"fill-mtee-mask" was previously disabled only on PC-Q35-2.6 and
PC-I440FX-2.6 machines, but PC v2.6 machines have been deprecated and
will be removed.

Considerring it may have external use, so deprecate it before removal.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
 docs/about/deprecated.rst | 8 ++++++++
 target/i386/cpu.c         | 3 ++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 1d5c4f3707cb..0e8a25e37414 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -448,6 +448,14 @@ Backend ``memory`` (since 9.0)
 CPU device properties
 '''''''''''''''''''''
 
+``fill-mtrr-mask`` on x86 (since 11.0)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``fill-mtrr-mask=true`` fill the bits between 51..number-of-physical-address
+-bits in the MTRR_PHYSMASKn variable range mtrr masks. It was previously set to
+false only on PC-Q35-2.6 and PC-I440FX-2.6 machines, but PC v2.6 machines have
+been removed. Deprecate this property to stop external use.
+
 ``pmu-num=n`` on RISC-V CPUs (since 8.2)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 94a9dcde1eb1..13ccb1702d32 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -10510,7 +10510,8 @@ static const Property x86_cpu_properties[] = {
     DEFINE_PROP_UINT32("guest-phys-bits", X86CPU, guest_phys_bits, -1),
     DEFINE_PROP_BOOL("host-phys-bits", X86CPU, host_phys_bits, false),
     DEFINE_PROP_UINT8("host-phys-bits-limit", X86CPU, host_phys_bits_limit, 0),
-    DEFINE_PROP_BOOL("fill-mtrr-mask", X86CPU, fill_mtrr_mask, true),
+    DEFINE_PROP_BOOL("fill-mtrr-mask", X86CPU, fill_mtrr_mask, true,
+                     .flags = OBJ_PROP_FLAG_DEPRECATED),
     DEFINE_PROP_UINT32("level-func7", X86CPU, env.cpuid_level_func7,
                        UINT32_MAX),
     DEFINE_PROP_UINT32("level", X86CPU, env.cpuid_level, UINT32_MAX),
-- 
2.34.1