In case Xenstore is detecting a malicious ring page modification (e.g.
an invalid producer or consumer index set by a guest) it will ignore
the connection of that guest in future.
Add a new error field to the ring page indicating that case. Add a new
feature bit in order to signal the presence of that error field.
Move the ignore_connection() function to xenstored_domain.c in order
to be able to access the ring page for setting the error indicator.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Hvmloader uses the xenstore ring and then tries to reset it back
to its initial state before booting the guest. Occasionally xenstored
will read the ring while it is being zeroed and conclude it has
been corrupted. This prevents PV drivers from loading in the guest.
This patch updates the xenstore ring protocol definition, enabling
a server to advertise additional features to the guest. One such feature
is defined: the ability to cleanly reset the ring including the
higher-level protocol, like an enhanced RESET_WATCHES for rings.
This patch implements the ring reconnection features in oxenstored
and hvmloader, fixing the bug.
This patch also defines an 'invalid' xenstore packet type and uses this
to poison the ring over a reconnect. This will make diagnosing this
bug much easier in future.
Signed-off-by: David Scott <dave.scott@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Jon Ludlam <jonathan.ludlam@citrix.com>
Juergen Gross
David Scott