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