diff --git a/include/hw/cxl/cxl_mailbox.h b/include/hw/cxl/cxl_mailbox.h
new file mode 100644
index 0000000000..beb048052e
--- /dev/null
+++ b/include/hw/cxl/cxl_mailbox.h
@@ -0,0 +1,18 @@
+/*
+ * QEMU CXL Mailbox
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See the
+ * COPYING file in the top-level directory.
+ */
+
+#ifndef CXL_MAILBOX_H
+#define CXL_MAILBOX_H
+
+#define CXL_MBOX_IMMEDIATE_CONFIG_CHANGE (1 << 1)
+#define CXL_MBOX_IMMEDIATE_DATA_CHANGE (1 << 2)
+#define CXL_MBOX_IMMEDIATE_POLICY_CHANGE (1 << 3)
+#define CXL_MBOX_IMMEDIATE_LOG_CHANGE (1 << 4)
+#define CXL_MBOX_SECURITY_STATE_CHANGE (1 << 5)
+#define CXL_MBOX_BACKGROUND_OPERATION (1 << 6)
+
+#endif
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 82120a6e7b..dbaa83a110 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -12,6 +12,7 @@
 #include "hw/pci/msix.h"
 #include "hw/cxl/cxl.h"
 #include "hw/cxl/cxl_events.h"
+#include "hw/cxl/cxl_mailbox.h"
 #include "hw/pci/pci.h"
 #include "hw/pci-bridge/cxl_upstream_port.h"
 #include "qemu/cutils.h"
@@ -2095,28 +2096,21 @@ static CXLRetCode cmd_dcd_release_dyn_cap(const struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
-#define IMMEDIATE_CONFIG_CHANGE (1 << 1)
-#define IMMEDIATE_DATA_CHANGE (1 << 2)
-#define IMMEDIATE_POLICY_CHANGE (1 << 3)
-#define IMMEDIATE_LOG_CHANGE (1 << 4)
-#define SECURITY_STATE_CHANGE (1 << 5)
-#define BACKGROUND_OPERATION (1 << 6)
-
 static const struct cxl_cmd cxl_cmd_set[256][256] = {
     [EVENTS][GET_RECORDS] = { "EVENTS_GET_RECORDS",
         cmd_events_get_records, 1, 0 },
     [EVENTS][CLEAR_RECORDS] = { "EVENTS_CLEAR_RECORDS",
-        cmd_events_clear_records, ~0, IMMEDIATE_LOG_CHANGE },
+        cmd_events_clear_records, ~0, CXL_MBOX_IMMEDIATE_LOG_CHANGE },
     [EVENTS][GET_INTERRUPT_POLICY] = { "EVENTS_GET_INTERRUPT_POLICY",
                                       cmd_events_get_interrupt_policy, 0, 0 },
     [EVENTS][SET_INTERRUPT_POLICY] = { "EVENTS_SET_INTERRUPT_POLICY",
                                       cmd_events_set_interrupt_policy,
-                                      ~0, IMMEDIATE_CONFIG_CHANGE },
+                                      ~0, CXL_MBOX_IMMEDIATE_CONFIG_CHANGE },
     [FIRMWARE_UPDATE][GET_INFO] = { "FIRMWARE_UPDATE_GET_INFO",
         cmd_firmware_update_get_info, 0, 0 },
     [TIMESTAMP][GET] = { "TIMESTAMP_GET", cmd_timestamp_get, 0, 0 },
     [TIMESTAMP][SET] = { "TIMESTAMP_SET", cmd_timestamp_set,
-                         8, IMMEDIATE_POLICY_CHANGE },
+                         8, CXL_MBOX_IMMEDIATE_POLICY_CHANGE },
     [LOGS][GET_SUPPORTED] = { "LOGS_GET_SUPPORTED", cmd_logs_get_supported,
                               0, 0 },
     [LOGS][GET_LOG] = { "LOGS_GET_LOG", cmd_logs_get_log, 0x18, 0 },
@@ -2126,9 +2120,11 @@ static const struct cxl_cmd cxl_cmd_set[256][256] = {
         cmd_ccls_get_partition_info, 0, 0 },
     [CCLS][GET_LSA] = { "CCLS_GET_LSA", cmd_ccls_get_lsa, 8, 0 },
     [CCLS][SET_LSA] = { "CCLS_SET_LSA", cmd_ccls_set_lsa,
-        ~0, IMMEDIATE_CONFIG_CHANGE | IMMEDIATE_DATA_CHANGE },
+        ~0, CXL_MBOX_IMMEDIATE_CONFIG_CHANGE | CXL_MBOX_IMMEDIATE_DATA_CHANGE },
     [SANITIZE][OVERWRITE] = { "SANITIZE_OVERWRITE", cmd_sanitize_overwrite, 0,
-        IMMEDIATE_DATA_CHANGE | SECURITY_STATE_CHANGE | BACKGROUND_OPERATION },
+        (CXL_MBOX_IMMEDIATE_DATA_CHANGE |
+         CXL_MBOX_SECURITY_STATE_CHANGE |
+         CXL_MBOX_BACKGROUND_OPERATION)},
     [PERSISTENT_MEM][GET_SECURITY_STATE] = { "GET_SECURITY_STATE",
         cmd_get_security_state, 0, 0 },
     [MEDIA_AND_POISON][GET_POISON_LIST] = { "MEDIA_AND_POISON_GET_POISON_LIST",
@@ -2141,7 +2137,7 @@ static const struct cxl_cmd cxl_cmd_set[256][256] = {
         "MEDIA_AND_POISON_GET_SCAN_MEDIA_CAPABILITIES",
         cmd_media_get_scan_media_capabilities, 16, 0 },
     [MEDIA_AND_POISON][SCAN_MEDIA] = { "MEDIA_AND_POISON_SCAN_MEDIA",
-        cmd_media_scan_media, 17, BACKGROUND_OPERATION },
+        cmd_media_scan_media, 17, CXL_MBOX_BACKGROUND_OPERATION },
     [MEDIA_AND_POISON][GET_SCAN_MEDIA_RESULTS] = {
         "MEDIA_AND_POISON_GET_SCAN_MEDIA_RESULTS",
         cmd_media_get_scan_media_results, 0, 0 },
@@ -2155,10 +2151,10 @@ static const struct cxl_cmd cxl_cmd_set_dcd[256][256] = {
         8, 0 },
     [DCD_CONFIG][ADD_DYN_CAP_RSP] = {
         "DCD_ADD_DYNAMIC_CAPACITY_RESPONSE", cmd_dcd_add_dyn_cap_rsp,
-        ~0, IMMEDIATE_DATA_CHANGE },
+        ~0, CXL_MBOX_IMMEDIATE_DATA_CHANGE },
     [DCD_CONFIG][RELEASE_DYN_CAP] = {
         "DCD_RELEASE_DYNAMIC_CAPACITY", cmd_dcd_release_dyn_cap,
-        ~0, IMMEDIATE_DATA_CHANGE },
+        ~0, CXL_MBOX_IMMEDIATE_DATA_CHANGE },
 };
 
 static const struct cxl_cmd cxl_cmd_set_sw[256][256] = {
@@ -2166,8 +2162,8 @@ static const struct cxl_cmd cxl_cmd_set_sw[256][256] = {
     [INFOSTAT][BACKGROUND_OPERATION_STATUS] = { "BACKGROUND_OPERATION_STATUS",
         cmd_infostat_bg_op_sts, 0, 0 },
     [TIMESTAMP][GET] = { "TIMESTAMP_GET", cmd_timestamp_get, 0, 0 },
-    [TIMESTAMP][SET] = { "TIMESTAMP_SET", cmd_timestamp_set, 0,
-                         IMMEDIATE_POLICY_CHANGE },
+    [TIMESTAMP][SET] = { "TIMESTAMP_SET", cmd_timestamp_set, 8,
+                         CXL_MBOX_IMMEDIATE_POLICY_CHANGE },
     [LOGS][GET_SUPPORTED] = { "LOGS_GET_SUPPORTED", cmd_logs_get_supported, 0,
                               0 },
     [LOGS][GET_LOG] = { "LOGS_GET_LOG", cmd_logs_get_log, 0x18, 0 },
@@ -2210,7 +2206,7 @@ int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
     }
 
     /* Only one bg command at a time */
-    if ((cxl_cmd->effect & BACKGROUND_OPERATION) &&
+    if ((cxl_cmd->effect & CXL_MBOX_BACKGROUND_OPERATION) &&
         cci->bg.runtime > 0) {
         return CXL_MBOX_BUSY;
     }
@@ -2235,7 +2231,7 @@ int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
     }
 
     ret = (*h)(cxl_cmd, pl_in, len_in, pl_out, len_out, cci);
-    if ((cxl_cmd->effect & BACKGROUND_OPERATION) &&
+    if ((cxl_cmd->effect & CXL_MBOX_BACKGROUND_OPERATION) &&
         ret == CXL_MBOX_BG_STARTED) {
         *bg_started = true;
     } else {
