diff --git a/src/soc/intel/xeon_sp/Makefile.inc b/src/soc/intel/xeon_sp/Makefile.inc
index 40a1020c5c..07fe3debb4 100644
--- a/src/soc/intel/xeon_sp/Makefile.inc
+++ b/src/soc/intel/xeon_sp/Makefile.inc
@@ -6,8 +6,9 @@ subdirs-$(CONFIG_SOC_INTEL_SKYLAKE_SP) += skx
 subdirs-$(CONFIG_SOC_INTEL_COOPERLAKE_SP) += cpx
 
 bootblock-y += bootblock.c spi.c lpc.c gpio.c pch.c
-romstage-y += romstage.c reset.c util.c spi.c gpio.c pmutil.c
+romstage-y += romstage.c reset.c util.c spi.c gpio.c pmutil.c memmap.c
 ramstage-y += uncore.c reset.c util.c lpc.c spi.c gpio.c nb_acpi.c ramstage.c chip_common.c
+ramstage-y += memmap.c
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_PMC) += pmc.c
 ramstage-$(CONFIG_HAVE_ACPI_TABLES) += acpi.c
 postcar-y += spi.c
diff --git a/src/soc/intel/xeon_sp/cpx/include/soc/pci_devs.h b/src/soc/intel/xeon_sp/cpx/include/soc/pci_devs.h
index bb0f877560..68dee28a07 100644
--- a/src/soc/intel/xeon_sp/cpx/include/soc/pci_devs.h
+++ b/src/soc/intel/xeon_sp/cpx/include/soc/pci_devs.h
@@ -77,8 +77,14 @@
 #define VMD_FUNC_NUM            0x05
 
 #define MMAP_VTD_CFG_REG_DEVID		0x2024
-#define VTD_DEV				0x5
-#define VTD_FUNC			0x0
+#define VTD_DEV_NUM			0x5
+#define VTD_FUNC_NUM			0x0
+
+#if !defined(__SIMPLE_DEVICE__)
+#define VTD_DEV(bus)		pcidev_path_on_bus((bus), PCI_DEVFN(VTD_DEV_NUM, VTD_FUNC_NUM))
+#else
+#define VTD_DEV(bus)		PCI_DEV((bus), VTD_DEV_NUM, VTD_FUNC_NUM)
+#endif
 
 #define APIC_DEV_NUM            0x05
 #define APIC_FUNC_NUM           0x04
diff --git a/src/soc/intel/xeon_sp/memmap.c b/src/soc/intel/xeon_sp/memmap.c
new file mode 100644
index 0000000000..79ab47eaed
--- /dev/null
+++ b/src/soc/intel/xeon_sp/memmap.c
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <device/pci_ops.h>
+#include <cpu/x86/smm.h>
+#include <soc/pci_devs.h>
+
+void smm_region(uintptr_t *start, size_t *size)
+{
+	uintptr_t tseg_base = pci_read_config32(VTD_DEV(0), VTD_TSEG_BASE_CSR);
+	uintptr_t tseg_limit = pci_read_config32(VTD_DEV(0), VTD_TSEG_LIMIT_CSR);
+
+	tseg_base = ALIGN_DOWN(tseg_base, 1 * MiB);
+	tseg_limit = ALIGN_DOWN(tseg_limit, 1 * MiB);
+	/* Only the upper [31:20] bits of an address are checked against
+	 * VTD_TSEG_LIMIT_CSR[31:20] which must be below or equal, so this
+	 * effectively means +1MiB for the limit.
+	 */
+	tseg_limit += 1 * MiB;
+
+	*start = tseg_base;
+	*size = tseg_limit - tseg_base;
+}
diff --git a/src/soc/intel/xeon_sp/skx/include/soc/pci_devs.h b/src/soc/intel/xeon_sp/skx/include/soc/pci_devs.h
index 6b84f70d3b..b500c2896c 100644
--- a/src/soc/intel/xeon_sp/skx/include/soc/pci_devs.h
+++ b/src/soc/intel/xeon_sp/skx/include/soc/pci_devs.h
@@ -126,8 +126,14 @@
 #define HPET0_FUNC_NUM          0x00
 
 #define MMAP_VTD_CFG_REG_DEVID		0x2024
-#define VTD_DEV				5
-#define VTD_FUNC			0
+#define VTD_DEV_NUM			0x5
+#define VTD_FUNC_NUM			0x0
+
+#if !defined(__SIMPLE_DEVICE__)
+#define VTD_DEV(bus)		pcidev_path_on_bus((bus), PCI_DEVFN(VTD_DEV_NUM, VTD_FUNC_NUM))
+#else
+#define VTD_DEV(bus)		PCI_DEV((bus), VTD_DEV_NUM, VTD_FUNC_NUM)
+#endif
 
 #define PCH_DEV_SLOT_LPC        0x1f
 #define  PCH_DEVFN_LPC          _PCH_DEVFN(LPC, 0)