mch.below_4g_mem_size, 0),
     DEFINE_PROP_SIZE(PCI_HOST_ABOVE_4G_MEM_SIZE, Q35PCIHost,
                      mch.above_4g_mem_size, 0),
+    DEFINE_PROP_BOOL(PCI_HOST_PROP_SMM_RANGES, Q35PCIHost,
+                     mch.has_smm_ranges, true),
     DEFINE_PROP_BOOL("x-pci-hole64-fix", Q35PCIHost, pci_hole64_fix, true),
     DEFINE_PROP_END_OF_LIST(),
 };
     /* mch's object_initialize resets the default value, set it again */
     qdev_prop_set_uint64(DEVICE(s), PCI_HOST_PROP_PCI_HOLE64_SIZE,
                          Q35_PCI_HOST_HOLE64_SIZE_DEFAULT);
+
     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE_START, "uint32",
                         q35_host_get_pci_hole_start,
                         NULL, NULL, NULL);
         mch_update_pciexbar(mch);
     }
 
+    if (!mch->has_smm_ranges) {
+        return;
+    }
+
     if (ranges_overlap(address, len, MCH_HOST_BRIDGE_SMRAM,
                        MCH_HOST_BRIDGE_SMRAM_SIZE)) {
         mch_update_smram(mch);
 static void mch_update(MCHPCIState *mch)
 {
     mch_update_pciexbar(mch);
+
     mch_update_pam(mch);
-    mch_update_smram(mch);
-    mch_update_ext_tseg_mbytes(mch);
-    mch_update_smbase_smram(mch);
+    if (mch->has_smm_ranges) {
+        mch_update_smram(mch);
+        mch_update_ext_tseg_mbytes(mch);
+        mch_update_smbase_smram(mch);
+    }
 
     /*
      * pci hole goes from end-of-low-ram to io-apic.
     pci_set_quad(d->config + MCH_HOST_BRIDGE_PCIEXBAR,
                  MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT);
 
-    d->config[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_DEFAULT;
-    d->config[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_DEFAULT;
-    d->wmask[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_WMASK;
-    d->wmask[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_WMASK;
+    if (mch->has_smm_ranges) {
+        d->config[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_DEFAULT;
+        d->config[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_DEFAULT;
+        d->wmask[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_WMASK;
+        d->wmask[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_WMASK;
 
-    if (mch->ext_tseg_mbytes > 0) {
-        pci_set_word(d->config + MCH_HOST_BRIDGE_EXT_TSEG_MBYTES,
-                     MCH_HOST_BRIDGE_EXT_TSEG_MBYTES_QUERY);
-    }
+        if (mch->ext_tseg_mbytes > 0) {
+            pci_set_word(d->config + MCH_HOST_BRIDGE_EXT_TSEG_MBYTES,
+                        MCH_HOST_BRIDGE_EXT_TSEG_MBYTES_QUERY);
+        }
 
-    d->config[MCH_HOST_BRIDGE_F_SMBASE] = 0;
-    d->wmask[MCH_HOST_BRIDGE_F_SMBASE] = 0xff;
+        d->config[MCH_HOST_BRIDGE_F_SMBASE] = 0;
+        d->wmask[MCH_HOST_BRIDGE_F_SMBASE] = 0xff;
+    }
 
     mch_update(mch);
 }
                  PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE, PAM_EXPAN_SIZE);
     }
 
+    if (!mch->has_smm_ranges) {
+        return;
+    }
+
     /* if *disabled* show SMRAM to all CPUs */
     memory_region_init_alias(&mch->smram_region, OBJECT(mch), "smram-region",
                              mch->pci_address_space, MCH_HOST_BRIDGE_SMRAM_C_BASE,