[PATCH v9 0/5] Support add/remove memory region and get-max-slots

[pravin.bathija at dell.com]

From: Pravin M Bathija <pravin.bathija at dell.com>

This is version v9 of the patchset and it incorporates the
recommendations made by Stephen Hemminger.

Changes made to patch 3/5
- Restored max_guest_pages initial value to hardcoded 8 instead of
  VHOST_MEMORY_MAX_NREGIONS, matching upstream semantics.

Changes made to patch 4/5
- Added close(reg->fd) and reg->fd = -1 before goto close_msg_fds in the
  mmap failure path to fix fd leak after fd was moved from ctx->fds[0].
- Converted dev_invalidate_vrings from a plain function to a macro +
  implementation function pair, accepting message ID as a parameter so
  the static_assert reports the correct handler at each call site.
- Updated dev_invalidate_vrings call in add_mem_reg to pass
  VHOST_USER_ADD_MEM_REG as message ID.
- Updated dev_invalidate_vrings call in rem_mem_reg to pass
  VHOST_USER_ADD_MEM_REG as message ID.

This implementation has been extensively tested by doing Read/Write I/O
from multiple instances of fio + libblkio (front-end) talking to
spdk/dpdk (back-end) based drives. Tested with qemu front-end talking to
dpdk testpmd (back-end) performing add/removal of memory regions. Also
tested post-copy live migration after doing add_memory_region.

Version Log:
Version v9 (Current version): Incorporate code review suggestions from
Stephen Hemminger as described above.
Version v8:  Incorporate code review suggestions from Stephen Hemminger.
rewrite async_dma_map_region function to iterate guest pages by host
address range matching
change function dev_invalidate_vrings to accept a double pointer to
propagate pointer updates 
new function remove_guest_pages was added
add_mem_reg error path was narrowed to only clean up the single failed
region instead of destroting all existing regions
Version v7: Incorporate code review suggestions from Maxime Coquelin.
Add debug messages to vhost_postcopy_register function.
Version v6: Added the enablement of this feature as a final patch in
this patch-set and other code optimizations as suggested by Maxime
Coquelin.
Version v5: removed the patch that increased the number of memory regions
from 8 to 128. This will be submitted as a separate feature at a later
point after incorporating additional optimizations. Also includes code
optimizations as suggested by Feng Cheng Wen.
Version v4: code optimizations as suggested by Feng Cheng Wen.
Version v3: code optimizations as suggested by Maxime Coquelin
and Thomas Monjalon.
Version v2: code optimizations as suggested by Maxime Coquelin.
Version v1: Initial patch set.

Pravin M Bathija (5):
  vhost: add user to mailmap and define to vhost hdr
  vhost_user: header defines for add/rem mem region
  vhost_user: support function defines for back-end
  vhost_user: Function defs for add/rem mem regions
  vhost_user: enable configure memory slots

 .mailmap               |   1 +
 lib/vhost/rte_vhost.h  |   4 +
 lib/vhost/vhost_user.c | 403 ++++++++++++++++++++++++++++++++++++-----
 lib/vhost/vhost_user.h |  10 +
 4 files changed, 375 insertions(+), 43 deletions(-)

-- 
2.43.0