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 "hw/virtio/virtio-scsi.h"
15 #include "qemu/error-report.h"
16 #include "sysemu/block-backend.h"
17 #include <hw/scsi/scsi.h>
18 #include <block/scsi.h>
19 #include <hw/virtio/virtio-bus.h>
20 #include "hw/virtio/virtio-access.h"
23 /* Context: QEMU global mutex held */
24 void virtio_scsi_set_iothread(VirtIOSCSI
*s
, IOThread
*iothread
)
26 BusState
*qbus
= BUS(qdev_get_parent_bus(DEVICE(s
)));
27 VirtioBusClass
*k
= VIRTIO_BUS_GET_CLASS(qbus
);
28 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
31 s
->ctx
= iothread_get_aio_context(vs
->conf
.iothread
);
33 /* Don't try if transport does not support notifiers. */
34 if (!k
->set_guest_notifiers
|| !k
->set_host_notifier
) {
35 fprintf(stderr
, "virtio-scsi: Failed to set iothread "
36 "(transport does not support notifiers)");
41 static VirtIOSCSIVring
*virtio_scsi_vring_init(VirtIOSCSI
*s
,
43 EventNotifierHandler
*handler
,
46 BusState
*qbus
= BUS(qdev_get_parent_bus(DEVICE(s
)));
47 VirtioBusClass
*k
= VIRTIO_BUS_GET_CLASS(qbus
);
48 VirtIOSCSIVring
*r
= g_slice_new(VirtIOSCSIVring
);
51 /* Set up virtqueue notify */
52 rc
= k
->set_host_notifier(qbus
->parent
, n
, true);
54 fprintf(stderr
, "virtio-scsi: Failed to set host notifier (%d)\n",
58 r
->host_notifier
= *virtio_queue_get_host_notifier(vq
);
59 r
->guest_notifier
= *virtio_queue_get_guest_notifier(vq
);
60 aio_set_event_notifier(s
->ctx
, &r
->host_notifier
, handler
);
64 if (!vring_setup(&r
->vring
, VIRTIO_DEVICE(s
), n
)) {
65 fprintf(stderr
, "virtio-scsi: VRing setup failed\n");
71 aio_set_event_notifier(s
->ctx
, &r
->host_notifier
, NULL
);
72 k
->set_host_notifier(qbus
->parent
, n
, false);
73 g_slice_free(VirtIOSCSIVring
, r
);
77 VirtIOSCSIReq
*virtio_scsi_pop_req_vring(VirtIOSCSI
*s
,
78 VirtIOSCSIVring
*vring
)
80 VirtIOSCSIReq
*req
= virtio_scsi_init_req(s
, NULL
);
84 r
= vring_pop((VirtIODevice
*)s
, &vring
->vring
, &req
->elem
);
86 virtio_scsi_free_req(req
);
92 void virtio_scsi_vring_push_notify(VirtIOSCSIReq
*req
)
94 vring_push(&req
->vring
->vring
, &req
->elem
,
95 req
->qsgl
.size
+ req
->resp_iov
.size
);
96 event_notifier_set(&req
->vring
->guest_notifier
);
99 static void virtio_scsi_iothread_handle_ctrl(EventNotifier
*notifier
)
101 VirtIOSCSIVring
*vring
= container_of(notifier
,
102 VirtIOSCSIVring
, host_notifier
);
103 VirtIOSCSI
*s
= VIRTIO_SCSI(vring
->parent
);
106 event_notifier_test_and_clear(notifier
);
107 while ((req
= virtio_scsi_pop_req_vring(s
, vring
))) {
108 virtio_scsi_handle_ctrl_req(s
, req
);
112 static void virtio_scsi_iothread_handle_event(EventNotifier
*notifier
)
114 VirtIOSCSIVring
*vring
= container_of(notifier
,
115 VirtIOSCSIVring
, host_notifier
);
116 VirtIOSCSI
*s
= vring
->parent
;
117 VirtIODevice
*vdev
= VIRTIO_DEVICE(s
);
119 event_notifier_test_and_clear(notifier
);
121 if (!(vdev
->status
& VIRTIO_CONFIG_S_DRIVER_OK
)) {
125 if (s
->events_dropped
) {
126 virtio_scsi_push_event(s
, NULL
, VIRTIO_SCSI_T_NO_EVENT
, 0);
130 static void virtio_scsi_iothread_handle_cmd(EventNotifier
*notifier
)
132 VirtIOSCSIVring
*vring
= container_of(notifier
,
133 VirtIOSCSIVring
, host_notifier
);
134 VirtIOSCSI
*s
= (VirtIOSCSI
*)vring
->parent
;
135 VirtIOSCSIReq
*req
, *next
;
136 QTAILQ_HEAD(, VirtIOSCSIReq
) reqs
= QTAILQ_HEAD_INITIALIZER(reqs
);
138 event_notifier_test_and_clear(notifier
);
139 while ((req
= virtio_scsi_pop_req_vring(s
, vring
))) {
140 if (virtio_scsi_handle_cmd_req_prepare(s
, req
)) {
141 QTAILQ_INSERT_TAIL(&reqs
, req
, next
);
145 QTAILQ_FOREACH_SAFE(req
, &reqs
, next
, next
) {
146 virtio_scsi_handle_cmd_req_submit(s
, req
);
150 /* assumes s->ctx held */
151 static void virtio_scsi_clear_aio(VirtIOSCSI
*s
)
153 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
157 aio_set_event_notifier(s
->ctx
, &s
->ctrl_vring
->host_notifier
, NULL
);
159 if (s
->event_vring
) {
160 aio_set_event_notifier(s
->ctx
, &s
->event_vring
->host_notifier
, NULL
);
163 for (i
= 0; i
< vs
->conf
.num_queues
&& s
->cmd_vrings
[i
]; i
++) {
164 aio_set_event_notifier(s
->ctx
, &s
->cmd_vrings
[i
]->host_notifier
, NULL
);
169 static void virtio_scsi_vring_teardown(VirtIOSCSI
*s
)
171 VirtIODevice
*vdev
= VIRTIO_DEVICE(s
);
172 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
176 vring_teardown(&s
->ctrl_vring
->vring
, vdev
, 0);
178 if (s
->event_vring
) {
179 vring_teardown(&s
->event_vring
->vring
, vdev
, 1);
182 for (i
= 0; i
< vs
->conf
.num_queues
&& s
->cmd_vrings
[i
]; i
++) {
183 vring_teardown(&s
->cmd_vrings
[i
]->vring
, vdev
, 2 + i
);
186 s
->cmd_vrings
= NULL
;
190 /* Context: QEMU global mutex held */
191 void virtio_scsi_dataplane_start(VirtIOSCSI
*s
)
195 BusState
*qbus
= BUS(qdev_get_parent_bus(DEVICE(s
)));
196 VirtioBusClass
*k
= VIRTIO_BUS_GET_CLASS(qbus
);
197 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
199 if (s
->dataplane_started
||
200 s
->dataplane_starting
||
201 s
->ctx
!= iothread_get_aio_context(vs
->conf
.iothread
)) {
205 s
->dataplane_starting
= true;
208 error_setg(&s
->blocker
, "block device is in use by data plane");
209 /* Set up guest notifier (irq) */
210 rc
= k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, true);
212 fprintf(stderr
, "virtio-scsi: Failed to set guest notifiers (%d), "
213 "ensure -enable-kvm is set\n", rc
);
214 goto fail_guest_notifiers
;
217 aio_context_acquire(s
->ctx
);
218 s
->ctrl_vring
= virtio_scsi_vring_init(s
, vs
->ctrl_vq
,
219 virtio_scsi_iothread_handle_ctrl
,
221 if (!s
->ctrl_vring
) {
224 s
->event_vring
= virtio_scsi_vring_init(s
, vs
->event_vq
,
225 virtio_scsi_iothread_handle_event
,
227 if (!s
->event_vring
) {
230 s
->cmd_vrings
= g_malloc0(sizeof(VirtIOSCSIVring
) * vs
->conf
.num_queues
);
231 for (i
= 0; i
< vs
->conf
.num_queues
; i
++) {
233 virtio_scsi_vring_init(s
, vs
->cmd_vqs
[i
],
234 virtio_scsi_iothread_handle_cmd
,
236 if (!s
->cmd_vrings
[i
]) {
241 aio_context_release(s
->ctx
);
242 s
->dataplane_starting
= false;
243 s
->dataplane_started
= true;
246 virtio_scsi_clear_aio(s
);
247 aio_context_release(s
->ctx
);
248 virtio_scsi_vring_teardown(s
);
249 for (i
= 0; i
< vs
->conf
.num_queues
+ 2; i
++) {
250 k
->set_host_notifier(qbus
->parent
, i
, false);
252 k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, false);
253 fail_guest_notifiers
:
254 s
->dataplane_starting
= false;
257 /* Context: QEMU global mutex held */
258 void virtio_scsi_dataplane_stop(VirtIOSCSI
*s
)
260 BusState
*qbus
= BUS(qdev_get_parent_bus(DEVICE(s
)));
261 VirtioBusClass
*k
= VIRTIO_BUS_GET_CLASS(qbus
);
262 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
265 if (!s
->dataplane_started
|| s
->dataplane_stopping
) {
268 error_free(s
->blocker
);
270 s
->dataplane_stopping
= true;
271 assert(s
->ctx
== iothread_get_aio_context(vs
->conf
.iothread
));
273 aio_context_acquire(s
->ctx
);
275 aio_set_event_notifier(s
->ctx
, &s
->ctrl_vring
->host_notifier
, NULL
);
276 aio_set_event_notifier(s
->ctx
, &s
->event_vring
->host_notifier
, NULL
);
277 for (i
= 0; i
< vs
->conf
.num_queues
; i
++) {
278 aio_set_event_notifier(s
->ctx
, &s
->cmd_vrings
[i
]->host_notifier
, NULL
);
281 blk_drain_all(); /* ensure there are no in-flight requests */
283 aio_context_release(s
->ctx
);
285 /* Sync vring state back to virtqueue so that non-dataplane request
286 * processing can continue when we disable the host notifier below.
288 virtio_scsi_vring_teardown(s
);
290 for (i
= 0; i
< vs
->conf
.num_queues
+ 2; i
++) {
291 k
->set_host_notifier(qbus
->parent
, i
, false);
294 /* Clean up guest notifier (irq) */
295 k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, false);
296 s
->dataplane_stopping
= false;
297 s
->dataplane_started
= false;