for (i = 0; i < vs->conf.num_queues; i++) {
119 virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, NULL);
120 }
121 }
122
123 /* Context: QEMU global mutex held */
124 int virtio_scsi_dataplane_start(VirtIODevice *vdev)
125 {
126 int i;
127 int rc;
128 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
129 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
130 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
131 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
132
133 if (s->dataplane_started ||
134 s->dataplane_starting ||
135 s->dataplane_fenced) {
136 return 0;
137 }
138
139 s->dataplane_starting = true;
140
141 /* Set up guest notifier (irq) */
142 rc = k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, true);
143 if (rc != 0) {
144 fprintf(stderr, "virtio-scsi: Failed to set guest notifiers (%d), "
145 "ensure -enable-kvm is set\n", rc);
146 goto fail_guest_notifiers;
147 }
148
149 aio_context_acquire(s->ctx);
150 rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0,
151 virtio_scsi_data_plane_handle_ctrl);
152 if (rc) {
153 goto fail_vrings;
154 }
155 rc = virtio_scsi_vring_init(s, vs->event_vq, 1,
156 virtio_scsi_data_plane_handle_event);
157 if (rc) {
158 goto fail_vrings;
159 }
160 for (i = 0; i < vs->conf.num_queues; i++) {
161 rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2,
162 virtio_scsi_data_plane_handle_cmd);
163 if (rc) {
164 goto fail_vrings;
165 }
166 }
167
168 s->dataplane_starting = false;
169 s->dataplane_started = true;
170 aio_context_release(s->ctx);
171 return 0;
172
173 fail_vrings:
174 virtio_scsi_clear_aio(s);
175 aio_context_release(s->ctx);
176 for (i = 0; i < vs->conf.num_queues + 2; i++) {
177 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
178 }
179 k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
180 fail_guest_notifiers:
181 s->dataplane_fenced = true;
182 s->dataplane_starting = false;
183 s->dataplane_started = true;
184 return -ENOSYS;
185 }
186
187 /* Context: QEMU global mutex held */
188 void virtio_scsi_dataplane_stop(VirtIODevice *vdev)
189 {
190 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
191 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
192 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
193 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
194 int i;
195
196 if (!s->dataplane_started || s->dataplane_stopping) {
197 return;
198 }
199
200 /* Better luck next time. */
201 if (s->dataplane_fenced) {
202 s->dataplane_fenced = false;
203 s->dataplane_started = false;
204 return;
205 }
206 s->dataplane_stopping = true;
207
208 aio_context_acquire(s->ctx);
209 virtio_scsi_clear_aio(s);
210 aio_context_release(s->ctx);
211
212 blk_drain_all(); /* ensure there are no in-flight requests */
213
214 for (i = 0; i < vs->conf.num_queues + 2; i++) {
215 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
216 }
217
218 /* Clean up guest notifier (irq) */
219 k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
220 s->dataplane_stopping = false;
221 s->dataplane_started = false;
222 }