kvm/tdx: Don't complain when converting vMMIO region to shared

Because vMMIO region needs to be shared region, guest TD may explicitly
convert such region from private to shared.  Don't complain such
conversion.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-ID: <20240229063726.610065-34-xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

accel/kvm/kvm-all.c

@@ -2927,9 +2927,22 @@ int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private)
     }
 
     if (!memory_region_has_guest_memfd(mr)) {
-        error_report("Converting non guest_memfd backed memory region "
-                     "(0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") to %s",
-                     start, size, to_private ? "private" : "shared");
+        /*
+         * Because vMMIO region must be shared, guest TD may convert vMMIO
+         * region to shared explicitly.  Don't complain such case.  See
+         * memory_region_type() for checking if the region is MMIO region.
+         */
+        if (!to_private &&
+            !memory_region_is_ram(mr) &&
+            !memory_region_is_ram_device(mr) &&
+            !memory_region_is_rom(mr) &&
+            !memory_region_is_romd(mr)) {
+		    ret = 0;
+        } else {
+            error_report("Convert non guest_memfd backed memory region "
+                        "(0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") to %s",
+                        start, size, to_private ? "private" : "shared");
+        }
         goto out_unref;
     }