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authorPaolo Bonzini <pbonzini@redhat.com>2016-02-14 18:17:10 +0100
committerMichael S. Tsirkin <mst@redhat.com>2016-02-25 13:14:19 +0200
commite24a47c5b73e04f94030e2daa356c7582aebfca2 (patch)
treefe1cb88c3eaf96ac96c0a963f913c043720b37b2 /hw/scsi
parent03de2f527499ae0c6d16a379665d072345254f2c (diff)
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virtio-scsi: do not use vring in dataplane
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/scsi')
-rw-r--r--hw/scsi/virtio-scsi-dataplane.c196
-rw-r--r--hw/scsi/virtio-scsi.c52
2 files changed, 34 insertions, 214 deletions
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 8340326..367e476 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -39,14 +39,10 @@ void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread)
}
}
-static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s,
- VirtQueue *vq,
- EventNotifierHandler *handler,
- int n)
+static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
- VirtIOSCSIVring *r;
int rc;
/* Set up virtqueue notify */
@@ -55,105 +51,17 @@ static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s,
fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n",
rc);
s->dataplane_fenced = true;
- return NULL;
+ return rc;
}
- r = g_new(VirtIOSCSIVring, 1);
- r->host_notifier = *virtio_queue_get_host_notifier(vq);
- r->guest_notifier = *virtio_queue_get_guest_notifier(vq);
- aio_set_event_notifier(s->ctx, &r->host_notifier, true, handler);
-
- r->parent = s;
-
- if (!vring_setup(&r->vring, VIRTIO_DEVICE(s), n)) {
- fprintf(stderr, "virtio-scsi: VRing setup failed\n");
- goto fail_vring;
- }
- return r;
-
-fail_vring:
- aio_set_event_notifier(s->ctx, &r->host_notifier, true, NULL);
- k->set_host_notifier(qbus->parent, n, false);
- g_free(r);
- return NULL;
-}
-
-VirtIOSCSIReq *virtio_scsi_pop_req_vring(VirtIOSCSI *s,
- VirtIOSCSIVring *vring)
-{
- VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
- VirtIOSCSIReq *req;
-
- req = vring_pop((VirtIODevice *)s, &vring->vring,
- sizeof(VirtIOSCSIReq) + vs->cdb_size);
- if (!req) {
- return NULL;
- }
- virtio_scsi_init_req(s, NULL, req);
- req->vring = vring;
- return req;
-}
-
-void virtio_scsi_vring_push_notify(VirtIOSCSIReq *req)
-{
- VirtIODevice *vdev = VIRTIO_DEVICE(req->vring->parent);
-
- vring_push(vdev, &req->vring->vring, &req->elem,
- req->qsgl.size + req->resp_iov.size);
-
- if (vring_should_notify(vdev, &req->vring->vring)) {
- event_notifier_set(&req->vring->guest_notifier);
- }
+ virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, true, true);
+ return 0;
}
-static void virtio_scsi_iothread_handle_ctrl(EventNotifier *notifier)
+void virtio_scsi_dataplane_notify(VirtIODevice *vdev, VirtIOSCSIReq *req)
{
- VirtIOSCSIVring *vring = container_of(notifier,
- VirtIOSCSIVring, host_notifier);
- VirtIOSCSI *s = VIRTIO_SCSI(vring->parent);
- VirtIOSCSIReq *req;
-
- event_notifier_test_and_clear(notifier);
- while ((req = virtio_scsi_pop_req_vring(s, vring))) {
- virtio_scsi_handle_ctrl_req(s, req);
- }
-}
-
-static void virtio_scsi_iothread_handle_event(EventNotifier *notifier)
-{
- VirtIOSCSIVring *vring = container_of(notifier,
- VirtIOSCSIVring, host_notifier);
- VirtIOSCSI *s = vring->parent;
- VirtIODevice *vdev = VIRTIO_DEVICE(s);
-
- event_notifier_test_and_clear(notifier);
-
- if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
- return;
- }
-
- if (s->events_dropped) {
- virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
- }
-}
-
-static void virtio_scsi_iothread_handle_cmd(EventNotifier *notifier)
-{
- VirtIOSCSIVring *vring = container_of(notifier,
- VirtIOSCSIVring, host_notifier);
- VirtIOSCSI *s = (VirtIOSCSI *)vring->parent;
- VirtIOSCSIReq *req, *next;
- QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
-
- event_notifier_test_and_clear(notifier);
- while ((req = virtio_scsi_pop_req_vring(s, vring))) {
- if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
- QTAILQ_INSERT_TAIL(&reqs, req, next);
- }
- }
-
- QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
- virtio_scsi_handle_cmd_req_submit(s, req);
+ if (virtio_should_notify(vdev, req->vq)) {
+ event_notifier_set(virtio_queue_get_guest_notifier(req->vq));
}
}
@@ -163,46 +71,10 @@ static void virtio_scsi_clear_aio(VirtIOSCSI *s)
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
int i;
- if (s->ctrl_vring) {
- aio_set_event_notifier(s->ctx, &s->ctrl_vring->host_notifier,
- true, NULL);
- }
- if (s->event_vring) {
- aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier,
- true, NULL);
- }
- if (s->cmd_vrings) {
- for (i = 0; i < vs->conf.num_queues && s->cmd_vrings[i]; i++) {
- aio_set_event_notifier(s->ctx, &s->cmd_vrings[i]->host_notifier,
- true, NULL);
- }
- }
-}
-
-static void virtio_scsi_vring_teardown(VirtIOSCSI *s)
-{
- VirtIODevice *vdev = VIRTIO_DEVICE(s);
- VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
- int i;
-
- if (s->ctrl_vring) {
- vring_teardown(&s->ctrl_vring->vring, vdev, 0);
- g_free(s->ctrl_vring);
- s->ctrl_vring = NULL;
- }
- if (s->event_vring) {
- vring_teardown(&s->event_vring->vring, vdev, 1);
- g_free(s->event_vring);
- s->event_vring = NULL;
- }
- if (s->cmd_vrings) {
- for (i = 0; i < vs->conf.num_queues && s->cmd_vrings[i]; i++) {
- vring_teardown(&s->cmd_vrings[i]->vring, vdev, 2 + i);
- g_free(s->cmd_vrings[i]);
- s->cmd_vrings[i] = NULL;
- }
- free(s->cmd_vrings);
- s->cmd_vrings = NULL;
+ virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, false, false);
+ virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, false, false);
+ for (i = 0; i < vs->conf.num_queues; i++) {
+ virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, false, false);
}
}
@@ -229,30 +101,21 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s)
if (rc != 0) {
fprintf(stderr, "virtio-scsi: Failed to set guest notifiers (%d), "
"ensure -enable-kvm is set\n", rc);
- s->dataplane_fenced = true;
goto fail_guest_notifiers;
}
aio_context_acquire(s->ctx);
- s->ctrl_vring = virtio_scsi_vring_init(s, vs->ctrl_vq,
- virtio_scsi_iothread_handle_ctrl,
- 0);
- if (!s->ctrl_vring) {
+ rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0);
+ if (rc) {
goto fail_vrings;
}
- s->event_vring = virtio_scsi_vring_init(s, vs->event_vq,
- virtio_scsi_iothread_handle_event,
- 1);
- if (!s->event_vring) {
+ rc = virtio_scsi_vring_init(s, vs->event_vq, 1);
+ if (rc) {
goto fail_vrings;
}
- s->cmd_vrings = g_new(VirtIOSCSIVring *, vs->conf.num_queues);
for (i = 0; i < vs->conf.num_queues; i++) {
- s->cmd_vrings[i] =
- virtio_scsi_vring_init(s, vs->cmd_vqs[i],
- virtio_scsi_iothread_handle_cmd,
- i + 2);
- if (!s->cmd_vrings[i]) {
+ rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2);
+ if (rc) {
goto fail_vrings;
}
}
@@ -265,13 +128,14 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s)
fail_vrings:
virtio_scsi_clear_aio(s);
aio_context_release(s->ctx);
- virtio_scsi_vring_teardown(s);
for (i = 0; i < vs->conf.num_queues + 2; i++) {
k->set_host_notifier(qbus->parent, i, false);
}
k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
fail_guest_notifiers:
+ s->dataplane_fenced = true;
s->dataplane_starting = false;
+ s->dataplane_started = true;
}
/* Context: QEMU global mutex held */
@@ -282,12 +146,14 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
int i;
+ if (!s->dataplane_started || s->dataplane_stopping) {
+ return;
+ }
+
/* Better luck next time. */
if (s->dataplane_fenced) {
s->dataplane_fenced = false;
- return;
- }
- if (!s->dataplane_started || s->dataplane_stopping) {
+ s->dataplane_started = false;
return;
}
s->dataplane_stopping = true;
@@ -295,24 +161,12 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
aio_context_acquire(s->ctx);
- aio_set_event_notifier(s->ctx, &s->ctrl_vring->host_notifier,
- true, NULL);
- aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier,
- true, NULL);
- for (i = 0; i < vs->conf.num_queues; i++) {
- aio_set_event_notifier(s->ctx, &s->cmd_vrings[i]->host_notifier,
- true, NULL);
- }
+ virtio_scsi_clear_aio(s);
blk_drain_all(); /* ensure there are no in-flight requests */
aio_context_release(s->ctx);
- /* Sync vring state back to virtqueue so that non-dataplane request
- * processing can continue when we disable the host notifier below.
- */
- virtio_scsi_vring_teardown(s);
-
for (i = 0; i < vs->conf.num_queues + 2; i++) {
k->set_host_notifier(qbus->parent, i, false);
}
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 5b29bac..0c30d2e 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -23,7 +23,6 @@
#include <block/scsi.h>
#include <hw/virtio/virtio-bus.h>
#include "hw/virtio/virtio-access.h"
-#include "migration/migration.h"
static inline int virtio_scsi_get_lun(uint8_t *lun)
{
@@ -43,7 +42,8 @@ static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
{
- const size_t zero_skip = offsetof(VirtIOSCSIReq, vring);
+ const size_t zero_skip =
+ offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
req->vq = vq;
req->dev = s;
@@ -66,11 +66,10 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
VirtIODevice *vdev = VIRTIO_DEVICE(s);
qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
- if (req->vring) {
- assert(req->vq == NULL);
- virtio_scsi_vring_push_notify(req);
+ virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
+ if (s->dataplane_started) {
+ virtio_scsi_dataplane_notify(vdev, req);
} else {
- virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
virtio_notify(vdev, vq);
}
@@ -417,7 +416,7 @@ static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
VirtIOSCSI *s = (VirtIOSCSI *)vdev;
VirtIOSCSIReq *req;
- if (s->ctx && !s->dataplane_disabled) {
+ if (s->ctx && !s->dataplane_started) {
virtio_scsi_dataplane_start(s);
return;
}
@@ -567,7 +566,7 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
VirtIOSCSIReq *req, *next;
QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
- if (s->ctx && !s->dataplane_disabled) {
+ if (s->ctx && !s->dataplane_started) {
virtio_scsi_dataplane_start(s);
return;
}
@@ -687,11 +686,7 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
aio_context_acquire(s->ctx);
}
- if (s->dataplane_started) {
- req = virtio_scsi_pop_req_vring(s, s->event_vring);
- } else {
- req = virtio_scsi_pop_req(s, vs->event_vq);
- }
+ req = virtio_scsi_pop_req(s, vs->event_vq);
if (!req) {
s->events_dropped = true;
goto out;
@@ -733,7 +728,7 @@ static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
- if (s->ctx && !s->dataplane_disabled) {
+ if (s->ctx && !s->dataplane_started) {
virtio_scsi_dataplane_start(s);
return;
}
@@ -901,31 +896,6 @@ void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
}
}
-/* Disable dataplane thread during live migration since it does not
- * update the dirty memory bitmap yet.
- */
-static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
-{
- VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
- migration_state_notifier);
- MigrationState *mig = data;
-
- if (migration_in_setup(mig)) {
- if (!s->dataplane_started) {
- return;
- }
- virtio_scsi_dataplane_stop(s);
- s->dataplane_disabled = true;
- } else if (migration_has_finished(mig) ||
- migration_has_failed(mig)) {
- if (s->dataplane_started) {
- return;
- }
- blk_drain_all(); /* complete in-flight non-dataplane requests */
- s->dataplane_disabled = false;
- }
-}
-
static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
@@ -956,8 +926,6 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
virtio_scsi_save, virtio_scsi_load, s);
- s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
- add_migration_state_change_notifier(&s->migration_state_notifier);
error_setg(&s->blocker, "block device is in use by data plane");
@@ -991,8 +959,6 @@ static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
error_free(s->blocker);
unregister_savevm(dev, "virtio-scsi", s);
- remove_migration_state_change_notifier(&s->migration_state_notifier);
-
virtio_scsi_common_unrealize(dev, errp);
}