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Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

# gpg: Signature made Fri 09 Mar 2018 13:19:02 GMT
# gpg:                using RSA key 9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  vl: introduce vm_shutdown()
  virtio-scsi: fix race between .ioeventfd_stop() and vq handler
  virtio-blk: fix race between .ioeventfd_stop() and vq handler
  block: add aio_wait_bh_oneshot()
  virtio-blk: dataplane: Don't batch notifications if EVENT_IDX is present
  README: Fix typo 'git-publish'
  block: Fix qemu crash when using scsi-block

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2018-03-09 17:28:16 +00:00
commit e4ae62b802
11 changed files with 122 additions and 85 deletions

2
README
View File

@ -73,7 +73,7 @@ The QEMU website is also maintained under source control.
git clone git://git.qemu.org/qemu-web.git
https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/
A 'git-profile' utility was created to make above process less
A 'git-publish' utility was created to make above process less
cumbersome, and is highly recommended for making regular contributions,
or even just for sending consecutive patch series revisions. It also
requires a working 'git send-email' setup, and by default doesn't

View File

@ -1150,7 +1150,7 @@ int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
typedef struct BlkRwCo {
BlockBackend *blk;
int64_t offset;
QEMUIOVector *qiov;
void *iobuf;
int ret;
BdrvRequestFlags flags;
} BlkRwCo;
@ -1158,17 +1158,19 @@ typedef struct BlkRwCo {
static void blk_read_entry(void *opaque)
{
BlkRwCo *rwco = opaque;
QEMUIOVector *qiov = rwco->iobuf;
rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, rwco->qiov->size,
rwco->qiov, rwco->flags);
rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, qiov->size,
qiov, rwco->flags);
}
static void blk_write_entry(void *opaque)
{
BlkRwCo *rwco = opaque;
QEMUIOVector *qiov = rwco->iobuf;
rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, rwco->qiov->size,
rwco->qiov, rwco->flags);
rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, qiov->size,
qiov, rwco->flags);
}
static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf,
@ -1188,7 +1190,7 @@ static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf,
rwco = (BlkRwCo) {
.blk = blk,
.offset = offset,
.qiov = &qiov,
.iobuf = &qiov,
.flags = flags,
.ret = NOT_DONE,
};
@ -1296,7 +1298,7 @@ static void blk_aio_complete_bh(void *opaque)
}
static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes,
QEMUIOVector *qiov, CoroutineEntry co_entry,
void *iobuf, CoroutineEntry co_entry,
BdrvRequestFlags flags,
BlockCompletionFunc *cb, void *opaque)
{
@ -1308,7 +1310,7 @@ static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes,
acb->rwco = (BlkRwCo) {
.blk = blk,
.offset = offset,
.qiov = qiov,
.iobuf = iobuf,
.flags = flags,
.ret = NOT_DONE,
};
@ -1331,10 +1333,11 @@ static void blk_aio_read_entry(void *opaque)
{
BlkAioEmAIOCB *acb = opaque;
BlkRwCo *rwco = &acb->rwco;
QEMUIOVector *qiov = rwco->iobuf;
assert(rwco->qiov->size == acb->bytes);
assert(qiov->size == acb->bytes);
rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, acb->bytes,
rwco->qiov, rwco->flags);
qiov, rwco->flags);
blk_aio_complete(acb);
}
@ -1342,10 +1345,11 @@ static void blk_aio_write_entry(void *opaque)
{
BlkAioEmAIOCB *acb = opaque;
BlkRwCo *rwco = &acb->rwco;
QEMUIOVector *qiov = rwco->iobuf;
assert(!rwco->qiov || rwco->qiov->size == acb->bytes);
assert(!qiov || qiov->size == acb->bytes);
rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, acb->bytes,
rwco->qiov, rwco->flags);
qiov, rwco->flags);
blk_aio_complete(acb);
}
@ -1474,8 +1478,10 @@ int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
static void blk_ioctl_entry(void *opaque)
{
BlkRwCo *rwco = opaque;
QEMUIOVector *qiov = rwco->iobuf;
rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset,
rwco->qiov->iov[0].iov_base);
qiov->iov[0].iov_base);
}
int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
@ -1488,24 +1494,15 @@ static void blk_aio_ioctl_entry(void *opaque)
BlkAioEmAIOCB *acb = opaque;
BlkRwCo *rwco = &acb->rwco;
rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset,
rwco->qiov->iov[0].iov_base);
rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset, rwco->iobuf);
blk_aio_complete(acb);
}
BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
BlockCompletionFunc *cb, void *opaque)
{
QEMUIOVector qiov;
struct iovec iov;
iov = (struct iovec) {
.iov_base = buf,
.iov_len = 0,
};
qemu_iovec_init_external(&qiov, &iov, 1);
return blk_aio_prwv(blk, req, 0, &qiov, blk_aio_ioctl_entry, 0, cb, opaque);
return blk_aio_prwv(blk, req, 0, buf, blk_aio_ioctl_entry, 0, cb, opaque);
}
int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes)
@ -1949,7 +1946,9 @@ int blk_truncate(BlockBackend *blk, int64_t offset, PreallocMode prealloc,
static void blk_pdiscard_entry(void *opaque)
{
BlkRwCo *rwco = opaque;
rwco->ret = blk_co_pdiscard(rwco->blk, rwco->offset, rwco->qiov->size);
QEMUIOVector *qiov = rwco->iobuf;
rwco->ret = blk_co_pdiscard(rwco->blk, rwco->offset, qiov->size);
}
int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes)

16
cpus.c
View File

@ -993,7 +993,7 @@ void cpu_synchronize_all_pre_loadvm(void)
}
}
static int do_vm_stop(RunState state)
static int do_vm_stop(RunState state, bool send_stop)
{
int ret = 0;
@ -1002,7 +1002,9 @@ static int do_vm_stop(RunState state)
pause_all_vcpus();
runstate_set(state);
vm_state_notify(0, state);
qapi_event_send_stop(&error_abort);
if (send_stop) {
qapi_event_send_stop(&error_abort);
}
}
bdrv_drain_all();
@ -1012,6 +1014,14 @@ static int do_vm_stop(RunState state)
return ret;
}
/* Special vm_stop() variant for terminating the process. Historically clients
* did not expect a QMP STOP event and so we need to retain compatibility.
*/
int vm_shutdown(void)
{
return do_vm_stop(RUN_STATE_SHUTDOWN, false);
}
static bool cpu_can_run(CPUState *cpu)
{
if (cpu->stop) {
@ -1994,7 +2004,7 @@ int vm_stop(RunState state)
return 0;
}
return do_vm_stop(state);
return do_vm_stop(state, true);
}
/**

View File

@ -34,6 +34,7 @@ struct VirtIOBlockDataPlane {
VirtIODevice *vdev;
QEMUBH *bh; /* bh for guest notification */
unsigned long *batch_notify_vqs;
bool batch_notifications;
/* Note that these EventNotifiers are assigned by value. This is
* fine as long as you do not call event_notifier_cleanup on them
@ -47,8 +48,12 @@ struct VirtIOBlockDataPlane {
/* Raise an interrupt to signal guest, if necessary */
void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s, VirtQueue *vq)
{
set_bit(virtio_get_queue_index(vq), s->batch_notify_vqs);
qemu_bh_schedule(s->bh);
if (s->batch_notifications) {
set_bit(virtio_get_queue_index(vq), s->batch_notify_vqs);
qemu_bh_schedule(s->bh);
} else {
virtio_notify_irqfd(s->vdev, vq);
}
}
static void notify_guest_bh(void *opaque)
@ -177,6 +182,12 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev)
s->starting = true;
if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
s->batch_notifications = true;
} else {
s->batch_notifications = false;
}
/* Set up guest notifier (irq) */
r = k->set_guest_notifiers(qbus->parent, nvqs, true);
if (r != 0) {
@ -229,6 +240,22 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev)
return -ENOSYS;
}
/* Stop notifications for new requests from guest.
*
* Context: BH in IOThread
*/
static void virtio_blk_data_plane_stop_bh(void *opaque)
{
VirtIOBlockDataPlane *s = opaque;
unsigned i;
for (i = 0; i < s->conf->num_queues; i++) {
VirtQueue *vq = virtio_get_queue(s->vdev, i);
virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, NULL);
}
}
/* Context: QEMU global mutex held */
void virtio_blk_data_plane_stop(VirtIODevice *vdev)
{
@ -253,13 +280,7 @@ void virtio_blk_data_plane_stop(VirtIODevice *vdev)
trace_virtio_blk_data_plane_stop(s);
aio_context_acquire(s->ctx);
/* Stop notifications for new requests from guest */
for (i = 0; i < nvqs; i++) {
VirtQueue *vq = virtio_get_queue(s->vdev, i);
virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, NULL);
}
aio_wait_bh_oneshot(s->ctx, virtio_blk_data_plane_stop_bh, s);
/* Drain and switch bs back to the QEMU main loop */
blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());

View File

@ -107,9 +107,10 @@ static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n,
return 0;
}
/* assumes s->ctx held */
static void virtio_scsi_clear_aio(VirtIOSCSI *s)
/* Context: BH in IOThread */
static void virtio_scsi_dataplane_stop_bh(void *opaque)
{
VirtIOSCSI *s = opaque;
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
int i;
@ -171,7 +172,7 @@ int virtio_scsi_dataplane_start(VirtIODevice *vdev)
return 0;
fail_vrings:
virtio_scsi_clear_aio(s);
aio_wait_bh_oneshot(s->ctx, virtio_scsi_dataplane_stop_bh, s);
aio_context_release(s->ctx);
for (i = 0; i < vs->conf.num_queues + 2; i++) {
virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
@ -207,7 +208,7 @@ void virtio_scsi_dataplane_stop(VirtIODevice *vdev)
s->dataplane_stopping = true;
aio_context_acquire(s->ctx);
virtio_scsi_clear_aio(s);
aio_wait_bh_oneshot(s->ctx, virtio_scsi_dataplane_stop_bh, s);
aio_context_release(s->ctx);
blk_drain_all(); /* ensure there are no in-flight requests */

View File

@ -113,4 +113,17 @@ typedef struct {
*/
void aio_wait_kick(AioWait *wait);
/**
* aio_wait_bh_oneshot:
* @ctx: the aio context
* @cb: the BH callback function
* @opaque: user data for the BH callback function
*
* Run a BH in @ctx and wait for it to complete.
*
* Must be called from the main loop thread with @ctx acquired exactly once.
* Note that main loop event processing may occur.
*/
void aio_wait_bh_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque);
#endif /* QEMU_AIO_WAIT */

View File

@ -45,7 +45,6 @@ typedef struct {
char *iothread_get_id(IOThread *iothread);
IOThread *iothread_by_id(const char *id);
AioContext *iothread_get_aio_context(IOThread *iothread);
void iothread_stop_all(void);
GMainContext *iothread_get_g_main_context(IOThread *iothread);
/*

View File

@ -56,6 +56,7 @@ void vm_start(void);
int vm_prepare_start(void);
int vm_stop(RunState state);
int vm_stop_force_state(RunState state);
int vm_shutdown(void);
typedef enum WakeupReason {
/* Always keep QEMU_WAKEUP_REASON_NONE = 0 */

View File

@ -101,18 +101,6 @@ void iothread_stop(IOThread *iothread)
qemu_thread_join(&iothread->thread);
}
static int iothread_stop_iter(Object *object, void *opaque)
{
IOThread *iothread;
iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
if (!iothread) {
return 0;
}
iothread_stop(iothread);
return 0;
}
static void iothread_instance_init(Object *obj)
{
IOThread *iothread = IOTHREAD(obj);
@ -333,25 +321,6 @@ IOThreadInfoList *qmp_query_iothreads(Error **errp)
return head;
}
void iothread_stop_all(void)
{
Object *container = object_get_objects_root();
BlockDriverState *bs;
BdrvNextIterator it;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *ctx = bdrv_get_aio_context(bs);
if (ctx == qemu_get_aio_context()) {
continue;
}
aio_context_acquire(ctx);
bdrv_set_aio_context(bs, qemu_get_aio_context());
aio_context_release(ctx);
}
object_child_foreach(container, iothread_stop_iter, NULL);
}
static gpointer iothread_g_main_context_init(gpointer opaque)
{
AioContext *ctx;

View File

@ -38,3 +38,34 @@ void aio_wait_kick(AioWait *wait)
aio_bh_schedule_oneshot(qemu_get_aio_context(), dummy_bh_cb, NULL);
}
}
typedef struct {
AioWait wait;
bool done;
QEMUBHFunc *cb;
void *opaque;
} AioWaitBHData;
/* Context: BH in IOThread */
static void aio_wait_bh(void *opaque)
{
AioWaitBHData *data = opaque;
data->cb(data->opaque);
data->done = true;
aio_wait_kick(&data->wait);
}
void aio_wait_bh_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
{
AioWaitBHData data = {
.cb = cb,
.opaque = opaque,
};
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
aio_bh_schedule_oneshot(ctx, aio_wait_bh, &data);
AIO_WAIT_WHILE(&data.wait, ctx, !data.done);
}

13
vl.c
View File

@ -4722,17 +4722,10 @@ int main(int argc, char **argv, char **envp)
os_setup_post();
main_loop();
replay_disable_events();
/* The ordering of the following is delicate. Stop vcpus to prevent new
* I/O requests being queued by the guest. Then stop IOThreads (this
* includes a drain operation and completes all request processing). At
* this point emulated devices are still associated with their IOThreads
* (if any) but no longer have any work to do. Only then can we close
* block devices safely because we know there is no more I/O coming.
*/
pause_all_vcpus();
iothread_stop_all();
/* No more vcpu or device emulation activity beyond this point */
vm_shutdown();
bdrv_close_all();
res_free();