On Fri, Aug 21, 2009 at 12:53:49PM +0300, Avi Kivity wrote:
+ * Queue size (per-device).
+ *
+ * XXX: eventually we need to communicate this to the guest and/or make it
+ * tunable by the guest. If we get more outstanding requests at a
time
+ * than this we will get EAGAIN from io_submit which is communicated
to
+ * the guest as an I/O error.
+ */
+#define MAX_EVENTS 128
Or, we could queue any extra requests.
That doesn't make much sense. We'd just do an additional level of
queueing in addition to those already optimized implementation in the
guest and host kernels. This is really just an issue of communicating
the limits we have and deal with it efficiently. It should be a
relatively small add-on patch.