The condition: if there is a space in the ring then wait for the producer
to fill the ring also evaluates to true even if the ring if full. It
leads to a deadlock where producer is waiting for consumer
to consume the items and consumer is waiting for producer to fill the ring.
Fix for the issue: check if the ring is full and then break from
the loop to consume the items from the ring.
eg. case: prod = 1272, cons = 248.
Signed-off-by: Anshul Makkar <anshul.makkar@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Julien Grall <julien.grall@arm.com>
hvmloader is unhosted, and shouldn't use the system errno.h. It already has
to use Xen's errno.h for other hypercalls. The use of public/io/xs_wire.h
requires the use of un-prefixed errno values.
This fixes the build on stricter toolchains where requesting -fno-builtin does
reduce the include path as much as it can.
Reported-by: Doug Goldstein <cardoe@cardoe.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Doug Goldstein <cardoe@cardoe.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Consume and ignore all XS_DEBUG packets, and pass the response type back to
the caller of xenbus_recv() so the caller can take appropriate action if an
unexpected reply was received.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
The functions ring_read and ring_write() have logic to try and deal with
partial reads and writes.
However, in all cases where the "while (len)" loop executed twice, data
corruption would occur as the second memcpy() starts from the beginning of
"data" again, rather than from where it got to.
This bug manifested itself as protocol corruption when a reply header crossed
the first wrap of the response ring. However, similar corruption would also
occur if hvmloader observed xenstored performing partial writes of the block
in question, or if hvmloader had to wait for xenstored to make space in either
ring.
Reported-by: Adam Kucia <djexit@o2.pl>
Signed-off-by: Andrew Cooper <andrew.cooper3@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>
The emacs variable to set the C style from a local variable block is
c-file-style, not c-set-style.
Signed-off-by: David Vrabel <david.vrabel@citrix.com
These fields need to be valid at all times. Hypervisor ensures this
even across 32/64-bit guest transitions.
This fixes a bug where wallclock time is incorrect for booting 32-bit
HVM guests.
This should be backported to Xen 4.1 and 4.2.
Signed-off-by: Keir Fraser <keir@xen.org>
Tested-and-Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
liberal terms.
This code is a great example of a simple xenbus implementation and we
would like to reuse it in projects with non-GPLv2 license
(specifically in this case SeaBIOS which is GPLv3).
I picked the license from extras/mini-os/COPYING (A two clause BSD
style license) since mini-os exists for much the same purpose.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
Anshul Makkar
Andrew Cooper
David Scott
David Vrabel
Keir Fraser
Paul Durrant
Ian Campbell
Keir Fraser