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
);
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",
56 s
->dataplane_fenced
= true;
60 r
= g_new(VirtIOSCSIVring
, 1);
61 r
->host_notifier
= *virtio_queue_get_host_notifier(vq
);
62 r
->guest_notifier
= *virtio_queue_get_guest_notifier(vq
);
63 aio_set_event_notifier(s
->ctx
, &r
->host_notifier
, false,
68 if (!vring_setup(&r
->vring
, VIRTIO_DEVICE(s
), n
)) {
69 fprintf(stderr
, "virtio-scsi: VRing setup failed\n");
75 aio_set_event_notifier(s
->ctx
, &r
->host_notifier
, false,
77 k
->set_host_notifier(qbus
->parent
, n
, false);
82 VirtIOSCSIReq
*virtio_scsi_pop_req_vring(VirtIOSCSI
*s
,
83 VirtIOSCSIVring
*vring
)
85 VirtIOSCSIReq
*req
= virtio_scsi_init_req(s
, NULL
);
89 r
= vring_pop((VirtIODevice
*)s
, &vring
->vring
, &req
->elem
);
91 virtio_scsi_free_req(req
);
97 void virtio_scsi_vring_push_notify(VirtIOSCSIReq
*req
)
99 VirtIODevice
*vdev
= VIRTIO_DEVICE(req
->vring
->parent
);
101 vring_push(vdev
, &req
->vring
->vring
, &req
->elem
,
102 req
->qsgl
.size
+ req
->resp_iov
.size
);
104 if (vring_should_notify(vdev
, &req
->vring
->vring
)) {
105 event_notifier_set(&req
->vring
->guest_notifier
);
109 static void virtio_scsi_iothread_handle_ctrl(EventNotifier
*notifier
)
111 VirtIOSCSIVring
*vring
= container_of(notifier
,
112 VirtIOSCSIVring
, host_notifier
);
113 VirtIOSCSI
*s
= VIRTIO_SCSI(vring
->parent
);
116 event_notifier_test_and_clear(notifier
);
117 while ((req
= virtio_scsi_pop_req_vring(s
, vring
))) {
118 virtio_scsi_handle_ctrl_req(s
, req
);
122 static void virtio_scsi_iothread_handle_event(EventNotifier
*notifier
)
124 VirtIOSCSIVring
*vring
= container_of(notifier
,
125 VirtIOSCSIVring
, host_notifier
);
126 VirtIOSCSI
*s
= vring
->parent
;
127 VirtIODevice
*vdev
= VIRTIO_DEVICE(s
);
129 event_notifier_test_and_clear(notifier
);
131 if (!(vdev
->status
& VIRTIO_CONFIG_S_DRIVER_OK
)) {
135 if (s
->events_dropped
) {
136 virtio_scsi_push_event(s
, NULL
, VIRTIO_SCSI_T_NO_EVENT
, 0);
140 static void virtio_scsi_iothread_handle_cmd(EventNotifier
*notifier
)
142 VirtIOSCSIVring
*vring
= container_of(notifier
,
143 VirtIOSCSIVring
, host_notifier
);
144 VirtIOSCSI
*s
= (VirtIOSCSI
*)vring
->parent
;
145 VirtIOSCSIReq
*req
, *next
;
146 QTAILQ_HEAD(, VirtIOSCSIReq
) reqs
= QTAILQ_HEAD_INITIALIZER(reqs
);
148 event_notifier_test_and_clear(notifier
);
149 while ((req
= virtio_scsi_pop_req_vring(s
, vring
))) {
150 if (virtio_scsi_handle_cmd_req_prepare(s
, req
)) {
151 QTAILQ_INSERT_TAIL(&reqs
, req
, next
);
155 QTAILQ_FOREACH_SAFE(req
, &reqs
, next
, next
) {
156 virtio_scsi_handle_cmd_req_submit(s
, req
);
160 /* assumes s->ctx held */
161 static void virtio_scsi_clear_aio(VirtIOSCSI
*s
)
163 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
167 aio_set_event_notifier(s
->ctx
, &s
->ctrl_vring
->host_notifier
,
170 if (s
->event_vring
) {
171 aio_set_event_notifier(s
->ctx
, &s
->event_vring
->host_notifier
,
175 for (i
= 0; i
< vs
->conf
.num_queues
&& s
->cmd_vrings
[i
]; i
++) {
176 aio_set_event_notifier(s
->ctx
, &s
->cmd_vrings
[i
]->host_notifier
,
182 static void virtio_scsi_vring_teardown(VirtIOSCSI
*s
)
184 VirtIODevice
*vdev
= VIRTIO_DEVICE(s
);
185 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
189 vring_teardown(&s
->ctrl_vring
->vring
, vdev
, 0);
190 g_free(s
->ctrl_vring
);
191 s
->ctrl_vring
= NULL
;
193 if (s
->event_vring
) {
194 vring_teardown(&s
->event_vring
->vring
, vdev
, 1);
195 g_free(s
->event_vring
);
196 s
->event_vring
= NULL
;
199 for (i
= 0; i
< vs
->conf
.num_queues
&& s
->cmd_vrings
[i
]; i
++) {
200 vring_teardown(&s
->cmd_vrings
[i
]->vring
, vdev
, 2 + i
);
201 g_free(s
->cmd_vrings
[i
]);
202 s
->cmd_vrings
[i
] = NULL
;
205 s
->cmd_vrings
= NULL
;
209 /* Context: QEMU global mutex held */
210 void virtio_scsi_dataplane_start(VirtIOSCSI
*s
)
214 BusState
*qbus
= BUS(qdev_get_parent_bus(DEVICE(s
)));
215 VirtioBusClass
*k
= VIRTIO_BUS_GET_CLASS(qbus
);
216 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
218 if (s
->dataplane_started
||
219 s
->dataplane_starting
||
220 s
->dataplane_fenced
||
221 s
->ctx
!= iothread_get_aio_context(vs
->conf
.iothread
)) {
225 s
->dataplane_starting
= true;
227 /* Set up guest notifier (irq) */
228 rc
= k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, true);
230 fprintf(stderr
, "virtio-scsi: Failed to set guest notifiers (%d), "
231 "ensure -enable-kvm is set\n", rc
);
232 s
->dataplane_fenced
= true;
233 goto fail_guest_notifiers
;
236 aio_context_acquire(s
->ctx
);
237 s
->ctrl_vring
= virtio_scsi_vring_init(s
, vs
->ctrl_vq
,
238 virtio_scsi_iothread_handle_ctrl
,
240 if (!s
->ctrl_vring
) {
243 s
->event_vring
= virtio_scsi_vring_init(s
, vs
->event_vq
,
244 virtio_scsi_iothread_handle_event
,
246 if (!s
->event_vring
) {
249 s
->cmd_vrings
= g_new(VirtIOSCSIVring
*, vs
->conf
.num_queues
);
250 for (i
= 0; i
< vs
->conf
.num_queues
; i
++) {
252 virtio_scsi_vring_init(s
, vs
->cmd_vqs
[i
],
253 virtio_scsi_iothread_handle_cmd
,
255 if (!s
->cmd_vrings
[i
]) {
260 s
->dataplane_starting
= false;
261 s
->dataplane_started
= true;
262 aio_context_release(s
->ctx
);
266 virtio_scsi_clear_aio(s
);
267 aio_context_release(s
->ctx
);
268 virtio_scsi_vring_teardown(s
);
269 for (i
= 0; i
< vs
->conf
.num_queues
+ 2; i
++) {
270 k
->set_host_notifier(qbus
->parent
, i
, false);
272 k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, false);
273 fail_guest_notifiers
:
274 s
->dataplane_starting
= false;
277 /* Context: QEMU global mutex held */
278 void virtio_scsi_dataplane_stop(VirtIOSCSI
*s
)
280 BusState
*qbus
= BUS(qdev_get_parent_bus(DEVICE(s
)));
281 VirtioBusClass
*k
= VIRTIO_BUS_GET_CLASS(qbus
);
282 VirtIOSCSICommon
*vs
= VIRTIO_SCSI_COMMON(s
);
285 /* Better luck next time. */
286 if (s
->dataplane_fenced
) {
287 s
->dataplane_fenced
= false;
290 if (!s
->dataplane_started
|| s
->dataplane_stopping
) {
293 s
->dataplane_stopping
= true;
294 assert(s
->ctx
== iothread_get_aio_context(vs
->conf
.iothread
));
296 aio_context_acquire(s
->ctx
);
298 aio_set_event_notifier(s
->ctx
, &s
->ctrl_vring
->host_notifier
,
300 aio_set_event_notifier(s
->ctx
, &s
->event_vring
->host_notifier
,
302 for (i
= 0; i
< vs
->conf
.num_queues
; i
++) {
303 aio_set_event_notifier(s
->ctx
, &s
->cmd_vrings
[i
]->host_notifier
,
307 blk_drain_all(); /* ensure there are no in-flight requests */
309 aio_context_release(s
->ctx
);
311 /* Sync vring state back to virtqueue so that non-dataplane request
312 * processing can continue when we disable the host notifier below.
314 virtio_scsi_vring_teardown(s
);
316 for (i
= 0; i
< vs
->conf
.num_queues
+ 2; i
++) {
317 k
->set_host_notifier(qbus
->parent
, i
, false);
320 /* Clean up guest notifier (irq) */
321 k
->set_guest_notifiers(qbus
->parent
, vs
->conf
.num_queues
+ 2, false);
322 s
->dataplane_stopping
= false;
323 s
->dataplane_started
= false;