diff --git a/hw/cxl/cxl-device-utils.c b/hw/cxl/cxl-device-utils.c
index 035d034f6dd8..1a9779ed8201 100644
--- a/hw/cxl/cxl-device-utils.c
+++ b/hw/cxl/cxl-device-utils.c
@@ -95,11 +95,14 @@ static uint64_t mailbox_reg_read(void *opaque, hwaddr offset, unsigned size)
         }
         if (offset == A_CXL_DEV_MAILBOX_STS) {
             uint64_t status_reg = cxl_dstate->mbox_reg_state64[offset / size];
-            if (cci->bg.complete_pct) {
+
+            qemu_mutex_lock(&cci->bg.lock);
+            if (cci->bg.complete_pct == 100 || cci->bg.aborted) {
                 status_reg = FIELD_DP64(status_reg, CXL_DEV_MAILBOX_STS, BG_OP,
                                         0);
                 cxl_dstate->mbox_reg_state64[offset / size] = status_reg;
             }
+            qemu_mutex_unlock(&cci->bg.lock);
         }
         return cxl_dstate->mbox_reg_state64[offset / size];
     default:
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index b752920ec88a..ff12dfc3dcc4 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -56,6 +56,7 @@ enum {
     INFOSTAT    = 0x00,
         #define IS_IDENTIFY   0x1
         #define BACKGROUND_OPERATION_STATUS    0x2
+        #define BACKGROUND_OPERATION_ABORT     0x5
     EVENTS      = 0x01,
         #define GET_RECORDS   0x0
         #define CLEAR_RECORDS   0x1
@@ -624,6 +625,38 @@ static CXLRetCode cmd_infostat_bg_op_sts(const struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
+/* CXL r3.1 Section 8.2.9.1.5: Request Abort Background Operation (Opcode 0005h) */
+static CXLRetCode cmd_infostat_bg_op_abort(const struct cxl_cmd *cmd,
+                                           uint8_t *payload_in,
+                                           size_t len_in,
+                                           uint8_t *payload_out,
+                                           size_t *len_out,
+                                           CXLCCI *cci)
+{
+    int bg_set = cci->bg.opcode >> 8;
+    int bg_cmd = cci->bg.opcode & 0xff;
+    const struct cxl_cmd *bg_c = &cci->cxl_cmd_set[bg_set][bg_cmd];
+
+    if (!(bg_c->effect & CXL_MBOX_BACKGROUND_OPERATION_ABORT)) {
+        return CXL_MBOX_REQUEST_ABORT_NOTSUP;
+    }
+
+    qemu_mutex_lock(&cci->bg.lock);
+    if (cci->bg.runtime) {
+        /* operation is near complete, let it finish */
+        if (cci->bg.complete_pct < 85) {
+            timer_del(cci->bg.timer);
+            cci->bg.ret_code = CXL_MBOX_ABORTED;
+            cci->bg.starttime = 0;
+            cci->bg.runtime = 0;
+            cci->bg.aborted = true;
+        }
+    }
+    qemu_mutex_unlock(&cci->bg.lock);
+
+    return CXL_MBOX_SUCCESS;
+}
+
 #define CXL_FW_SLOTS 2
 #define CXL_FW_SIZE  0x02000000 /* 32 mb */
 
@@ -2665,6 +2698,8 @@ static CXLRetCode cmd_dcd_release_dyn_cap(const struct cxl_cmd *cmd,
 }
 
 static const struct cxl_cmd cxl_cmd_set[256][256] = {
+    [INFOSTAT][BACKGROUND_OPERATION_ABORT] = { "BACKGROUND_OPERATION_ABORT",
+        cmd_infostat_bg_op_abort, 0, 0 },
     [EVENTS][GET_RECORDS] = { "EVENTS_GET_RECORDS",
         cmd_events_get_records, 1, 0 },
     [EVENTS][CLEAR_RECORDS] = { "EVENTS_CLEAR_RECORDS",
@@ -2708,7 +2743,8 @@ static const struct cxl_cmd cxl_cmd_set[256][256] = {
     [SANITIZE][OVERWRITE] = { "SANITIZE_OVERWRITE", cmd_sanitize_overwrite, 0,
         (CXL_MBOX_IMMEDIATE_DATA_CHANGE |
          CXL_MBOX_SECURITY_STATE_CHANGE |
-         CXL_MBOX_BACKGROUND_OPERATION)},
+         CXL_MBOX_BACKGROUND_OPERATION |
+         CXL_MBOX_BACKGROUND_OPERATION_ABORT)},
     [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",
@@ -2721,7 +2757,8 @@ 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, CXL_MBOX_BACKGROUND_OPERATION },
+        cmd_media_scan_media, 17,
+        (CXL_MBOX_BACKGROUND_OPERATION | CXL_MBOX_BACKGROUND_OPERATION_ABORT)},
     [MEDIA_AND_POISON][GET_SCAN_MEDIA_RESULTS] = {
         "MEDIA_AND_POISON_GET_SCAN_MEDIA_RESULTS",
         cmd_media_get_scan_media_results, 0, 0 },
@@ -2745,6 +2782,8 @@ static const struct cxl_cmd cxl_cmd_set_sw[256][256] = {
     [INFOSTAT][IS_IDENTIFY] = { "IDENTIFY", cmd_infostat_identify, 0, 0 },
     [INFOSTAT][BACKGROUND_OPERATION_STATUS] = { "BACKGROUND_OPERATION_STATUS",
         cmd_infostat_bg_op_sts, 0, 0 },
+    [INFOSTAT][BACKGROUND_OPERATION_ABORT] = { "BACKGROUND_OPERATION_ABORT",
+        cmd_infostat_bg_op_abort, 0, 0 },
     [TIMESTAMP][GET] = { "TIMESTAMP_GET", cmd_timestamp_get, 0, 0 },
     [TIMESTAMP][SET] = { "TIMESTAMP_SET", cmd_timestamp_set, 8,
                          CXL_MBOX_IMMEDIATE_POLICY_CHANGE },
@@ -2831,6 +2870,7 @@ int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
         cci->bg.opcode = (set << 8) | cmd;
 
         cci->bg.complete_pct = 0;
+        cci->bg.aborted = false;
         cci->bg.ret_code = 0;
 
         now = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
@@ -2844,10 +2884,12 @@ int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
 static void bg_timercb(void *opaque)
 {
     CXLCCI *cci = opaque;
-    uint64_t now = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
-    uint64_t total_time = cci->bg.starttime + cci->bg.runtime;
+    uint64_t now, total_time;
+
+    qemu_mutex_lock(&cci->bg.lock);
 
-    assert(cci->bg.runtime > 0);
+    now = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
+    total_time = cci->bg.starttime + cci->bg.runtime;
 
     if (now >= total_time) { /* we are done */
         uint16_t ret = CXL_MBOX_SUCCESS;
@@ -2899,6 +2941,8 @@ static void bg_timercb(void *opaque)
             msi_notify(pdev, cxl_dstate->mbox_msi_n);
         }
     }
+
+    qemu_mutex_unlock(&cci->bg.lock);
 }
 
 static void cxl_rebuild_cel(CXLCCI *cci)
@@ -2927,12 +2971,21 @@ void cxl_init_cci(CXLCCI *cci, size_t payload_max)
     cci->bg.complete_pct = 0;
     cci->bg.starttime = 0;
     cci->bg.runtime = 0;
+    cci->bg.aborted = false;
     cci->bg.timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
                                  bg_timercb, cci);
+    qemu_mutex_init(&cci->bg.lock);
 
     memset(&cci->fw, 0, sizeof(cci->fw));
     cci->fw.active_slot = 1;
     cci->fw.slot[cci->fw.active_slot - 1] = true;
+    cci->initialized = true;
+}
+
+void cxl_destroy_cci(CXLCCI *cci)
+{
+    qemu_mutex_destroy(&cci->bg.lock);
+    cci->initialized = false;
 }
 
 static void cxl_copy_cci_commands(CXLCCI *cci, const struct cxl_cmd (*cxl_cmds)[256])
diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index 4114163324bd..f04aa58ea85d 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -961,6 +961,7 @@ static void ct3_exit(PCIDevice *pci_dev)
     pcie_aer_exit(pci_dev);
     cxl_doe_cdat_release(cxl_cstate);
     g_free(regs->special_ops);
+    cxl_destroy_cci(&ct3d->cci);
     if (ct3d->dc.host_dc) {
         cxl_destroy_dc_regions(ct3d);
         address_space_destroy(&ct3d->dc.host_dc_as);
@@ -1209,12 +1210,17 @@ static void ct3d_reset(DeviceState *dev)
      * Bring up an endpoint to target with MCTP over VDM.
      * This device is emulating an MLD with single LD for now.
      */
+    if (ct3d->vdm_fm_owned_ld_mctp_cci.initialized) {
+        cxl_destroy_cci(&ct3d->vdm_fm_owned_ld_mctp_cci);
+    }
     cxl_initialize_t3_fm_owned_ld_mctpcci(&ct3d->vdm_fm_owned_ld_mctp_cci,
                                           DEVICE(ct3d), DEVICE(ct3d),
                                           512); /* Max payload made up */
+    if (ct3d->ld0_cci.initialized) {
+        cxl_destroy_cci(&ct3d->ld0_cci);
+    }
     cxl_initialize_t3_ld_cci(&ct3d->ld0_cci, DEVICE(ct3d), DEVICE(ct3d),
                              512); /* Max payload made up */
-
 }
 
 static Property ct3_props[] = {
diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index e14e56ae4bc2..c0e8d40053db 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -176,10 +176,12 @@ typedef struct CXLCCI {
         uint16_t opcode;
         uint16_t complete_pct;
         uint16_t ret_code; /* Current value of retcode */
+        bool aborted;
         uint64_t starttime;
         /* set by each bg cmd, cleared by the bg_timer when complete */
         uint64_t runtime;
         QEMUTimer *timer;
+        QemuMutex lock; /* serializes mbox abort vs timer cb */
     } bg;
 
     /* firmware update */
@@ -201,6 +203,7 @@ typedef struct CXLCCI {
     DeviceState *d;
     /* Pointer to the device hosting the protocol conversion */
     DeviceState *intf;
+    bool initialized;
 } CXLCCI;
 
 typedef struct cxl_device_state {
@@ -316,6 +319,7 @@ void cxl_initialize_mailbox_t3(CXLCCI *cci, DeviceState *d, size_t payload_max);
 void cxl_initialize_mailbox_swcci(CXLCCI *cci, DeviceState *intf,
                                   DeviceState *d, size_t payload_max);
 void cxl_init_cci(CXLCCI *cci, size_t payload_max);
+void cxl_destroy_cci(CXLCCI *cci);
 void cxl_add_cci_commands(CXLCCI *cci, const struct cxl_cmd (*cxl_cmd_set)[256],
                           size_t payload_max);
 int cxl_process_cci_message(CXLCCI *cci, uint8_t set, uint8_t cmd,
diff --git a/include/hw/cxl/cxl_mailbox.h b/include/hw/cxl/cxl_mailbox.h
index beb048052e1b..9008402d1c46 100644
--- a/include/hw/cxl/cxl_mailbox.h
+++ b/include/hw/cxl/cxl_mailbox.h
@@ -14,5 +14,6 @@
 #define CXL_MBOX_IMMEDIATE_LOG_CHANGE (1 << 4)
 #define CXL_MBOX_SECURITY_STATE_CHANGE (1 << 5)
 #define CXL_MBOX_BACKGROUND_OPERATION (1 << 6)
+#define CXL_MBOX_BACKGROUND_OPERATION_ABORT (1 << 7)
 
 #endif
