Merge remote-tracking branch 'remotes/ehabkost/tags/machine-next-pull-request' into staging

Machine/CPU/NUMA queue, 2017-09-19

# gpg: Signature made Tue 19 Sep 2017 21:17:01 BST
# gpg:                using RSA key 0x2807936F984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>"
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/machine-next-pull-request:
  MAINTAINERS: Update git URLs for my trees
  hw/acpi-build: Fix SRAT memory building in case of node 0 without RAM
  NUMA: Replace MAX_NODES with nb_numa_nodes in for loop
  numa: cpu: calculate/set default node-ids after all -numa CLI options are parsed
  arm: drop intermediate cpu_model -> cpu type parsing and use cpu type directly
  pc: use generic cpu_model parsing
  vl.c: convert cpu_model to cpu type and set of global properties before machine_init()
  cpu: make cpu_generic_init() abort QEMU on error
  qom: cpus: split cpu_generic_init() on feature parsing and cpu creation parts
  hostmem-file: Add "discard-data" option
  osdep: Define QEMU_MADV_REMOVE
  vl: Clean up user-creatable objects when exiting

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

1 files changed, 7 insertions, 1 deletions

diff --git a/qemu-options.hx b/qemu-options.hx
index 600614f6e5..77859a248c 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4182,7 +4182,7 @@ property must be set.  These objects are placed in the
 
 @table @option
 
-@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off}
+@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off}
 
 Creates a memory file backend object, which can be used to back
 the guest RAM with huge pages. The @option{id} parameter is a
@@ -4194,6 +4194,12 @@ the path to either a shared memory or huge page filesystem mount.
 The @option{share} boolean option determines whether the memory
 region is marked as private to QEMU, or shared. The latter allows
 a co-operating external process to access the QEMU memory region.
+Setting the @option{discard-data} boolean option to @var{on}
+indicates that file contents can be destroyed when QEMU exits,
+to avoid unnecessarily flushing data to the backing file.  Note
+that @option{discard-data} is only an optimization, and QEMU
+might not discard file contents if it aborts unexpectedly or is
+terminated using SIGKILL.
 
 @item -object rng-random,id=@var{id},filename=@var{/dev/random}