[PATCH v5 5/7] xenstored: send an evtchn notification on introduce_domain

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

From: Luca Miccio <lucmiccio@xxxxxxxxx>

When xs_introduce_domain is called, send out a notification on the
xenstore event channel so that any (dom0less) domain waiting for the
xenstore interface to be ready can continue with the initialization.
Before sending the notification, clear XS_CONNECTION_STATE_RECONNECTING.

The extra notification is harmless for domains that don't require it.

Signed-off-by: Luca Miccio <lucmiccio@xxxxxxxxx>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
CC: Juergen Gross <jgross@xxxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
---
I dropped the Reviewed-by tags due to the connect = 0 change. Julien
also suggested it would be a good idea to add a clarification statement
about the usage of XS_CONNECTION_STATE_RECONNECTING in the header files
but I wasn't sure what to write. Please advise and I am happy to include
a statement in the next version.

Changes in v5:
- reset XS_CONNECTION_STATE_RECONNECTING before notifying the domU

Changes in v2:
- drop the new late_init parameter
---
 tools/xenstore/xenstored_domain.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/xenstore/xenstored_domain.c 
b/tools/xenstore/xenstored_domain.c
index ae065fcbee..7bb8c64d33 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -493,6 +493,10 @@ static struct domain *introduce_domain(const void *ctx,
                /* Now domain belongs to its connection. */
                talloc_steal(domain->conn, domain);
 
+               /* Notify the domain that xenstore is available */
+               interface->connection = 0x0;
+               xenevtchn_notify(xce_handle, domain->port);
+
                if (!is_master_domain && !restore)
                        fire_watches(NULL, ctx, "@introduceDomain", NULL,
                                     false, NULL);
-- 
2.25.1