[Midnightbsd-cvs] [MidnightBSD/src] e464b0: Grant mapping operations often occur in batch hype...

[Lucas Holt]

  Branch: refs/heads/master
  Home:   https://github.com/MidnightBSD/src
  Commit: e464b0f0af7e6bddd57a9e195ebe3fd54b51f8a1
      https://github.com/MidnightBSD/src/commit/e464b0f0af7e6bddd57a9e195ebe3fd54b51f8a1
  Author: Lucas Holt <luke at foolishgames.com>
  Date:   2021-02-24 (Wed, 24 Feb 2021)

  Changed paths:
    M sys/dev/xen/blkback/blkback.c

  Log Message:
  -----------
  Grant mapping operations often occur in batch hypercalls, where a number of
operations are done in a single hypercall, the success or failure of each one
reported to the backend driver, and the backend driver then loops over the
results, performing follow-up actions based on the success or failure of each
operation.

Unfortunately, when running in HVM/PVH mode, the BSD backend drivers
mishandle this: Some errors are ignored, effectively implying their success
from the success of related batch elements.  In other cases, errors resulting
from one batch element lead to further batch elements not being inspected,
and hence successful ones to not be possible to properly unmap upon error
recovery.

Obtained from: FreeBSD


  Commit: b0699e38c76746af38861ed7493a4c7fe595cc58
      https://github.com/MidnightBSD/src/commit/b0699e38c76746af38861ed7493a4c7fe595cc58
  Author: Lucas Holt <luke at foolishgames.com>
  Date:   2021-02-24 (Wed, 24 Feb 2021)

  Changed paths:
    M UPDATING

  Log Message:
  -----------
  Document xen fix


Compare: https://github.com/MidnightBSD/src/compare/b0a80227d786...b0699e38c767