From 345f42b4be9f9975ff3f7f3e95acae4f67c74f89 Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Mon, 8 Apr 2019 16:16:17 +0100 Subject: xen-bus / xen-block: add support for event channel polling This patch introduces a poll callback for event channel fd-s and uses this to invoke the channel callback function. To properly support polling, it is necessary for the event channel callback function to return a boolean saying whether it has done any useful work or not. Thus xen_block_dataplane_event() is modified to directly invoke xen_block_handle_requests() and the latter only returns true if it actually processes any requests. This also means that the call to qemu_bh_schedule() is moved into xen_block_complete_aio(), which is more intuitive since the only reason for doing a deferred poll of the shared ring should be because there were previously insufficient resources to fully complete a previous poll. Signed-off-by: Paul Durrant Reviewed-by: Anthony PERARD Message-Id: <20190408151617.13025-4-paul.durrant@citrix.com> Signed-off-by: Anthony PERARD --- hw/xen/xen-bus.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'hw/xen') diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index 2210526..7503eea 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -932,13 +932,20 @@ struct XenEventChannel { void *opaque; }; +static bool xen_device_poll(void *opaque) +{ + XenEventChannel *channel = opaque; + + return channel->handler(channel->opaque); +} + static void xen_device_event(void *opaque) { XenEventChannel *channel = opaque; unsigned long port = xenevtchn_pending(channel->xeh); if (port == channel->local_port) { - channel->handler(channel->opaque); + xen_device_poll(channel); xenevtchn_unmask(channel->xeh, port); } @@ -973,7 +980,7 @@ XenEventChannel *xen_device_bind_event_channel(XenDevice *xendev, channel->ctx = ctx; aio_set_fd_handler(channel->ctx, xenevtchn_fd(channel->xeh), true, - xen_device_event, NULL, NULL, channel); + xen_device_event, NULL, xen_device_poll, channel); QLIST_INSERT_HEAD(&xendev->event_channels, channel, list); -- cgit v1.1