diff --git a/devicemodel/core/vmmapi.c b/devicemodel/core/vmmapi.c
index 72f35e10a..72f1de6a1 100644
--- a/devicemodel/core/vmmapi.c
+++ b/devicemodel/core/vmmapi.c
@@ -672,13 +672,13 @@ vm_irqfd(struct vmctx *ctx, struct acrn_irqfd *args)
 }
 
 int
-vm_get_config(struct vmctx *ctx, struct acrn_vm_config *vm_cfg, struct platform_info *plat_info)
+vm_get_config(struct vmctx *ctx, struct acrn_vm_config_header *vm_cfg, struct acrn_platform_info *plat_info)
 {
 #define VM_CFG_BUFF_SIZE 0x8000
 	int i, err = 0;
 	uint8_t *configs_buff;
-	struct acrn_vm_config *pcfg;
-	struct platform_info platform_info;
+	struct acrn_vm_config_header *pcfg;
+	struct acrn_platform_info platform_info;
 
 	if ((ctx == NULL) || (vm_cfg == NULL))
 		return -1;
@@ -690,31 +690,31 @@ vm_get_config(struct vmctx *ctx, struct acrn_vm_config *vm_cfg, struct platform_
 	}
 
 	bzero(&platform_info, sizeof(platform_info));
-	platform_info.vm_configs_addr = (uint64_t)configs_buff;
-	err = ioctl(ctx->fd, IC_GET_PLATFORM_INFO, &platform_info);
+	platform_info.sw.vm_configs_addr = configs_buff;
+	err = ioctl(ctx->fd, ACRN_IOCTL_GET_PLATFORM_INFO, &platform_info);
 	if (err) {
 		pr_err("%s, failed: get platform info.\n", __func__);
 		goto exit;
 	}
-	assert(VM_CFG_BUFF_SIZE > (platform_info.max_vms * platform_info.vm_config_entry_size));
+	assert(VM_CFG_BUFF_SIZE > (platform_info.sw.max_vms * platform_info.sw.vm_config_size));
 
-	for (i = 0; i < platform_info.max_vms; i++) {
-		pcfg = (struct acrn_vm_config *)(configs_buff + (i * platform_info.vm_config_entry_size));
+	for (i = 0; i < platform_info.sw.max_vms; i++) {
+		pcfg = (struct acrn_vm_config_header *)(configs_buff + (i * platform_info.sw.vm_config_size));
 		if (!uuid_compare(ctx->vm_uuid, pcfg->uuid))
 			break;
 	}
 
-	if (i == platform_info.max_vms) {
+	if (i == platform_info.sw.max_vms) {
 		pr_err("%s, Not found target VM.\n", __func__);
 		err = -1;
 		goto exit;
 	}
 
-	memcpy((void *)vm_cfg, (void *)pcfg, sizeof(struct acrn_vm_config));
+	memcpy((void *)vm_cfg, (void *)pcfg, sizeof(struct acrn_vm_config_header));
 	if (plat_info != NULL) {
-		memcpy((void *)plat_info, (void *)&platform_info, sizeof(struct platform_info));
+		memcpy((void *)plat_info, (void *)&platform_info, sizeof(struct acrn_platform_info));
 		pr_info("%s, l2_cat_shift=%u, l3_cat_shift=%u\n",
-			__func__, platform_info.l2_cat_shift, platform_info.l3_cat_shift);
+			__func__, platform_info.hw.l2_cat_shift, platform_info.hw.l3_cat_shift);
 	}
 
 exit:
diff --git a/devicemodel/hw/platform/acpi/acpi.c b/devicemodel/hw/platform/acpi/acpi.c
index 1af259c05..52a19e9b1 100644
--- a/devicemodel/hw/platform/acpi/acpi.c
+++ b/devicemodel/hw/platform/acpi/acpi.c
@@ -274,17 +274,17 @@ int pcpuid_from_vcpuid(uint64_t guest_pcpu_bitmask, int vcpu_id)
 	return find_nth_set_bit_index(guest_pcpu_bitmask, vcpu_id);
 }
 
-int lapicid_from_pcpuid(struct platform_info *plat_info, int pcpu_id)
+int lapicid_from_pcpuid(struct acrn_platform_info *plat_info, int pcpu_id)
 {
-	return plat_info->lapic_ids[pcpu_id];
+	return plat_info->hw.lapic_ids[pcpu_id];
 }
 
 static int
 basl_fwrite_madt(FILE *fp, struct vmctx *ctx)
 {
 	int i;
-	struct acrn_vm_config vm_cfg;
-	struct platform_info plat_info;
+	struct acrn_vm_config_header vm_cfg;
+	struct acrn_platform_info plat_info;
 	uint64_t dm_cpu_bitmask, hv_cpu_bitmask, guest_pcpu_bitmask;
 
 	if (vm_get_config(ctx, &vm_cfg, &plat_info)) {
@@ -339,9 +339,9 @@ basl_fwrite_madt(FILE *fp, struct vmctx *ctx)
 			return -1;
 		}
 
-		assert(pcpu_id < MAX_PLATFORM_LAPIC_IDS);
-		if (pcpu_id >= MAX_PLATFORM_LAPIC_IDS) {
-			pr_err("%s,Err: pcpu id %u should be less than MAX_PLATFORM_LAPIC_IDS.\n", __func__, pcpu_id);
+		assert(pcpu_id < ACRN_PLATFORM_LAPIC_IDS_MAX);
+		if (pcpu_id >= ACRN_PLATFORM_LAPIC_IDS_MAX) {
+			pr_err("%s,Err: pcpu id %u should be less than ACRN_PLATFORM_LAPIC_IDS_MAX.\n", __func__, pcpu_id);
 			return -1;
 		}
 
diff --git a/devicemodel/hw/platform/acpi/rtct.c b/devicemodel/hw/platform/acpi/rtct.c
index 744b7ffee..169319674 100644
--- a/devicemodel/hw/platform/acpi/rtct.c
+++ b/devicemodel/hw/platform/acpi/rtct.c
@@ -39,7 +39,7 @@
 static uint16_t guest_vcpu_num;
 static uint32_t guest_l2_cat_shift;
 static uint32_t guest_l3_cat_shift;
-static uint32_t guest_lapicid_tbl[MAX_PLATFORM_LAPIC_IDS];
+static uint32_t guest_lapicid_tbl[ACRN_PLATFORM_LAPIC_IDS_MAX];
 
 static uint64_t software_sram_base_hpa;
 static uint64_t software_sram_size;
@@ -281,7 +281,7 @@ static int init_vrtct_v1(struct acpi_table_hdr *vrtct, struct acpi_table_hdr *na
 	struct rtct_entry *entry;
 	struct rtct_entry_data_ssram *ssram;
 	struct rtct_entry_data_mem_hi_latency *mem_hi;
-	uint32_t lapicids[MAX_PLATFORM_LAPIC_IDS];
+	uint32_t lapicids[ACRN_PLATFORM_LAPIC_IDS_MAX];
 
 	foreach_rtct_entry(native_rtct, entry) {
 		if (entry->type == RTCT_ENTRY_TYPE_SSRAM) {
@@ -289,7 +289,7 @@ static int init_vrtct_v1(struct acpi_table_hdr *vrtct, struct acpi_table_hdr *na
 			plapic_num = (entry->size - RTCT_SSRAM_HEADER_SIZE) / sizeof(uint32_t);
 			ssram =  (struct rtct_entry_data_ssram *)entry->data;
 
-			memset(lapicids, 0, sizeof(lapicids[MAX_PLATFORM_LAPIC_IDS]));
+			memset(lapicids, 0, sizeof(lapicids[ACRN_PLATFORM_LAPIC_IDS_MAX]));
 			vlapic_num = 0;
 			for (i = 0; i < plapic_num; i++) {
 				if (is_pcpu_assigned_to_guest(ssram->apic_id_tbl[i])) {
@@ -391,7 +391,7 @@ static int passthru_rtct_to_guest(struct acpi_table_hdr *vrtct, struct acpi_tabl
 	return  0;
 }
 
-static int init_guest_lapicid_tbl(struct platform_info *platform_info, uint64_t guest_pcpu_bitmask)
+static int init_guest_lapicid_tbl(struct acrn_platform_info *platform_info, uint64_t guest_pcpu_bitmask)
 {
 	int pcpu_id = 0, vcpu_id = 0;
 
@@ -440,11 +440,11 @@ uint64_t get_software_sram_size(void)
 uint8_t *build_vrtct(struct vmctx *ctx, void *cfg)
 {
 #define PTCT_BUF_SIZE 4096
-	struct acrn_vm_config vm_cfg;
+	struct acrn_vm_config_header vm_cfg;
 	struct acpi_table_hdr *rtct_cfg, *vrtct = NULL;
 	uint64_t dm_cpu_bitmask, hv_cpu_bitmask, guest_pcpu_bitmask;
 	uint32_t gpu_rsvmem_base_gpa = 0;
-	struct platform_info platform_info;
+	struct acrn_platform_info platform_info;
 
 	if ((cfg == NULL) || (ctx == NULL))
 		return NULL;
@@ -464,7 +464,7 @@ uint8_t *build_vrtct(struct vmctx *ctx, void *cfg)
 		pr_err("%s, get VM configuration fail.\n", __func__);
 		goto error;
 	}
-	assert(platform_info.cpu_num <= MAX_PLATFORM_LAPIC_IDS);
+	assert(platform_info.hw.cpu_num <= ACRN_PLATFORM_LAPIC_IDS_MAX);
 
 	/*
 	 * pCPU bitmask of VM is configured in hypervisor by default but can be
@@ -492,8 +492,8 @@ uint8_t *build_vrtct(struct vmctx *ctx, void *cfg)
 		__func__, dm_cpu_bitmask, hv_cpu_bitmask, guest_pcpu_bitmask);
 
 	guest_vcpu_num = bitmap_weight(guest_pcpu_bitmask);
-	guest_l2_cat_shift = platform_info.l2_cat_shift;
-	guest_l3_cat_shift = platform_info.l3_cat_shift;
+	guest_l2_cat_shift = platform_info.hw.l2_cat_shift;
+	guest_l3_cat_shift = platform_info.hw.l3_cat_shift;
 
 	if (init_guest_lapicid_tbl(&platform_info, guest_pcpu_bitmask) < 0) {
 		pr_err("%s,init guest lapicid table fail.\n", __func__);
diff --git a/devicemodel/include/acpi.h b/devicemodel/include/acpi.h
index 71ca48b25..4bf14b77e 100644
--- a/devicemodel/include/acpi.h
+++ b/devicemodel/include/acpi.h
@@ -86,6 +86,6 @@ void	power_button_init(struct vmctx *ctx);
 void	power_button_deinit(struct vmctx *ctx);
 
 int pcpuid_from_vcpuid(uint64_t guest_pcpu_bitmask, int vcpu_id);
-int lapicid_from_pcpuid(struct platform_info *plat_info, int pcpu_id);
+int lapicid_from_pcpuid(struct acrn_platform_info *plat_info, int pcpu_id);
 
 #endif /* _ACPI_H_ */
diff --git a/devicemodel/include/public/hsm_ioctl_defs.h b/devicemodel/include/public/hsm_ioctl_defs.h
index 59ac23884..380a8d129 100644
--- a/devicemodel/include/public/hsm_ioctl_defs.h
+++ b/devicemodel/include/public/hsm_ioctl_defs.h
@@ -52,18 +52,25 @@
 #ifndef	_VHM_IOCTL_DEFS_H_
 #define	_VHM_IOCTL_DEFS_H_
 
+#include <linux/types.h>
+
 /* Commmon structures for ACRN/HSM/DM */
 #include "acrn_common.h"
 
+/* The ioctl type, documented in ioctl-number.rst */
+#define ACRN_IOCTL_TYPE			0xA2
+
 /*
  * Commmon IOCTL ID defination for HSM/DM
  */
 #define _IC_ID(x, y) (((x)<<24)|(y))
 #define IC_ID 0x43UL
 
-/* General */
-#define IC_ID_GEN_BASE                  0x0UL
-#define IC_GET_PLATFORM_INFO           _IC_ID(IC_ID, IC_ID_GEN_BASE + 0x03)
+/*
+ * Common IOCTL IDs definition for ACRN userspace
+ */
+#define ACRN_IOCTL_GET_PLATFORM_INFO	\
+	_IOR(ACRN_IOCTL_TYPE, 0x03, struct acrn_platform_info)
 
 /* VM management */
 #define IC_ID_VM_BASE                  0x10UL
@@ -280,96 +287,47 @@ struct ioreq_notify {
 	uint32_t vcpu;
 };
 
-enum acrn_vm_load_order {
-	PRE_LAUNCHED_VM = 0,
-	SOS_VM,
-	POST_LAUNCHED_VM,
-	MAX_LOAD_ORDER
+#define ACRN_PLATFORM_LAPIC_IDS_MAX	64
+/**
+ * struct acrn_platform_info - Information of a platform from hypervisor
+ * @hw.cpu_num:			Physical CPU number of the platform
+ * @hw.version:			Version of this structure
+ * @hw.l2_cat_shift:		Order of the number of threads sharing L2 cache
+ * @hw.l3_cat_shift:		Order of the number of threads sharing L3 cache
+ * @hw.lapic_ids:		IDs of LAPICs of all threads
+ * @hw.reserved:		Reserved for alignment and should be 0
+ * @sw.max_vcpus_per_vm:	Maximum number of vCPU of a VM
+ * @sw.max_vms:			Maximum number of VM
+ * @sw.vm_config_size:		Size of configuration of a VM
+ * @sw.vm_configss_addr:	Memory address which user space provided to
+ *				store the VM configurations
+ * @sw.max_kata_containers:	Maximum number of VM for Kata containers
+ * @sw.reserved:		Reserved for alignment and should be 0
+ *
+ * If vm_configs_addr is provided, the driver uses a bounce buffer (kmalloced
+ * for continuous memory region) to fetch VM configurations data from the
+ * hypervisor.
+ */
+struct acrn_platform_info {
+	struct {
+		__u16	cpu_num;
+		__u16	version;
+		__u32	l2_cat_shift;
+		__u32	l3_cat_shift;
+		__u8	lapic_ids[ACRN_PLATFORM_LAPIC_IDS_MAX];
+		__u8	reserved[52];
+	} hw;
+
+	struct {
+		__u16	max_vcpus_per_vm;
+		__u16	max_vms;
+		__u32	vm_config_size;
+		void	*vm_configs_addr;
+		__u64	max_kata_containers;
+		__u8	reserved[104];
+	} sw;
 };
 
-/**
- * @brief data structure to parse configuration data of VM.
- */
-struct acrn_vm_config {
-#define MAX_VM_OS_NAME_LEN      32U
-	enum acrn_vm_load_order load_order;
-	char name[MAX_VM_OS_NAME_LEN];
-	const uint8_t uuid[16];
-	uint8_t reserved[2];
-	uint8_t severity;
-	uint64_t cpu_affinity;
-	uint64_t guest_flags;
-	/*
-	 * Ignore other members that are hypervisor specific, actual size
-	 * of current structure can be parsed by 'vm_config_entry_size' of
-	 * 'struct platform_info'.
-	 */
-} __aligned(8);
-
-/**
- * @brief data structure to track VHM platform information
- */
-struct platform_info {
-	/** Hardware Information */
-	/** Physical CPU number */
-	uint16_t cpu_num;
-
-	/** version of this structure */
-	uint16_t version;
-
-	uint32_t l2_cat_shift;
-	uint32_t l3_cat_shift;
-
-	#define MAX_PLATFORM_LAPIC_IDS 64U
-	/** pLAPIC ID list */
-	uint8_t lapic_ids[MAX_PLATFORM_LAPIC_IDS];
-
-	/**
-	 * sizeof(uint8_t reserved0[]) + sizeof(l2_cat_shift)
-	 * + sizeof(l3_cat_shift) + sizeof(uint8_t lapic_ids[]) = 124
-	 *
-	 * Note:
-	 * 1. DM needs to use the same logic as hypervisor to calculate vLAPIC IDs
-	 * based on physical APIC IDs and CPU affinity setting.
-	 *
-	 * 2. Can only support at most 116 cores. And it assumes LAPIC ID is 8bits
-	 * (X2APIC mode supports 32 bits)
-	 */
-	uint8_t reserved0[116U - MAX_PLATFORM_LAPIC_IDS];
-
-	/** Configuration Information */
-	/** Maximum vCPU number for one VM. */
-	uint16_t max_vcpus_per_vm;
-
-	/** Maximum Kata container number in SOS VM */
-	uint8_t max_kata_containers;
-
-	uint8_t reserved1[7];
-
-	/** Number of configured VMs */
-	uint16_t max_vms;
-
-	/**
-	 * The size of acrn_vm_config is various on different platforms.
-	 * This is the size of this struct which is used by the caller
-	 * to parse the vm_configs array.
-	 */
-	uint32_t vm_config_entry_size;
-
-	/**
-	 * Address to an array of struct acrn_vm_config, containing all
-	 * the configurations of all VMs. VHM treats it as an opague data
-	 * structure.
-	 *
-	 * The size of one array element is vm_config_entry_size while
-	 * the number of elements is max_vms.
-	 */
-	uint64_t vm_configs_addr;
-
-	/** Align the size of Configuration info to 128Bytes. */
-	uint8_t reserved2[104];
-} __aligned(8);
-
 struct acrn_ioeventfd {
 #define ACRN_IOEVENTFD_FLAG_PIO		0x01
 #define ACRN_IOEVENTFD_FLAG_DATAMATCH	0x02
diff --git a/devicemodel/include/vmmapi.h b/devicemodel/include/vmmapi.h
index 86343ecc9..2a4b543e6 100644
--- a/devicemodel/include/vmmapi.h
+++ b/devicemodel/include/vmmapi.h
@@ -151,5 +151,6 @@ void	vm_reset_watchdog(struct vmctx *ctx);
 
 int	vm_ioeventfd(struct vmctx *ctx, struct acrn_ioeventfd *args);
 int	vm_irqfd(struct vmctx *ctx, struct acrn_irqfd *args);
-int	vm_get_config(struct vmctx *ctx, struct acrn_vm_config *vm_cfg, struct platform_info *plat_info);
+int	vm_get_config(struct vmctx *ctx, struct acrn_vm_config_header *vm_cfg,
+		      struct acrn_platform_info *plat_info);
 #endif	/* _VMMAPI_H_ */
diff --git a/hypervisor/include/arch/x86/asm/vm_config.h b/hypervisor/include/arch/x86/asm/vm_config.h
index d179bdd90..016dc0401 100644
--- a/hypervisor/include/arch/x86/asm/vm_config.h
+++ b/hypervisor/include/arch/x86/asm/vm_config.h
@@ -65,21 +65,6 @@
 				.uuid = KATA_VM_UUID##idx,	\
 				.severity = SEVERITY_STANDARD_VM
 
-/*
- * PRE_LAUNCHED_VM is launched by ACRN hypervisor, with LAPIC_PT;
- * SOS_VM is launched by ACRN hypervisor, without LAPIC_PT;
- * POST_LAUNCHED_VM is launched by ACRN devicemodel, with/without LAPIC_PT depends on usecases.
- *
- * Assumption: vm_configs array is completely initialized w.r.t. load_order member of
- * 		acrn_vm_config for all the VMs.
- */
-enum acrn_vm_load_order {
-	PRE_LAUNCHED_VM = 0,
-	SOS_VM,
-	POST_LAUNCHED_VM,	/* Launched by Devicemodel in SOS_VM */
-	MAX_LOAD_ORDER
-};
-
 /* ACRN guest severity */
 enum acrn_vm_severity {
 	SEVERITY_SAFETY_VM = 0x40U,
diff --git a/hypervisor/include/public/acrn_common.h b/hypervisor/include/public/acrn_common.h
index ae4a26771..b165cb73a 100644
--- a/hypervisor/include/public/acrn_common.h
+++ b/hypervisor/include/public/acrn_common.h
@@ -663,6 +663,37 @@ struct acrn_intr_monitor {
 #define INTR_CMD_GET_DATA 0U
 #define INTR_CMD_DELAY_INT 1U
 
+/*
+ * PRE_LAUNCHED_VM is launched by ACRN hypervisor, with LAPIC_PT;
+ * SOS_VM is launched by ACRN hypervisor, without LAPIC_PT;
+ * POST_LAUNCHED_VM is launched by ACRN devicemodel, with/without LAPIC_PT depends on usecases.
+ *
+ * Assumption: vm_configs array is completely initialized w.r.t. load_order member of
+ * 		acrn_vm_config for all the VMs.
+ */
+enum acrn_vm_load_order {
+	PRE_LAUNCHED_VM = 0,
+	SOS_VM,
+	POST_LAUNCHED_VM,	/* Launched by Devicemodel in SOS_VM */
+	MAX_LOAD_ORDER
+};
+
+#define MAX_VM_OS_NAME_LEN      32U
+
+struct acrn_vm_config_header {
+       enum acrn_vm_load_order load_order;
+       char name[MAX_VM_OS_NAME_LEN];
+       const uint8_t uuid[16];
+       uint8_t reserved[2];
+       uint8_t severity;
+       uint64_t cpu_affinity;
+       uint64_t guest_flags;
+       /*
+        * The following are hv-specific members and are thus opaque.
+        * vm_config_entry_size determines the real size of this structure.
+        */
+} __aligned(8);
+
 /**
  * @brief Info to configure virtual root port
  *