meson: convert qapi-specific to meson
[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 "scsi/constants.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 /* Context: BH in IOThread */
111 static void virtio_scsi_dataplane_stop_bh(void *opaque)
112 {
113 VirtIOSCSI *s = opaque;
114 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
115 int i;
116
117 virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, NULL);
118 virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, NULL);
119 for (i = 0; i < vs->conf.num_queues; i++) {
120 virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, NULL);
121 }
122 }
123
124 /* Context: QEMU global mutex held */
125 int virtio_scsi_dataplane_start(VirtIODevice *vdev)
126 {
127 int i;
128 int rc;
129 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
130 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
131 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
132 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
133
134 if (s->dataplane_started ||
135 s->dataplane_starting ||
136 s->dataplane_fenced) {
137 return 0;
138 }
139
140 s->dataplane_starting = true;
141
142 /* Set up guest notifier (irq) */
143 rc = k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, true);
144 if (rc != 0) {
145 error_report("virtio-scsi: Failed to set guest notifiers (%d), "
146 "ensure -accel kvm is set.", rc);
147 goto fail_guest_notifiers;
148 }
149
150 aio_context_acquire(s->ctx);
151 rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0,
152 virtio_scsi_data_plane_handle_ctrl);
153 if (rc) {
154 goto fail_vrings;
155 }
156 rc = virtio_scsi_vring_init(s, vs->event_vq, 1,
157 virtio_scsi_data_plane_handle_event);
158 if (rc) {
159 goto fail_vrings;
160 }
161 for (i = 0; i < vs->conf.num_queues; i++) {
162 rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2,
163 virtio_scsi_data_plane_handle_cmd);
164 if (rc) {
165 goto fail_vrings;
166 }
167 }
168
169 s->dataplane_starting = false;
170 s->dataplane_started = true;
171 aio_context_release(s->ctx);
172 return 0;
173
174 fail_vrings:
175 aio_wait_bh_oneshot(s->ctx, virtio_scsi_dataplane_stop_bh, s);
176 aio_context_release(s->ctx);
177 for (i = 0; i < vs->conf.num_queues + 2; i++) {
178 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
179 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
180 }
181 k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
182 fail_guest_notifiers:
183 s->dataplane_fenced = true;
184 s->dataplane_starting = false;
185 s->dataplane_started = true;
186 return -ENOSYS;
187 }
188
189 /* Context: QEMU global mutex held */
190 void virtio_scsi_dataplane_stop(VirtIODevice *vdev)
191 {
192 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
193 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
194 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
195 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
196 int i;
197
198 if (!s->dataplane_started || s->dataplane_stopping) {
199 return;
200 }
201
202 /* Better luck next time. */
203 if (s->dataplane_fenced) {
204 s->dataplane_fenced = false;
205 s->dataplane_started = false;
206 return;
207 }
208 s->dataplane_stopping = true;
209
210 aio_context_acquire(s->ctx);
211 aio_wait_bh_oneshot(s->ctx, virtio_scsi_dataplane_stop_bh, s);
212 aio_context_release(s->ctx);
213
214 blk_drain_all(); /* ensure there are no in-flight requests */
215
216 for (i = 0; i < vs->conf.num_queues + 2; i++) {
217 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
218 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
219 }
220
221 /* Clean up guest notifier (irq) */
222 k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
223 s->dataplane_stopping = false;
224 s->dataplane_started = false;
225 }