Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20180822-1' into staging

migration/next for 20180822

# gpg: Signature made Wed 22 Aug 2018 12:07:59 BST
# gpg:                using RSA key F487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* remotes/juanquintela/tags/migration/20180822-1:
  migration: hold the lock only if it is really needed
  migration: move handle of zero page to the thread
  migration: drop the return value of do_compress_ram_page
  migration: introduce save_zero_page_to_file
  migration: fix counting normal page for compression
  migration: do not wait for free thread
  migration: poll the cm event for destination qemu
  tests/migration-test: Silence the kvm_hv message by default
  migration: implement the shutdown for RDMA QIOChannel
  migration: poll the cm event while wait RDMA work request completion
  migration: invoke qio_channel_yield only when qemu_in_coroutine()
  migration: implement io_set_aio_fd_handler function for RDMA QIOChannel
  migration: Stop rdma yielding during incoming postcopy
  migration: implement bi-directional RDMA QIOChannel
  migration: create a dedicated connection for rdma return path
  migration: disable RDMA WRITE after postcopy started
  migrate/cpu-throttle: Add max-cpu-throttle migration parameter
  docs/migration: Clarify pre_load in subsections
  migration: Correctly handle subsections with no 'needed' function
  qapi/migration.json: fix the description for "query-migrate" output

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
index 6ed3fce061..687570754d 100644
--- a/docs/devel/migration.rst
+++ b/docs/devel/migration.rst
@@ -240,10 +240,13 @@ should succeed even with the data missing.  To support this the
 subsection can be connected to a device property and from there
 to a versioned machine type.
 
-One important note is that the post_load() function is called "after"
-loading all subsections, because a newer subsection could change same
-value that it uses.  A flag, and the combination of pre_load and post_load
-can be used to detect whether a subsection was loaded, and to
+The 'pre_load' and 'post_load' functions on subsections are only
+called if the subsection is loaded.
+
+One important note is that the outer post_load() function is called "after"
+loading all subsections, because a newer subsection could change the same
+value that it uses.  A flag, and the combination of outer pre_load and
+post_load can be used to detect whether a subsection was loaded, and to
 fall back on default behaviour when the subsection isn't present.
 
 Example:
@@ -315,8 +318,8 @@ For example:
       the property to false.
    c) Add a static bool  support_foo function that tests the property.
    d) Add a subsection with a .needed set to the support_foo function
-   e) (potentially) Add a pre_load that sets up a default value for 'foo'
-      to be used if the subsection isn't loaded.
+   e) (potentially) Add an outer pre_load that sets up a default value
+      for 'foo' to be used if the subsection isn't loaded.
 
 Now that subsection will not be generated when using an older
 machine type and the migration stream will be accepted by older