Merge remote-tracking branch 'remotes/ehabkost-gl/tags/machine-next-pull-request...

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

Machine queue, 2021-02-02

Feature:
* nvdimm: read-only file support (Stefan Hajnoczi)

# gpg: Signature made Tue 02 Feb 2021 19:27:21 GMT
# gpg:                using RSA key 5A322FD5ABC4D3DBACCFD1AA2807936F984DC5A6
# gpg:                issuer "ehabkost@redhat.com"
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost-gl/tags/machine-next-pull-request:
  nvdimm: check -object memory-backend-file, readonly=on option
  hostmem-file: add readonly=on|off option
  memory: add readonly support to memory_region_init_ram_from_file()

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