CAMLprim value stub_eventchn_unmask(value xce, value port)
{
if (xc_evtchn_unmask(_H(xce), Int_val(port)) == -1)
caml_failwith("evtchn unmask failed");
return Val_unit;
}
static int evtchn_suspend(checkpoint_state* s)
{
int rc;
rc = xc_evtchn_notify(s->xce, s->suspend_evtchn);
if (rc < 0) {
snprintf(errbuf, sizeof(errbuf),
"failed to notify suspend event channel: %d", rc);
s->errstr = errbuf;
return -1;
}
do
if (!(rc = pollfd(s, xc_evtchn_fd(s->xce))))
rc = xc_evtchn_pending(s->xce);
while (rc >= 0 && rc != s->suspend_evtchn);
if (rc <= 0)
return -1;
if (xc_evtchn_unmask(s->xce, s->suspend_evtchn) < 0) {
snprintf(errbuf, sizeof(errbuf),
"failed to unmask suspend notification channel: %d", rc);
s->errstr = errbuf;
return -1;
}
return 0;
}
static void wait_for_event(void)
{
int ret;
fd_set inset;
evtchn_port_t port;
struct timeval tv;
int evtchn_fd;
if (xce_handle < 0) {
nanosleep(&opts.poll_sleep, NULL);
return;
}
evtchn_fd = xc_evtchn_fd(xce_handle);
FD_ZERO(&inset);
FD_SET(evtchn_fd, &inset);
tv.tv_sec = 1;
tv.tv_usec = 0;
// tv = millis_to_timespec(&opts.poll_sleep);
ret = select(evtchn_fd+1, &inset, NULL, NULL, &tv);
if ( (ret == 1) && FD_ISSET(evtchn_fd, &inset)) {
if ((port = xc_evtchn_pending(xce_handle)) == -1)
perror("Failed to read from event fd");
// if (port == virq_port)
// printf("got the event I was looking for\r\n");
if (xc_evtchn_unmask(xce_handle, port) == -1)
perror("Failed to write to event fd");
}
}
static int init_evt_cli(struct libxenvchan *ctrl, int domain, xentoollog_logger *logger)
{
evtchn_port_or_error_t port;
ctrl->event = xc_evtchn_open(logger, 0);
if (!ctrl->event)
return -1;
port = xc_evtchn_bind_interdomain(ctrl->event,
domain, ctrl->event_port);
if (port < 0)
goto fail;
ctrl->event_port = port;
if (xc_evtchn_unmask(ctrl->event, ctrl->event_port))
goto fail;
return 0;
fail:
if (port >= 0)
xc_evtchn_unbind(ctrl->event, port);
xc_evtchn_close(ctrl->event);
ctrl->event = NULL;
return -1;
}
static void handle_aio_events(struct fs_mount *mount)
{
int fd, ret, count, i, notify;
evtchn_port_t port;
/* AIO control block for the evtchn file destriptor */
struct aiocb evtchn_cb;
const struct aiocb * cb_list[mount->nr_entries];
int request_ids[mount->nr_entries];
/* Prepare the AIO control block for evtchn */
fd = xc_evtchn_fd(mount->evth);
bzero(&evtchn_cb, sizeof(struct aiocb));
evtchn_cb.aio_fildes = fd;
evtchn_cb.aio_nbytes = sizeof(port);
evtchn_cb.aio_buf = &port;
assert(aio_read(&evtchn_cb) == 0);
wait_again:
/* Create list of active AIO requests */
count = 0;
for(i=0; i<mount->nr_entries; i++)
if(mount->requests[i].active)
{
cb_list[count] = &mount->requests[i].aiocb;
request_ids[count] = i;
count++;
}
/* Add the event channel at the end of the list. Event channel needs to be
* handled last as it exits this function. */
cb_list[count] = &evtchn_cb;
request_ids[count] = -1;
count++;
/* Block till an AIO requset finishes, or we get an event */
while(1) {
int ret = aio_suspend(cb_list, count, NULL);
if (!ret)
break;
assert(errno == EINTR);
}
for(i=0; i<count; i++)
if(aio_error(cb_list[i]) != EINPROGRESS)
{
if(request_ids[i] >= 0)
dispatch_response(mount, request_ids[i]);
else
goto read_event_channel;
}
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&mount->ring, notify);
printf("Pushed responces and notify=%d\n", notify);
if(notify)
xc_evtchn_notify(mount->evth, mount->local_evtchn);
goto wait_again;
read_event_channel:
assert(aio_return(&evtchn_cb) == sizeof(evtchn_port_t));
assert(xc_evtchn_unmask(mount->evth, mount->local_evtchn) >= 0);
}
int libvchan_wait(struct libvchan *ctrl)
{
int ret;
#ifndef CONFIG_STUBDOM
ret = xc_evtchn_pending(ctrl->evfd);
#else
int vchan_fd = libvchan_fd_for_select(ctrl);
fd_set rfds;
libvchan_prepare_to_select(ctrl);
while ((ret = xc_evtchn_pending(ctrl->evfd)) < 0) {
FD_ZERO(&rfds);
FD_SET(0, &rfds);
FD_SET(vchan_fd, &rfds);
ret = select(vchan_fd + 1, &rfds, NULL, NULL, NULL);
if (ret < 0 && errno != EINTR) {
perror("select");
return ret;
}
}
#endif
if (ret!=-1 && xc_evtchn_unmask(ctrl->evfd, ctrl->evport))
return -1;
if (ret!=-1 && libvchan_is_eof(ctrl))
return -1;
return ret;
}
int libxenvchan_wait(struct libxenvchan *ctrl)
{
int ret = xc_evtchn_pending(ctrl->event);
if (ret < 0)
return -1;
xc_evtchn_unmask(ctrl->event, ret);
return 0;
}
CAMLprim value stub_eventchn_unmask(value xce, value _port)
{
CAMLparam2(xce, _port);
evtchn_port_t port;
port = Int_val(_port);
if (xc_evtchn_unmask(_H(xce), port))
caml_failwith("evtchn unmask failed");
CAMLreturn(Val_unit);
}
CAMLprim value stub_eventchn_unmask(value xce, value port)
{
CAMLparam2(xce, port);
if (xc_evtchn_unmask(_H(xce), Int_val(port)) == -1)
{
perror("xc_evtchn_unmask");
caml_failwith(strerror(errno));
}
CAMLreturn(Val_unit);
}
static void xen_be_evtchn_event(void *opaque)
{
struct XenDevice *xendev = opaque;
evtchn_port_t port;
port = xc_evtchn_pending(xendev->evtchndev);
if (port != xendev->local_port) {
xen_be_printf(xendev, 0, "xc_evtchn_pending returned %d (expected %d)\n",
port, xendev->local_port);
return;
}
xc_evtchn_unmask(xendev->evtchndev, port);
if (xendev->ops->event) {
xendev->ops->event(xendev);
}
}
int xc_await_suspend(xc_interface *xch, xc_evtchn *xce, int suspend_evtchn)
{
int rc;
do {
rc = xc_evtchn_pending(xce);
if (rc < 0) {
ERROR("error polling suspend notification channel: %d", rc);
return -1;
}
} while (rc != suspend_evtchn);
/* harmless for one-off suspend */
if (xc_evtchn_unmask(xce, suspend_evtchn) < 0)
ERROR("failed to unmask suspend notification channel: %d", rc);
return 0;
}
static int await_suspend(void)
{
int rc;
do {
rc = xc_evtchn_pending(si.xce);
if (rc < 0) {
warnx("error polling suspend notification channel: %d", rc);
return -1;
}
} while (rc != si.suspend_evtchn);
/* harmless for one-off suspend */
if (xc_evtchn_unmask(si.xce, si.suspend_evtchn) < 0)
warnx("failed to unmask suspend notification channel: %d", rc);
return 0;
}
int libvchan_wait(struct libvchan *ctrl)
{
int ret;
ret = xc_evtchn_pending_with_flush(ctrl->evfd);
// I don't know how to avoid evtchn ring buffer overflow without
// introducing any race condition (in qrexec-agent code). Because of that,
// handle overflow with ring reset - because we just received some events
// (overflow means ring full, so some events was recorded...) the reset
// isn't critical here - always after libvchan_wait we check if there is
// something to read from the vchan
if (ret == -1 && GetLastError() == ERROR_IO_DEVICE)
ret = xc_evtchn_reset(ctrl->evfd);
if (ret!=-1 && xc_evtchn_unmask(ctrl->evfd, ctrl->evport))
return -1;
if (ret!=-1 && libvchan_is_eof(ctrl))
return -1;
return ret;
}
/* Process events from the frontend event channel */
static void xenfb_dispatch_channel(void *opaque)
{
struct xenfb *xenfb = (struct xenfb *)opaque;
evtchn_port_t port;
port = xc_evtchn_pending(xenfb->evt_xch);
if (port == -1) {
xenfb_shutdown(xenfb);
exit(1);
}
if (port == xenfb->fb.port)
xenfb_on_fb_event(xenfb);
else if (port == xenfb->kbd.port)
xenfb_on_kbd_event(xenfb);
if (xc_evtchn_unmask(xenfb->evt_xch, port) == -1) {
xenfb_shutdown(xenfb);
exit(1);
}
}
/*
* XXX only called by tapdisk_xenio_ctx_ring_event
*/
static inline struct td_xenblkif *
xenio_pending_blkif(struct td_xenio_ctx * const ctx)
{
evtchn_port_or_error_t port;
struct td_xenblkif *blkif;
int err;
ASSERT(ctx);
/*
* Get the local port for which there is a pending event.
*/
port = xc_evtchn_pending(ctx->xce_handle);
if (port == -1) {
/* TODO log error */
return NULL;
}
/*
* Find the block interface with that local port.
*/
tapdisk_xenio_ctx_find_blkif(ctx, blkif,
blkif->port == port);
if (blkif) {
err = xc_evtchn_unmask(ctx->xce_handle, port);
if (err) {
/* TODO log error */
return NULL;
}
}
/*
* TODO Is it possible to have an pending event channel but no block
* interface associated with it?
*/
return blkif;
}
/// Unmasks event channel; must be called before calling select(), and only then
void libvchan_prepare_to_select(struct libvchan *ctrl)
{
xc_evtchn_unmask(ctrl->evfd, ctrl->evport);
}