diff --git a/docs/misc/xenstore-paths.pandoc b/docs/misc/xenstore-paths.pandoc
index 5cd5c8a3b9..e67e164855 100644
--- a/docs/misc/xenstore-paths.pandoc
+++ b/docs/misc/xenstore-paths.pandoc
@@ -269,6 +269,15 @@ at the guest physical address in HVM_PARAM_VM_GENERATION_ID_ADDR.
 See Microsoft's "Virtual Machine Generation ID" specification for the
 circumstances where the generation ID needs to be changed.
 
+
+#### ~/platform/tpm_version = INTEGER [HVM,INTERNAL]
+
+The TPM version to be probed for.
+
+A value of 1 indicates to probe for TPM 1.2.
+A value of 0 or an invalid value will result in no TPM being probed.
+If unset, a default of 1 is assumed.
+
 ### Frontend device paths
 
 Paravirtual device frontends are generally specified by their own
diff --git a/tools/firmware/hvmloader/util.c b/tools/firmware/hvmloader/util.c
index 581b35e5cf..f39a8e584f 100644
--- a/tools/firmware/hvmloader/util.c
+++ b/tools/firmware/hvmloader/util.c
@@ -994,13 +994,22 @@ void hvmloader_acpi_build_tables(struct acpi_config *config,
     if ( !strncmp(xenstore_read("platform/acpi_laptop_slate", "0"), "1", 1)  )
         config->table_flags |= ACPI_HAS_SSDT_LAPTOP_SLATE;
 
-    config->table_flags |= (ACPI_HAS_TCPA | ACPI_HAS_IOAPIC |
-                            ACPI_HAS_WAET | ACPI_HAS_PMTIMER |
-                            ACPI_HAS_BUTTONS | ACPI_HAS_VGA |
-                            ACPI_HAS_8042 | ACPI_HAS_CMOS_RTC);
+    config->table_flags |= (ACPI_HAS_IOAPIC | ACPI_HAS_WAET |
+                            ACPI_HAS_PMTIMER | ACPI_HAS_BUTTONS |
+                            ACPI_HAS_VGA | ACPI_HAS_8042 |
+                            ACPI_HAS_CMOS_RTC);
     config->acpi_revision = 4;
 
-    config->tis_hdr = (uint16_t *)ACPI_TIS_HDR_ADDRESS;
+    s = xenstore_read("platform/tpm_version", "1");
+    config->tpm_version = strtoll(s, NULL, 0);
+
+    switch( config->tpm_version )
+    {
+    case 1:
+        config->table_flags |= ACPI_HAS_TPM;
+        config->tis_hdr = (uint16_t *)ACPI_TIS_HDR_ADDRESS;
+        break;
+    }
 
     config->numa.nr_vmemranges = nr_vmemranges;
     config->numa.nr_vnodes = nr_vnodes;
diff --git a/tools/libacpi/build.c b/tools/libacpi/build.c
index fe2db66a62..716cb49624 100644
--- a/tools/libacpi/build.c
+++ b/tools/libacpi/build.c
@@ -409,38 +409,47 @@ static int construct_secondary_tables(struct acpi_ctxt *ctxt,
         memcpy(ssdt, ssdt_laptop_slate, sizeof(ssdt_laptop_slate));
         table_ptrs[nr_tables++] = ctxt->mem_ops.v2p(ctxt, ssdt);
     }
-
-    /* TPM TCPA and SSDT. */
-    if ( (config->table_flags & ACPI_HAS_TCPA) &&
-         (config->tis_hdr[0] != 0 && config->tis_hdr[0] != 0xffff) &&
-         (config->tis_hdr[1] != 0 && config->tis_hdr[1] != 0xffff) )
+    /* TPM and its SSDT. */
+    if ( config->table_flags & ACPI_HAS_TPM )
     {
-        ssdt = ctxt->mem_ops.alloc(ctxt, sizeof(ssdt_tpm), 16);
-        if (!ssdt) return -1;
-        memcpy(ssdt, ssdt_tpm, sizeof(ssdt_tpm));
-        table_ptrs[nr_tables++] = ctxt->mem_ops.v2p(ctxt, ssdt);
-
-        tcpa = ctxt->mem_ops.alloc(ctxt, sizeof(struct acpi_20_tcpa), 16);
-        if (!tcpa) return -1;
-        memset(tcpa, 0, sizeof(*tcpa));
-        table_ptrs[nr_tables++] = ctxt->mem_ops.v2p(ctxt, tcpa);
-
-        tcpa->header.signature = ACPI_2_0_TCPA_SIGNATURE;
-        tcpa->header.length    = sizeof(*tcpa);
-        tcpa->header.revision  = ACPI_2_0_TCPA_REVISION;
-        fixed_strcpy(tcpa->header.oem_id, ACPI_OEM_ID);
-        fixed_strcpy(tcpa->header.oem_table_id, ACPI_OEM_TABLE_ID);
-        tcpa->header.oem_revision = ACPI_OEM_REVISION;
-        tcpa->header.creator_id   = ACPI_CREATOR_ID;
-        tcpa->header.creator_revision = ACPI_CREATOR_REVISION;
-        if ( (lasa = ctxt->mem_ops.alloc(ctxt, ACPI_2_0_TCPA_LAML_SIZE, 16)) != NULL )
+        switch ( config->tpm_version )
         {
-            tcpa->lasa = ctxt->mem_ops.v2p(ctxt, lasa);
-            tcpa->laml = ACPI_2_0_TCPA_LAML_SIZE;
-            memset(lasa, 0, tcpa->laml);
-            set_checksum(tcpa,
-                         offsetof(struct acpi_header, checksum),
-                         tcpa->header.length);
+        case 0: /* Assume legacy code wanted tpm 1.2 */
+        case 1:
+            if ( config->tis_hdr[0] == 0 || config->tis_hdr[0] == 0xffff ||
+                 config->tis_hdr[1] == 0 || config->tis_hdr[1] == 0xffff )
+                break;
+
+            ssdt = ctxt->mem_ops.alloc(ctxt, sizeof(ssdt_tpm), 16);
+            if (!ssdt) return -1;
+            memcpy(ssdt, ssdt_tpm, sizeof(ssdt_tpm));
+            table_ptrs[nr_tables++] = ctxt->mem_ops.v2p(ctxt, ssdt);
+
+            tcpa = ctxt->mem_ops.alloc(ctxt, sizeof(struct acpi_20_tcpa), 16);
+            if (!tcpa) return -1;
+            memset(tcpa, 0, sizeof(*tcpa));
+            table_ptrs[nr_tables++] = ctxt->mem_ops.v2p(ctxt, tcpa);
+
+            tcpa->header.signature = ACPI_2_0_TCPA_SIGNATURE;
+            tcpa->header.length    = sizeof(*tcpa);
+            tcpa->header.revision  = ACPI_2_0_TCPA_REVISION;
+            fixed_strcpy(tcpa->header.oem_id, ACPI_OEM_ID);
+            fixed_strcpy(tcpa->header.oem_table_id, ACPI_OEM_TABLE_ID);
+            tcpa->header.oem_revision = ACPI_OEM_REVISION;
+            tcpa->header.creator_id   = ACPI_CREATOR_ID;
+            tcpa->header.creator_revision = ACPI_CREATOR_REVISION;
+
+            lasa = ctxt->mem_ops.alloc(ctxt, ACPI_2_0_TCPA_LAML_SIZE, 16);
+            if ( lasa )
+            {
+                tcpa->lasa = ctxt->mem_ops.v2p(ctxt, lasa);
+                tcpa->laml = ACPI_2_0_TCPA_LAML_SIZE;
+                memset(lasa, 0, tcpa->laml);
+                set_checksum(tcpa,
+                             offsetof(struct acpi_header, checksum),
+                             tcpa->header.length);
+            }
+            break;
         }
     }
 
diff --git a/tools/libacpi/libacpi.h b/tools/libacpi/libacpi.h
index a2efd23b0b..f69452401f 100644
--- a/tools/libacpi/libacpi.h
+++ b/tools/libacpi/libacpi.h
@@ -27,7 +27,7 @@
 #define ACPI_HAS_SSDT_PM           (1<<4)
 #define ACPI_HAS_SSDT_S3           (1<<5)
 #define ACPI_HAS_SSDT_S4           (1<<6)
-#define ACPI_HAS_TCPA              (1<<7)
+#define ACPI_HAS_TPM               (1<<7)
 #define ACPI_HAS_IOAPIC            (1<<8)
 #define ACPI_HAS_WAET              (1<<9)
 #define ACPI_HAS_PMTIMER           (1<<10)
@@ -66,6 +66,7 @@ struct acpi_config {
 
     uint32_t table_flags;
     uint8_t acpi_revision;
+    uint8_t tpm_version;
 
     uint64_t vm_gid[2];
     unsigned long vm_gid_addr; /* OUT parameter */
