[PATCH v10 0/10] xenguest optimisations

[Frediano Ziglio <freddy77@xxxxxxxxx>]

Reduce number of allocations sending memory state.

Implement and use new Xen and Linux kernel ABI to copy foreign memory.
This new ABI allows to replace the expensive  map/copy/unmap sequence
with a single call.

Changes since v1:
- add commit to cache up to 4 pages in hypercall;
- add other 2 commits reducing chunks passed to write/writev.

Changes since v2:
- update patches commit prefixes;
- add other 2 optisations.

Changes since v3:
- address some comments;
- add patches for foreign copy optimisation.

Changes since v4:
- added Reviewed-by;
- improved commit messages;
- other minor fixes, see individual commits.

Changes since v5:
- avoids potential buffer underflow if nr_pages is 0 calling cache_alloc;
- do not overwrite errno if xenforeignmemory_map fails;
- lot of changes to "implement new foreign copy hypercall", see specific
  commit.

Changes since v6:
- removed merged patch;
- keep only optimization commits for now;
- improve comments;
- merged "fill directly iov structure collapsing them" and moved it;
- split "allocate various migration arrays just once";
- add a commit for memory checks using Valgrind.

Changes since v7:
- removed merged commits;
- minor style fixes.

Changes since v8:
- added Reviewed-by;
- remove useless check;
- remove useless memset;
- initialize variables while declaring them.

Changes since v9:
- add back commits for foreign copy;
- rework page permissions check;
- do not limit domain for new hypercall;
- add back some memory check using Valgrind and sanitizers;
- fixed compatibility for ARM;
- minor fixes.

Edwin Török (3):
  libs/call: cache up to 4 pages in hypercall bounce buffers
  libs/guest: allocate various migration arrays just once
  libs/guest: use foreign copy API during migration

Frediano Ziglio (6):
  libs/guest: move batch_pfns into a separate structure
  libs/guest: use Valgrind or sanitizers to detect various buffer
    overflows
  libs/guest: add xg_foreignmemory_copy_{from,to}
  xen: implement new foreign copy hypercall
  privcmd: Add definition for new Linux privcmd to access new Xen
    hypercall
  libs/guest: use new hypercall if available

 tools/config.h.in                     |   6 ++
 tools/configure                       |  12 +++
 tools/configure.ac                    |   3 +-
 tools/include/xen-sys/Linux/privcmd.h |  10 ++
 tools/libs/call/buffer.c              |  34 ++++--
 tools/libs/call/core.c                |   3 +-
 tools/libs/call/private.h             |   8 +-
 tools/libs/ctrl/xc_private.h          |  61 ++++++++++-
 tools/libs/guest/xg_sr_common.c       |  86 +++++++++++++++
 tools/libs/guest/xg_sr_common.h       |  25 ++++-
 tools/libs/guest/xg_sr_restore.c      |  78 +++++++-------
 tools/libs/guest/xg_sr_save.c         | 134 +++++++++++------------
 xen/common/memory.c                   | 149 ++++++++++++++++++++++++++
 xen/include/public/memory.h           |  45 +++++++-
 xen/include/xsm/dummy.h               |  14 +++
 xen/include/xsm/hooks.h               |   2 +
 xen/xsm/flask/hooks.c                 |  10 ++
 17 files changed, 552 insertions(+), 128 deletions(-)

-- 
2.43.0