Machine queue, 2021-02-02

Feature:
 * nvdimm: read-only file support (Stefan Hajnoczi)
 -----BEGIN PGP SIGNATURE-----
 
 iQJIBAABCAAyFiEEWjIv1avE09usz9GqKAeTb5hNxaYFAmAZp5kUHGVoYWJrb3N0
 QHJlZGhhdC5jb20ACgkQKAeTb5hNxaYSeBAAp2lr8eKwsEju6Qpmo+OGo6rG/ORM
 KWRtwwLhHfjj2iFipURAkoepOqmtD/xd7fwItdTwi6zZxzr2eNwKqdlc9T93onzX
 P1yXCNHrz0NmmDB8LbC9Bw2NwubghAYgkuWo+fWMxNU92r+ObnvEc3Otx7P7sGvb
 Lr0yFRANgbJBLw1JTB9kMcWVDhiJ8tMPO9drhUWiMjl4kOaLNyrjUpafNzaleIaO
 GRtIXWts2Waq8wIz3XgSqWDytr075v2vWfvbR4JeAQxFArFbplR3BUuDa8G4nf6O
 nB+DERSMw+fOB2f6ZSYaAqSNwCgIrtwjhkZID0EXzNr03GPuonRnKLRZXYHvlEPT
 0qLaQeeLX+RXr6vGIjPJceQ3PyPlgDMVgVAKPS6Fvx4a3vYzAKfIj6E85QDNhuUJ
 FD37bS3iHpGxMAiuw1Ju1xJdkdzpX11h3nruo8K3sFciMK0CjkfHQKwGcw4XtKE1
 U56PEp+hKmoPe3z9CT1QmlJXlAJ+3NCAAXp6yt5yFDMqU4qxD2ns9+ts/S75o3bo
 P9pTBiaSAlUyOF1a0+0tOMny/7yz+Eb+Dw4CszZ6cCErVC/wNuJXYsF3BCT2roPN
 0d5CKwA717Jh7JmxhSlGXAW4d5mSMn8RHbFnHd5ZKFiIAh4+wnKfXrD9vB+Vq4fr
 Nja+LAk7QoURKjc=
 =TJ6/
 -----END PGP SIGNATURE-----

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>

docs/nvdimm.txt

@@ -17,8 +17,8 @@ following command line options:
 
  -machine pc,nvdimm
  -m $RAM_SIZE,slots=$N,maxmem=$MAX_SIZE
- -object memory-backend-file,id=mem1,share=on,mem-path=$PATH,size=$NVDIMM_SIZE
- -device nvdimm,id=nvdimm1,memdev=mem1
+ -object memory-backend-file,id=mem1,share=on,mem-path=$PATH,size=$NVDIMM_SIZE,readonly=off
+ -device nvdimm,id=nvdimm1,memdev=mem1,unarmed=off
 
 Where,
 
@@ -31,9 +31,10 @@ Where,
    of normal RAM devices and vNVDIMM devices, e.g. $MAX_SIZE should be
    >= $RAM_SIZE + $NVDIMM_SIZE here.
 
- - "object memory-backend-file,id=mem1,share=on,mem-path=$PATH,size=$NVDIMM_SIZE"
-   creates a backend storage of size $NVDIMM_SIZE on a file $PATH. All
-   accesses to the virtual NVDIMM device go to the file $PATH.
+ - "object memory-backend-file,id=mem1,share=on,mem-path=$PATH,
+   size=$NVDIMM_SIZE,readonly=off" creates a backend storage of size
+   $NVDIMM_SIZE on a file $PATH. All accesses to the virtual NVDIMM device go
+   to the file $PATH.
 
    "share=on/off" controls the visibility of guest writes. If
    "share=on", then guest writes will be applied to the backend
@@ -42,8 +43,17 @@ Where,
    "share=off", then guest writes won't be applied to the backend
    file and thus will be invisible to other guests.
 
- - "device nvdimm,id=nvdimm1,memdev=mem1" creates a virtual NVDIMM
-   device whose storage is provided by above memory backend device.
+   "readonly=on/off" controls whether the file $PATH is opened read-only or
+   read/write (default).
+
+ - "device nvdimm,id=nvdimm1,memdev=mem1,unarmed=off" creates a read/write
+   virtual NVDIMM device whose storage is provided by above memory backend
+   device.
+
+   "unarmed" controls the ACPI NFIT NVDIMM Region Mapping Structure "NVDIMM
+   State Flags" Bit 3 indicating that the device is "unarmed" and cannot accept
+   persistent writes. Linux guest drivers set the device to read-only when this
+   bit is present. Set unarmed to on when the memdev has readonly=on.
 
 Multiple vNVDIMM devices can be created if multiple pairs of "-object"
 and "-device" are provided.