int event_notifier_wait_and_clear(EventNotifier *e, long second)
{
fd_set rfds;
int value;
struct timeval tv;
struct timeval *tvp;
if (second != 0) {
tv.tv_sec = second;
tv.tv_usec = 0;
tvp = &tv;
} else {
tvp = NULL;
}
FD_ZERO(&rfds);
FD_SET(e->rfd, &rfds);
value = select(e->rfd + 1, &rfds, NULL, NULL, tvp);
switch (value) {
case -1:
value = -errno;
break;
case 1:
event_notifier_test_and_clear(e);
break;
case 0:
default:
value = 0;
break;
}
return value;
}
static void qemu_laio_completion_cb(EventNotifier *e)
{
struct qemu_laio_state *s = container_of(e, struct qemu_laio_state, e);
if (event_notifier_test_and_clear(&s->e)) {
qemu_bh_schedule(s->completion_bh);
}
}
static void kvm_hv_sint_ack_handler(EventNotifier *notifier)
{
HvSintRoute *sint_route = container_of(notifier, HvSintRoute,
sint_ack_notifier);
event_notifier_test_and_clear(notifier);
if (sint_route->sint_ack_clb) {
sint_route->sint_ack_clb(sint_route);
}
}
static void v9fs_qemu_process_req_done(EventNotifier *e)
{
Coroutine *co;
event_notifier_test_and_clear(e);
while ((co = g_async_queue_try_pop(v9fs_pool.completed)) != NULL) {
qemu_coroutine_enter(co, NULL);
}
}
static void event_ready_cb(EventNotifier *e)
{
EventNotifierTestData *data = container_of(e, EventNotifierTestData, e);
g_assert(event_notifier_test_and_clear(e));
data->n++;
if (data->active > 0) {
data->active--;
}
if (data->auto_set && data->active) {
event_notifier_set(e);
}
}
static void win32_aio_completion_cb(EventNotifier *e)
{
QEMUWin32AIOState *s = container_of(e, QEMUWin32AIOState, e);
DWORD count;
ULONG_PTR key;
OVERLAPPED *ov;
event_notifier_test_and_clear(&s->e);
while (GetQueuedCompletionStatus(s->hIOCP, &count, &key, &ov, 0)) {
QEMUWin32AIOCB *waiocb = container_of(ov, QEMUWin32AIOCB, ov);
win32_aio_process_completion(s, waiocb, count);
}
}
static int pci_testdev_start(IOTest *test)
{
test->hdr->count = 0;
if (!test->hasnotifier) {
return 0;
}
event_notifier_test_and_clear(&test->notifier);
memory_region_add_eventfd(test->mr,
le32_to_cpu(test->hdr->offset),
test->size,
test->match_data,
test->hdr->data,
&test->notifier);
return 0;
}
static void handle_notify(EventNotifier *e)
{
VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
host_notifier);
VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
event_notifier_test_and_clear(&s->host_notifier);
blk_io_plug(s->conf->conf.blk);
for (;;) {
MultiReqBuffer mrb = {};
int ret;
/* Disable guest->host notifies to avoid unnecessary vmexits */
vring_disable_notification(s->vdev, &s->vring);
for (;;) {
VirtIOBlockReq *req = virtio_blk_alloc_request(vblk);
ret = vring_pop(s->vdev, &s->vring, &req->elem);
if (ret < 0) {
virtio_blk_free_request(req);
break; /* no more requests */
}
trace_virtio_blk_data_plane_process_request(s, req->elem.out_num,
req->elem.in_num,
req->elem.index);
virtio_blk_handle_request(req, &mrb);
}
if (mrb.num_reqs) {
virtio_blk_submit_multireq(s->conf->conf.blk, &mrb);
}
if (likely(ret == -EAGAIN)) { /* vring emptied */
/* Re-enable guest->host notifies and stop processing the vring.
* But if the guest has snuck in more descriptors, keep processing.
*/
if (vring_enable_notification(s->vdev, &s->vring)) {
break;
}
} else { /* fatal error */
break;
}
}
blk_io_unplug(s->conf->conf.blk);
}
static uint64_t
pci_testdev_read(void *opaque, hwaddr addr, unsigned size)
{
PCITestDevState *d = opaque;
const char *buf;
IOTest *test;
if (d->current < 0) {
return 0;
}
test = &d->tests[d->current];
buf = (const char *)test->hdr;
if (addr + size >= test->bufsize) {
return 0;
}
if (test->hasnotifier) {
event_notifier_test_and_clear(&test->notifier);
}
return buf[addr];
}
static void ivshmem_vector_notify(void *opaque)
{
MSIVector *entry = opaque;
PCIDevice *pdev = entry->pdev;
IVShmemState *s = IVSHMEM(pdev);
int vector = entry - s->msi_vectors;
EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
if (!event_notifier_test_and_clear(n)) {
return;
}
IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, vector);
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
msix_notify(pdev, vector);
} else {
ivshmem_IntrStatus_write(s, 1);
}
}
static void ivshmem_vector_poll(PCIDevice *dev,
unsigned int vector_start,
unsigned int vector_end)
{
IVShmemState *s = IVSHMEM_COMMON(dev);
unsigned int vector;
IVSHMEM_DPRINTF("vector poll %p %d-%d\n", dev, vector_start, vector_end);
vector_end = MIN(vector_end, s->vectors);
for (vector = vector_start; vector < vector_end; vector++) {
EventNotifier *notifier = &s->peers[s->vm_id].eventfds[vector];
if (!msix_is_masked(dev, vector)) {
continue;
}
if (event_notifier_test_and_clear(notifier)) {
msix_set_pending(dev, vector);
}
}
}
static void qemu_laio_completion_cb(EventNotifier *e)
{
struct qemu_laio_state *s = container_of(e, struct qemu_laio_state, e);
while (event_notifier_test_and_clear(&s->e)) {
struct io_event events[MAX_EVENTS];
struct timespec ts = { 0 };
int nevents, i;
do {
nevents = io_getevents(s->ctx, MAX_EVENTS, MAX_EVENTS, events, &ts);
} while (nevents == -EINTR);
for (i = 0; i < nevents; i++) {
struct iocb *iocb = events[i].obj;
struct qemu_laiocb *laiocb =
container_of(iocb, struct qemu_laiocb, iocb);
laiocb->ret = io_event_ret(&events[i]);
qemu_laio_process_completion(s, laiocb);
}
}
}
static void dummy_notifier_read(EventNotifier *n)
{
event_notifier_test_and_clear(n);
}
static void handle_notify(EventNotifier *e)
{
VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
host_notifier);
VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
event_notifier_test_and_clear(&s->host_notifier);
blk_io_plug(s->conf->conf.blk);
for (;;) {
MultiReqBuffer mrb = {
.num_writes = 0,
};
int ret;
/* Disable guest->host notifies to avoid unnecessary vmexits */
vring_disable_notification(s->vdev, &s->vring);
for (;;) {
VirtIOBlockReq *req = virtio_blk_alloc_request(vblk);
ret = vring_pop(s->vdev, &s->vring, &req->elem);
if (ret < 0) {
virtio_blk_free_request(req);
break; /* no more requests */
}
trace_virtio_blk_data_plane_process_request(s, req->elem.out_num,
req->elem.in_num,
req->elem.index);
virtio_blk_handle_request(req, &mrb);
}
virtio_submit_multiwrite(s->conf->conf.blk, &mrb);
if (likely(ret == -EAGAIN)) { /* vring emptied */
/* Re-enable guest->host notifies and stop processing the vring.
* But if the guest has snuck in more descriptors, keep processing.
*/
if (vring_enable_notification(s->vdev, &s->vring)) {
break;
}
} else { /* fatal error */
break;
}
}
blk_io_unplug(s->conf->conf.blk);
}
/* Context: QEMU global mutex held */
void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
VirtIOBlockDataPlane **dataplane,
Error **errp)
{
VirtIOBlockDataPlane *s;
Error *local_err = NULL;
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
*dataplane = NULL;
if (!conf->data_plane && !conf->iothread) {
return;
}
/* Don't try if transport does not support notifiers. */
if (!k->set_guest_notifiers || !k->set_host_notifier) {
error_setg(errp,
"device is incompatible with x-data-plane "
"(transport does not support notifiers)");
return;
}
/* If dataplane is (re-)enabled while the guest is running there could be
* block jobs that can conflict.
*/
if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE,
&local_err)) {
error_setg(errp, "cannot start dataplane thread: %s",
error_get_pretty(local_err));
error_free(local_err);
return;
}
s = g_new0(VirtIOBlockDataPlane, 1);
s->vdev = vdev;
s->conf = conf;
if (conf->iothread) {
s->iothread = conf->iothread;
object_ref(OBJECT(s->iothread));
} else {
/* Create per-device IOThread if none specified. This is for
* x-data-plane option compatibility. If x-data-plane is removed we
* can drop this.
*/
object_initialize(&s->internal_iothread_obj,
sizeof(s->internal_iothread_obj),
TYPE_IOTHREAD);
user_creatable_complete(OBJECT(&s->internal_iothread_obj), &error_abort);
s->iothread = &s->internal_iothread_obj;
}
s->ctx = iothread_get_aio_context(s->iothread);
s->bh = aio_bh_new(s->ctx, notify_guest_bh, s);
error_setg(&s->blocker, "block device is in use by data plane");
blk_op_block_all(conf->conf.blk, s->blocker);
blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_RESIZE, s->blocker);
blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_DRIVE_DEL, s->blocker);
*dataplane = s;
}
