The core of a pv linux guest produced via "xl dump-core" is not usable
as since kernel 4.14 only the linear p2m table is kept if Xen indicates
it is supporting that. Unfortunately xc_core_arch_map_p2m() is still
supporting the 3-level p2m tree only.
Fix that by copying the functionality of map_p2m() from libxenguest to
libxenctrl.
Additionally the mapped p2m isn't of a fixed length now, so the
interface to the mapping functions needs to be adapted. In order not to
add even more parameters, expand struct domain_info_context and use a
pointer to that as a parameter.
This is a backport of upstream commit bd7a29c3d0.
As the original patch includes a modification of a data structure
passed via pointer to a library function, the related function in the
library is renamed in order to be able to spot any external users of
that function. Note that it is extremely unlikely any such users
outside the Xen git tree are existing, so the risk to break any
existing programs is very unlikely. In case such a user is existing,
changing the name of xc_map_domain_meminfo() will at least avoid
silent breakage.
Fixes: dc6d609371 ("libxc: set flag for support of linear p2m list in domain builder")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
A guest with memory < maxmem often can't be dumped via xl dump-core
without an error message today:
xc: info: exceeded nr_pages (262144) losing pages
In case the last page of the guest isn't allocated the loop in
xc_domain_dumpcore_via_callback() will always spit out this message,
as the number of already dumped pages is tested before the next page
is checked to be valid.
The guest's p2m_size might be lower than expected, so this should be
tested in order to avoid reading past the end of it.
The guest might use high bits in p2m entries to flag special cases like
foreign mappings. Entries with an MFN larger than the highest MFN of
the host should be skipped.
Signed-off-by: Juergen Gross <jgross@suse.com>
Today tools/libxc needs to be built after tools/libs as libxenctrl is
depending on some libraries in tools/libs. This in turn blocks moving
other libraries depending on libxenctrl below tools/libs.
So carve out libxenctrl from tools/libxc and move it into
tools/libs/ctrl.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> (stubdom parts)
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> (python parts)
Acked-by: Wei Liu <wl@xen.org>
Juergen Gross