linux/drivers/xen/xenbus
Olaf Hering 254d1a3f02 xen/pv-on-hvm kexec: shutdown watches from old kernel
Add xs_reset_watches function to shutdown watches from old kernel after
kexec boot.  The old kernel does not unregister all watches in the
shutdown path.  They are still active, the double registration can not
be detected by the new kernel.  When the watches fire, unexpected events
will arrive and the xenwatch thread will crash (jumps to NULL).  An
orderly reboot of a hvm guest will destroy the entire guest with all its
resources (including the watches) before it is rebuilt from scratch, so
the missing unregister is not an issue in that case.

With this change the xenstored is instructed to wipe all active watches
for the guest.  However, a patch for xenstored is required so that it
accepts the XS_RESET_WATCHES request from a client (see changeset
23839:42a45baf037d in xen-unstable.hg). Without the patch for xenstored
the registration of watches will fail and some features of a PVonHVM
guest are not available. The guest is still able to boot, but repeated
kexec boots will fail.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-07-19 15:52:02 -04:00
..
Makefile xen: Add xenbus_backend device 2011-12-16 13:29:41 -05:00
xenbus_client.c xenbus: address compiler warnings 2012-02-26 11:04:07 -05:00
xenbus_comms.c xenbus: Add support for xenbus backend in stub domain 2012-05-21 09:53:18 -04:00
xenbus_comms.h xenbus: Add support for xenbus backend in stub domain 2012-05-21 09:53:18 -04:00
xenbus_dev_backend.c xenbus: Add support for xenbus backend in stub domain 2012-05-21 09:53:18 -04:00
xenbus_dev_frontend.c xenbus_dev: add missing error check to watch handling 2012-02-03 16:07:05 -05:00
xenbus_probe.c xenbus: don't free other end details too early 2012-03-13 14:15:29 -04:00
xenbus_probe.h Xen: consolidate and simplify struct xenbus_driver instantiation 2012-01-04 17:01:17 -05:00
xenbus_probe_backend.c Xen: consolidate and simplify struct xenbus_driver instantiation 2012-01-04 17:01:17 -05:00
xenbus_probe_frontend.c xen/xenbus: Add quirk to deal with misconfigured backends. 2012-04-19 12:45:01 -04:00
xenbus_xs.c xen/pv-on-hvm kexec: shutdown watches from old kernel 2012-07-19 15:52:02 -04:00