2 * Virtio SCSI dataplane
4 * Copyright Red Hat, Inc. 2014
7 * Fam Zheng <famz@redhat.com>
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.
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"
24 /* Context: QEMU global mutex held */
25 void virtio_scsi_dataplane_setup(VirtIOSCSI
*s
, Error
**errp
)
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
);
32 if (vs
->conf
.iothread
) {
33 if (!k
->set_guest_notifiers
|| !k
->ioeventfd_assign
) {
35 "device is incompatible with iothread "
36 "(transport does not support notifiers)");
39 if (!virtio_device_ioeventfd_enabled(vdev
)) {
40 error_setg(errp
, "ioeventfd is required for iothread");
43 s
->ctx
= iothread_get_aio_context(vs
->conf
.iothread
);
45 if (!virtio_device_ioeventfd_enabled(vdev
)) {
48 s
->ctx
= qemu_get_aio_context();
52 static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice
*vdev
,
55 bool progress
= false;
56 VirtIOSCSI
*s
= VIRTIO_SCSI(vdev
);
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
);
63 virtio_scsi_release(s
);
67 static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice
*vdev
,
70 bool progress
= false;
71 VirtIOSCSI
*s
= VIRTIO_SCSI(vdev
);
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
);
78 virtio_scsi_release(s
);
82 static bool virtio_scsi_data_plane_handle_event(VirtIODevice
*vdev
,
85 bool progress
= false;
86 VirtIOSCSI
*s
= VIRTIO_SCSI(vdev
);
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
);
93 virtio_scsi_release(s
);
97 static int virtio_scsi_set_host_notifier(VirtIOSCSI
*s
, VirtQueue
*vq
, int n
)
99 BusState
*qbus
= BUS(qdev_get_parent_bus(DEVICE(s
)));
102 /* Set up virtqueue notify */
103 rc
= virtio_bus_set_host_notifier(VIRTIO_BUS(qbus
), n
, true);
105 fprintf(stderr
, "virtio-scsi: Failed to set host notifier (%d)\n",
107 s
->dataplane_fenced
= true;
114 /* Context: BH in IOThread */
115 static void virtio_scsi_dataplane_stop_bh(void *opaque
)
117 VirtIOSCSI
*s
= opaque
;
118 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
121 virtio_queue_aio_set_host_notifier_handler(vs
->ctrl_vq
, s
->ctx
, NULL
);
122 virtio_queue_aio_set_host_notifier_handler(vs
->event_vq
, s
->ctx
, NULL
);
123 for (i
= 0; i
< vs
->conf
.num_queues
; i
++) {
124 virtio_queue_aio_set_host_notifier_handler(vs
->cmd_vqs
[i
], s
->ctx
, NULL
);
128 /* Context: QEMU global mutex held */
129 int virtio_scsi_dataplane_start(VirtIODevice
*vdev
)
133 int vq_init_count
= 0;
134 BusState
*qbus
= qdev_get_parent_bus(DEVICE(vdev
));
135 VirtioBusClass
*k
= VIRTIO_BUS_GET_CLASS(qbus
);
136 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(vdev
);
137 VirtIOSCSI
*s
= VIRTIO_SCSI(vdev
);
139 if (s
->dataplane_started
||
140 s
->dataplane_starting
||
141 s
->dataplane_fenced
) {
145 s
->dataplane_starting
= true;
147 /* Set up guest notifier (irq) */
148 rc
= k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, true);
150 error_report("virtio-scsi: Failed to set guest notifiers (%d), "
151 "ensure -accel kvm is set.", rc
);
152 goto fail_guest_notifiers
;
155 memory_region_transaction_begin();
157 rc
= virtio_scsi_set_host_notifier(s
, vs
->ctrl_vq
, 0);
159 goto fail_host_notifiers
;
163 rc
= virtio_scsi_set_host_notifier(s
, vs
->event_vq
, 1);
165 goto fail_host_notifiers
;
170 for (i
= 0; i
< vs
->conf
.num_queues
; i
++) {
171 rc
= virtio_scsi_set_host_notifier(s
, vs
->cmd_vqs
[i
], i
+ 2);
173 goto fail_host_notifiers
;
178 memory_region_transaction_commit();
180 aio_context_acquire(s
->ctx
);
181 virtio_queue_aio_set_host_notifier_handler(vs
->ctrl_vq
, s
->ctx
,
182 virtio_scsi_data_plane_handle_ctrl
);
183 virtio_queue_aio_set_host_notifier_handler(vs
->event_vq
, s
->ctx
,
184 virtio_scsi_data_plane_handle_event
);
186 for (i
= 0; i
< vs
->conf
.num_queues
; i
++) {
187 virtio_queue_aio_set_host_notifier_handler(vs
->cmd_vqs
[i
], s
->ctx
,
188 virtio_scsi_data_plane_handle_cmd
);
191 s
->dataplane_starting
= false;
192 s
->dataplane_started
= true;
193 aio_context_release(s
->ctx
);
197 for (i
= 0; i
< vq_init_count
; i
++) {
198 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus
), i
, false);
201 memory_region_transaction_commit();
203 for (i
= 0; i
< vq_init_count
; i
++) {
204 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus
), i
);
206 k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, false);
207 fail_guest_notifiers
:
208 s
->dataplane_fenced
= true;
209 s
->dataplane_starting
= false;
210 s
->dataplane_started
= true;
214 /* Context: QEMU global mutex held */
215 void virtio_scsi_dataplane_stop(VirtIODevice
*vdev
)
217 BusState
*qbus
= qdev_get_parent_bus(DEVICE(vdev
));
218 VirtioBusClass
*k
= VIRTIO_BUS_GET_CLASS(qbus
);
219 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(vdev
);
220 VirtIOSCSI
*s
= VIRTIO_SCSI(vdev
);
223 if (!s
->dataplane_started
|| s
->dataplane_stopping
) {
227 /* Better luck next time. */
228 if (s
->dataplane_fenced
) {
229 s
->dataplane_fenced
= false;
230 s
->dataplane_started
= false;
233 s
->dataplane_stopping
= true;
235 aio_context_acquire(s
->ctx
);
236 aio_wait_bh_oneshot(s
->ctx
, virtio_scsi_dataplane_stop_bh
, s
);
237 aio_context_release(s
->ctx
);
239 blk_drain_all(); /* ensure there are no in-flight requests */
241 memory_region_transaction_begin();
243 for (i
= 0; i
< vs
->conf
.num_queues
+ 2; i
++) {
244 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus
), i
, false);
247 memory_region_transaction_commit();
249 for (i
= 0; i
< vs
->conf
.num_queues
+ 2; i
++) {
250 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus
), i
);
253 /* Clean up guest notifier (irq) */
254 k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, false);
255 s
->dataplane_stopping
= false;
256 s
->dataplane_started
= false;