diff --git a/docs/nvdimm.txt b/docs/nvdimm.txt
index 21249dd0626aea3e49c244e5bfd3e1b0e7d98b53..e903d8bb093b53b8d9ae71c89d529bc33d8db492 100644
--- a/docs/nvdimm.txt
+++ b/docs/nvdimm.txt
@@ -138,3 +138,18 @@ backend of vNVDIMM:
 
  -object memory-backend-file,id=mem1,share=on,mem-path=/dev/dax0.0,size=4G,align=2M
  -device nvdimm,id=nvdimm1,memdev=mem1
+
+Guest Data Persistence
+----------------------
+
+Though QEMU supports multiple types of vNVDIMM backends on Linux,
+currently the only one that can guarantee the guest write persistence
+is the device DAX on the real NVDIMM device (e.g., /dev/dax0.0), to
+which all guest access do not involve any host-side kernel cache.
+
+When using other types of backends, it's suggested to set 'unarmed'
+option of '-device nvdimm' to 'on', which sets the unarmed flag of the
+guest NVDIMM region mapping structure.  This unarmed flag indicates
+guest software that this vNVDIMM device contains a region that cannot
+accept persistent writes. In result, for example, the guest Linux
+NVDIMM driver, marks such vNVDIMM device as read-only.
diff --git a/hw/acpi/nvdimm.c b/hw/acpi/nvdimm.c
index 6ceea196e70ab8d5ef0c5e7750fbc04caeda098c..59d6e4254ccde9d2534d4bee7f31522667f62962 100644
--- a/hw/acpi/nvdimm.c
+++ b/hw/acpi/nvdimm.c
@@ -138,6 +138,8 @@ struct NvdimmNfitMemDev {
 } QEMU_PACKED;
 typedef struct NvdimmNfitMemDev NvdimmNfitMemDev;
 
+#define ACPI_NFIT_MEM_NOT_ARMED     (1 << 3)
+
 /*
  * NVDIMM Control Region Structure
  *
@@ -284,6 +286,7 @@ static void
 nvdimm_build_structure_memdev(GArray *structures, DeviceState *dev)
 {
     NvdimmNfitMemDev *nfit_memdev;
+    NVDIMMDevice *nvdimm = NVDIMM(OBJECT(dev));
     uint64_t size = object_property_get_uint(OBJECT(dev), PC_DIMM_SIZE_PROP,
                                              NULL);
     int slot = object_property_get_int(OBJECT(dev), PC_DIMM_SLOT_PROP,
@@ -312,6 +315,10 @@ nvdimm_build_structure_memdev(GArray *structures, DeviceState *dev)
 
     /* Only one interleave for PMEM. */
     nfit_memdev->interleave_ways = cpu_to_le16(1);
+
+    if (nvdimm->unarmed) {
+        nfit_memdev->flags |= cpu_to_le16(ACPI_NFIT_MEM_NOT_ARMED);
+    }
 }
 
 /*
diff --git a/hw/mem/nvdimm.c b/hw/mem/nvdimm.c
index 618c3d677b06b679e7216ed2a71918560aed35ec..61e677f92ff2d407b01f60d0c95e5ea8db861465 100644
--- a/hw/mem/nvdimm.c
+++ b/hw/mem/nvdimm.c
@@ -25,6 +25,7 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qapi/visitor.h"
+#include "qapi-visit.h"
 #include "hw/mem/nvdimm.h"
 
 static void nvdimm_get_label_size(Object *obj, Visitor *v, const char *name,
@@ -64,11 +65,36 @@ out:
     error_propagate(errp, local_err);
 }
 
+static bool nvdimm_get_unarmed(Object *obj, Error **errp)
+{
+    NVDIMMDevice *nvdimm = NVDIMM(obj);
+
+    return nvdimm->unarmed;
+}
+
+static void nvdimm_set_unarmed(Object *obj, bool value, Error **errp)
+{
+    NVDIMMDevice *nvdimm = NVDIMM(obj);
+    Error *local_err = NULL;
+
+    if (memory_region_size(&nvdimm->nvdimm_mr)) {
+        error_setg(&local_err, "cannot change property value");
+        goto out;
+    }
+
+    nvdimm->unarmed = value;
+
+ out:
+    error_propagate(errp, local_err);
+}
+
 static void nvdimm_init(Object *obj)
 {
     object_property_add(obj, NVDIMM_LABLE_SIZE_PROP, "int",
                         nvdimm_get_label_size, nvdimm_set_label_size, NULL,
                         NULL, NULL);
+    object_property_add_bool(obj, NVDIMM_UNARMED_PROP,
+                             nvdimm_get_unarmed, nvdimm_set_unarmed, NULL);
 }
 
 static MemoryRegion *nvdimm_get_memory_region(PCDIMMDevice *dimm, Error **errp)
diff --git a/include/hw/mem/nvdimm.h b/include/hw/mem/nvdimm.h
index 28e68ddf59c705fb9e54ec4ed46db5619dc51d51..7fd87c4e1cef470e4727b724f359dd5ef1ef3c04 100644
--- a/include/hw/mem/nvdimm.h
+++ b/include/hw/mem/nvdimm.h
@@ -49,6 +49,7 @@
                                                TYPE_NVDIMM)
 
 #define NVDIMM_LABLE_SIZE_PROP "label-size"
+#define NVDIMM_UNARMED_PROP    "unarmed"
 
 struct NVDIMMDevice {
     /* private */
@@ -74,6 +75,14 @@ struct NVDIMMDevice {
      * guest via ACPI NFIT and _FIT method if NVDIMM hotplug is supported.
      */
     MemoryRegion nvdimm_mr;
+
+    /*
+     * The 'on' value results in the unarmed flag set in ACPI NFIT,
+     * which can be used to notify guest implicitly that the host
+     * backend (e.g., files on HDD, /dev/pmemX, etc.) cannot guarantee
+     * the guest write persistence.
+     */
+    bool unarmed;
 };
 typedef struct NVDIMMDevice NVDIMMDevice;