xenstore: block signals in watch wakeup thread

The thread created to wakeup watchers is not intended to handle signals
(and a later patch will reduce it's stack size which makes it unsuitable
for doing so).

Signed-off-by: Simon Rowe <simon.rowe@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
xenstore: set read_thread stacksize

xs_watch() creates a thread to wake watchers using default attributes. The
stacksize can be quite large (8 MB on Linux), applications that link against
xenstore end up having a larger memory footprint than necessary.

Signed-off-by: Simon Rowe <simon.rowe@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
libxl: remove libxl__error_set prototype

The implementation went away in 25181:26f72d923cb9 "libxl: Crash (more
sensibly) on malloc failure".

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
xend: do not run a hotplug script from qemu on Linux

The current vif-hotplug-common.sh for renaming the tap device is failing
because it is racing with this script and therefore the device is unexpectedly
up when we come to rename it.

Fix this in the same way as libxl does, by disabling the script (only on
Linux).

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
tools: pass EXTRA_CFLAGS via environment

Currently qemu-xen will be compiled with CFLAGS only if CFLAGS was
already in the environment during make invocation. If CFLAGS is in
environment then make will append all of the various flags specified in
xen Makefiles to this environment variable, which is then used in qemu
configure. Since qemu-xen is not ready for compiler flags like
"-std=gnu99" compilation will fail. If CFLAGS is not in environment,
then configure will use just its own "-O2 -g" because make does not
export its own CFLAGS variable.

>From a distro perspective, it is required to build libraries and
binaries with certain global cflags (arbitrary gcc options). Up to the
point when qemu-xen was imported it worked as expected by exporting
CFLAGS before 'make tools'.  Now qemu-upstream reuses these CFLAGS, but
it cant deal with the result.

This patch extends the tools Makefiles so that three new environment
variables are recognized:
  EXTRA_CFLAGS_XEN_TOOLS= specifies CFLAGS for the tools build.
  EXTRA_CFLAGS_QEMU_TRADITIONAL= specifies CFLAGS for old qemu.
  EXTRA_CFLAGS_QEMU_XEN= specifies CFLAGS for new qemu.

Special care needs to be taken in tools/firmware because the resulting
binaries are not linked with the hosts runtime libraries. These binaries
run in guest context. To avoid build errors from gcc options like
-fstack-protector, reuse existing practice to unset the new
EXTRA_CFLAGS_XEN_TOOLS for the firmware dirs.


The new feature can be used like this in a rpm xen.spec file:

   export EXTRA_CFLAGS_XEN_TOOLS="${RPM_OPT_FLAGS}"
   export EXTRA_CFLAGS_QEMU_TRADITIONAL="${RPM_OPT_FLAGS}"
   export EXTRA_CFLAGS_QEMU_XEN="${RPM_OPT_FLAGS}"
   ./configure \
   	--libdir=%{_libdir} \
   	--prefix=/usr
   make


   Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
QEMU_TAG update
tools: do not install qemu if just doing a build

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
QEMU_TAG update