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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
25void 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
52static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev,
53 VirtQueue *vq)
54{
55 bool progress = false;
56 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
57
58 virtio_scsi_acquire(s);
59 if (!s->dataplane_fenced) {
60 assert(s->ctx && s->dataplane_started);
61 progress = virtio_scsi_handle_cmd_vq(s, vq);
62 }
63 virtio_scsi_release(s);
64 return progress;
65}
66
67static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev,
68 VirtQueue *vq)
69{
70 bool progress = false;
71 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
72
73 virtio_scsi_acquire(s);
74 if (!s->dataplane_fenced) {
75 assert(s->ctx && s->dataplane_started);
76 progress = virtio_scsi_handle_ctrl_vq(s, vq);
77 }
78 virtio_scsi_release(s);
79 return progress;
80}
81
82static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev,
83 VirtQueue *vq)
84{
85 bool progress = false;
86 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
87
88 virtio_scsi_acquire(s);
89 if (!s->dataplane_fenced) {
90 assert(s->ctx && s->dataplane_started);
91 progress = virtio_scsi_handle_event_vq(s, vq);
92 }
93 virtio_scsi_release(s);
94 return progress;
95}
96
97static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n,
98 VirtIOHandleAIOOutput fn)
99{
100 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
101 int rc;
102
103
104 rc = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), n, true);
105 if (rc != 0) {
106 fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n",
107 rc);
108 s->dataplane_fenced = true;
109 return rc;
110 }
111
112 virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, fn);
113 return 0;
114}
115
116
117static void virtio_scsi_dataplane_stop_bh(void *opaque)
118{
119 VirtIOSCSI *s = opaque;
120 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
121 int i;
122
123 virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, NULL);
124 virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, NULL);
125 for (i = 0; i < vs->conf.num_queues; i++) {
126 virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, NULL);
127 }
128}
129
130
131int virtio_scsi_dataplane_start(VirtIODevice *vdev)
132{
133 int i;
134 int rc;
135 int vq_init_count = 0;
136 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
137 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
138 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
139 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
140
141 if (s->dataplane_started ||
142 s->dataplane_starting ||
143 s->dataplane_fenced) {
144 return 0;
145 }
146
147 s->dataplane_starting = true;
148
149
150 rc = k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, true);
151 if (rc != 0) {
152 error_report("virtio-scsi: Failed to set guest notifiers (%d), "
153 "ensure -accel kvm is set.", rc);
154 goto fail_guest_notifiers;
155 }
156
157 aio_context_acquire(s->ctx);
158 rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0,
159 virtio_scsi_data_plane_handle_ctrl);
160 if (rc) {
161 goto fail_vrings;
162 }
163
164 vq_init_count++;
165 rc = virtio_scsi_vring_init(s, vs->event_vq, 1,
166 virtio_scsi_data_plane_handle_event);
167 if (rc) {
168 goto fail_vrings;
169 }
170
171 vq_init_count++;
172 for (i = 0; i < vs->conf.num_queues; i++) {
173 rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2,
174 virtio_scsi_data_plane_handle_cmd);
175 if (rc) {
176 goto fail_vrings;
177 }
178 vq_init_count++;
179 }
180
181 s->dataplane_starting = false;
182 s->dataplane_started = true;
183 aio_context_release(s->ctx);
184 return 0;
185
186fail_vrings:
187 aio_wait_bh_oneshot(s->ctx, virtio_scsi_dataplane_stop_bh, s);
188 aio_context_release(s->ctx);
189 for (i = 0; i < vq_init_count; i++) {
190 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
191 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
192 }
193 k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
194fail_guest_notifiers:
195 s->dataplane_fenced = true;
196 s->dataplane_starting = false;
197 s->dataplane_started = true;
198 return -ENOSYS;
199}
200
201
202void virtio_scsi_dataplane_stop(VirtIODevice *vdev)
203{
204 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
205 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
206 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
207 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
208 int i;
209
210 if (!s->dataplane_started || s->dataplane_stopping) {
211 return;
212 }
213
214
215 if (s->dataplane_fenced) {
216 s->dataplane_fenced = false;
217 s->dataplane_started = false;
218 return;
219 }
220 s->dataplane_stopping = true;
221
222 aio_context_acquire(s->ctx);
223 aio_wait_bh_oneshot(s->ctx, virtio_scsi_dataplane_stop_bh, s);
224 aio_context_release(s->ctx);
225
226 blk_drain_all();
227
228 for (i = 0; i < vs->conf.num_queues + 2; i++) {
229 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
230 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
231 }
232
233
234 k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
235 s->dataplane_stopping = false;
236 s->dataplane_started = false;
237}
238
