[PATCH 0/4] Add "xl info" command

[Andre Przywara <andre.przywara@amd.com>]

Hi,

as already mentioned in previous emails, the "info" subcommand is 
missing from the xl tool.
The attached patchset adds support for this, extending libxl on the way 
to provide the necessary info only by using own functions.
On my system the output of xm info and xl info was identical, I omitted 
the recent NUMA additions from xl info for now and will provide the
necessary patches later.

Most of the additions are straightforward, just some words on 
libxl_get_version_info():
The xen_version hypercall uses statically allocated memory for passing 
strings (e.g. 1024 Bytes for commandline). To gather all information, 
one has to hypercall multiple times with different arg values, each 
information also has a different (static) result type.
To make this more user friendly in libxl, I created a structure holding 
all information in dynamically allocated pointers. These will be 
malloced and filled on calling libxl_get_version_info() and have to be 
freed by the caller (with libxl_free_version_info()).
To avoid doing several hypercalls and copying unnecessary memory, I used 
a bitmask to select the pieces of information the caller is interested. 
This is especially useful if one wants to know the Xen version or the 
PAGESIZE only. For xl info there is a LIBXL_VERSION_ALL_MASK to get all 
of them.

Please apply!

Regards,
Andre.

-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
Tel: +49 351 488-3567-12