diff --git a/hypervisor/arch/x86/guest/vm.c b/hypervisor/arch/x86/guest/vm.c
index 6f796be65..4898f8101 100644
--- a/hypervisor/arch/x86/guest/vm.c
+++ b/hypervisor/arch/x86/guest/vm.c
@@ -110,6 +110,8 @@ struct acrn_vm *get_vm_from_vmid(uint16_t vm_id)
 /* return a pointer to the virtual machine structure of SOS VM */
 struct acrn_vm *get_sos_vm(void)
 {
+	ASSERT(sos_vm_ptr != NULL, "sos_vm_ptr is NULL");
+
 	return sos_vm_ptr;
 }
 
diff --git a/hypervisor/dm/vpci/msi.c b/hypervisor/dm/vpci/msi.c
index 44580222c..e8b9e9900 100644
--- a/hypervisor/dm/vpci/msi.c
+++ b/hypervisor/dm/vpci/msi.c
@@ -167,22 +167,13 @@ int32_t vmsi_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, ui
 	return ret;
 }
 
-int32_t vmsi_deinit(const struct pci_vdev *vdev)
+void vmsi_deinit(const struct pci_vdev *vdev)
 {
 	if (has_msi_cap(vdev)) {
 		ptirq_remove_msix_remapping(vdev->vpci->vm, vdev->vbdf.value, 1U);
 	}
-
-	return 0;
 }
 
-const struct pci_vdev_ops pci_ops_vdev_msi = {
-	.init = vmsi_init,
-	.deinit = vmsi_deinit,
-	.cfgwrite = vmsi_cfgwrite,
-	.cfgread = vmsi_cfgread,
-};
-
 /* Read a uint32_t from buffer (little endian) */
 static uint32_t buf_read32(const uint8_t buf[])
 {
@@ -198,7 +189,7 @@ static void buf_write32(uint8_t buf[], uint32_t val)
 	buf[3] = (uint8_t)((val >> 24U) & 0xFFU);
 }
 
-int32_t vmsi_init(struct pci_vdev *vdev)
+void vmsi_init(struct pci_vdev *vdev)
 {
 	struct pci_pdev *pdev = vdev->pdev;
 	uint32_t val;
@@ -216,7 +207,5 @@ int32_t vmsi_init(struct pci_vdev *vdev)
 
 		buf_write32(&vdev->cfgdata.data_8[pdev->msi.capoff], val);
 	}
-
-	return 0;
 }
 
diff --git a/hypervisor/dm/vpci/msix.c b/hypervisor/dm/vpci/msix.c
index 2fe38351d..558cd79dd 100644
--- a/hypervisor/dm/vpci/msix.c
+++ b/hypervisor/dm/vpci/msix.c
@@ -328,74 +328,71 @@ static int32_t vmsix_table_mmio_access_handler(struct io_request *io_req, void *
 	return ret;
 }
 
-static int32_t vmsix_init_helper(struct pci_vdev *vdev)
+
+/**
+* @pre vdev != NULL
+* @pre vdev->pdev != NULL
+* @pre vdev->pdev->msix.table_bar < (PCI_BAR_COUNT - 1U)
+*/
+static void vmsix_init_helper(struct pci_vdev *vdev)
 {
 	uint32_t i;
 	uint64_t addr_hi, addr_lo;
 	struct pci_msix *msix = &vdev->msix;
 	struct pci_pdev *pdev = vdev->pdev;
 	struct pci_bar *bar;
-	int32_t ret;
+
+	ASSERT(vdev->pdev->msix.table_bar < (PCI_BAR_COUNT - 1U), "msix->table_bar out of range");
 
 	msix->table_bar = pdev->msix.table_bar;
 	msix->table_offset = pdev->msix.table_offset;
 	msix->table_count = pdev->msix.table_count;
 
-	if (msix->table_bar < (PCI_BAR_COUNT - 1U)) {
-		/* Mask all table entries */
-		for (i = 0U; i < msix->table_count; i++) {
-			msix->tables[i].vector_control = PCIM_MSIX_VCTRL_MASK;
-			msix->tables[i].addr = 0U;
-			msix->tables[i].data = 0U;
-		}
-
-		bar = &pdev->bar[msix->table_bar];
-		if (bar != NULL) {
-			vdev->msix.mmio_hpa = bar->base;
-			vdev->msix.mmio_gpa = sos_vm_hpa2gpa(bar->base);
-			vdev->msix.mmio_size = bar->size;
-		}
-
-		if (msix->mmio_gpa != 0U) {
-			/*
-			 * PCI Spec: a BAR may also map other usable address space that is not associated
-			 * with MSI-X structures, but it must not share any naturally aligned 4 KB
-			 * address range with one where either MSI-X structure resides.
-			 * The MSI-X Table and MSI-X PBA are permitted to co-reside within a naturally
-			 * aligned 4 KB address range.
-			 *
-			 * If PBA or others reside in the same BAR with MSI-X Table, devicemodel could
-			 * emulate them and maps these memory range at the 4KB boundary. Here, we should
-			 * make sure only intercept the minimum number of 4K pages needed for MSI-X table.
-			 */
-
-			/* The higher boundary of the 4KB aligned address range for MSI-X table */
-			addr_hi = msix->mmio_gpa + msix->table_offset + (msix->table_count * MSIX_TABLE_ENTRY_SIZE);
-			addr_hi = round_page_up(addr_hi);
-
-			/* The lower boundary of the 4KB aligned address range for MSI-X table */
-			addr_lo = round_page_down(msix->mmio_gpa + msix->table_offset);
-
-			(void)register_mmio_emulation_handler(vdev->vpci->vm, vmsix_table_mmio_access_handler,
-				addr_lo, addr_hi, vdev);
-		}
-		ret = 0;
-	} else {
-		pr_err("%s, MSI-X device (%x) invalid table BIR %d", __func__, vdev->pdev->bdf.value, msix->table_bar);
-		vdev->msix.capoff = 0U;
-	    ret = -EIO;
+	/* Mask all table entries */
+	for (i = 0U; i < msix->table_count; i++) {
+		msix->tables[i].vector_control = PCIM_MSIX_VCTRL_MASK;
+		msix->tables[i].addr = 0U;
+		msix->tables[i].data = 0U;
 	}
 
-	return ret;
+	bar = &pdev->bar[msix->table_bar];
+	if (bar != NULL) {
+		vdev->msix.mmio_hpa = bar->base;
+		vdev->msix.mmio_gpa = sos_vm_hpa2gpa(bar->base);
+		vdev->msix.mmio_size = bar->size;
+	}
+
+	if (msix->mmio_gpa != 0U) {
+		/*
+			* PCI Spec: a BAR may also map other usable address space that is not associated
+			* with MSI-X structures, but it must not share any naturally aligned 4 KB
+			* address range with one where either MSI-X structure resides.
+			* The MSI-X Table and MSI-X PBA are permitted to co-reside within a naturally
+			* aligned 4 KB address range.
+			*
+			* If PBA or others reside in the same BAR with MSI-X Table, devicemodel could
+			* emulate them and maps these memory range at the 4KB boundary. Here, we should
+			* make sure only intercept the minimum number of 4K pages needed for MSI-X table.
+			*/
+
+		/* The higher boundary of the 4KB aligned address range for MSI-X table */
+		addr_hi = msix->mmio_gpa + msix->table_offset + (msix->table_count * MSIX_TABLE_ENTRY_SIZE);
+		addr_hi = round_page_up(addr_hi);
+
+		/* The lower boundary of the 4KB aligned address range for MSI-X table */
+		addr_lo = round_page_down(msix->mmio_gpa + msix->table_offset);
+
+		(void)register_mmio_emulation_handler(vdev->vpci->vm, vmsix_table_mmio_access_handler,
+			addr_lo, addr_hi, vdev);
+	}
 }
 
 /**
  * @pre vdev != NULL
  */
-int32_t vmsix_init(struct pci_vdev *vdev)
+void vmsix_init(struct pci_vdev *vdev)
 {
 	struct pci_pdev *pdev = vdev->pdev;
-	int32_t ret = 0;
 
 	vdev->msix.capoff = pdev->msix.capoff;
 	vdev->msix.caplen = pdev->msix.caplen;
@@ -404,10 +401,8 @@ int32_t vmsix_init(struct pci_vdev *vdev)
 		(void)memcpy_s((void *)&vdev->cfgdata.data_8[pdev->msix.capoff], pdev->msix.caplen,
 			(void *)&pdev->msix.cap[0U], pdev->msix.caplen);
 
-		ret = vmsix_init_helper(vdev);
+		vmsix_init_helper(vdev);
 	}
-
-	return ret;
 }
 
 /**
@@ -415,20 +410,11 @@ int32_t vmsix_init(struct pci_vdev *vdev)
  * @pre vdev->vpci != NULL
  * @pre vdev->vpci->vm != NULL
  */
-int32_t vmsix_deinit(const struct pci_vdev *vdev)
+void vmsix_deinit(const struct pci_vdev *vdev)
 {
 	if (has_msix_cap(vdev)) {
 		if (vdev->msix.table_count != 0U) {
 			ptirq_remove_msix_remapping(vdev->vpci->vm, vdev->vbdf.value, vdev->msix.table_count);
 		}
 	}
-
-	return 0;
 }
-
-const struct pci_vdev_ops pci_ops_vdev_msix = {
-	.init = vmsix_init,
-	.deinit = vmsix_deinit,
-	.cfgwrite = vmsix_cfgwrite,
-	.cfgread = vmsix_cfgread,
-};
diff --git a/hypervisor/dm/vpci/pci_priv.h b/hypervisor/dm/vpci/pci_priv.h
index e2f03bc6e..0bcd289c9 100644
--- a/hypervisor/dm/vpci/pci_priv.h
+++ b/hypervisor/dm/vpci/pci_priv.h
@@ -81,25 +81,20 @@ int32_t vdev_pt_deinit(const struct pci_vdev *vdev);
 
 #else
 extern const struct vpci_ops sharing_mode_vpci_ops;
-extern const struct pci_vdev_ops pci_ops_vdev_msi;
-extern const struct pci_vdev_ops pci_ops_vdev_msix;
 
-int32_t vmsi_init(struct pci_vdev *vdev);
+void vmsi_init(struct pci_vdev *vdev);
 int32_t vmsi_cfgread(const struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t *val);
 int32_t vmsi_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val);
-int32_t vmsi_deinit(const struct pci_vdev *vdev);
-
-int32_t vmsix_init(struct pci_vdev *vdev);
+void vmsi_deinit(const struct pci_vdev *vdev);
+void vmsix_init(struct pci_vdev *vdev);
 int32_t vmsix_cfgread(const struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t *val);
 int32_t vmsix_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val);
-int32_t vmsix_deinit(const struct pci_vdev *vdev);
+void vmsix_deinit(const struct pci_vdev *vdev);
 #endif
 
 uint32_t pci_vdev_read_cfg(const struct pci_vdev *vdev, uint32_t offset, uint32_t bytes);
 void pci_vdev_write_cfg(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val);
 
-void add_vdev_handler(struct pci_vdev *vdev, const struct pci_vdev_ops *ops);
-
 struct pci_vdev *pci_find_vdev_by_vbdf(const struct acrn_vpci *vpci, union pci_bdf vbdf);
 
 struct pci_vdev *pci_find_vdev_by_pbdf(const struct acrn_vpci *vpci, union pci_bdf pbdf);
diff --git a/hypervisor/dm/vpci/sharing_mode.c b/hypervisor/dm/vpci/sharing_mode.c
index 4a67924e3..5e35bb288 100644
--- a/hypervisor/dm/vpci/sharing_mode.c
+++ b/hypervisor/dm/vpci/sharing_mode.c
@@ -33,31 +33,19 @@
 #include "pci_priv.h"
 
 
-/**
- * @pre vpci != NULL
- */
 static struct pci_vdev *sharing_mode_find_vdev_sos(union pci_bdf pbdf)
 {
 	struct acrn_vm *vm;
-	struct acrn_vpci *vpci;
-	struct pci_vdev *vdev = NULL;
 
 	vm = get_sos_vm();
-	if (vm != NULL) {
-		vpci = &vm->vpci;
-		vdev = pci_find_vdev_by_pbdf(vpci, pbdf);
-	}
 
-	return vdev;
+	return pci_find_vdev_by_pbdf(&vm->vpci, pbdf);
 }
 
-
 static void sharing_mode_cfgread(__unused struct acrn_vpci *vpci, union pci_bdf bdf,
 	uint32_t offset, uint32_t bytes, uint32_t *val)
 {
 	struct pci_vdev *vdev;
-	bool handled = false;
-	uint32_t i;
 
 	vdev = sharing_mode_find_vdev_sos(bdf);
 
@@ -65,16 +53,10 @@ static void sharing_mode_cfgread(__unused struct acrn_vpci *vpci, union pci_bdf
 	if ((vdev == NULL) || ((bytes != 1U) && (bytes != 2U) && (bytes != 4U))) {
 		*val = ~0U;
 	} else {
-		for (i = 0U; (i < vdev->nr_ops) && (!handled); i++) {
-			if (vdev->ops[i].cfgread != NULL) {
-				if (vdev->ops[i].cfgread(vdev, offset, bytes, val) == 0) {
-					handled = true;
-				}
-			}
-		}
-
-		/* Not handled by any handlers, passthru to physical device */
-		if (!handled) {
+		if ((vmsi_cfgread(vdev, offset, bytes, val) != 0)
+			&& (vmsix_cfgread(vdev, offset, bytes, val) != 0)
+			) {
+			/* Not handled by any handlers, passthru to physical device */
 			*val = pci_pdev_read_cfg(vdev->pdev->bdf, offset, bytes);
 		}
 	}
@@ -84,22 +66,14 @@ static void sharing_mode_cfgwrite(__unused struct acrn_vpci *vpci, union pci_bdf
 	uint32_t offset, uint32_t bytes, uint32_t val)
 {
 	struct pci_vdev *vdev;
-	bool handled = false;
-	uint32_t i;
 
 	if ((bytes == 1U) || (bytes == 2U) || (bytes == 4U)) {
 		vdev = sharing_mode_find_vdev_sos(bdf);
 		if (vdev != NULL) {
-			for (i = 0U; (i < vdev->nr_ops) && (!handled); i++) {
-				if (vdev->ops[i].cfgwrite != NULL) {
-					if (vdev->ops[i].cfgwrite(vdev, offset, bytes, val) == 0) {
-						handled = true;
-					}
-				}
-			}
-
-			/* Not handled by any handlers, passthru to physical device */
-			if (!handled) {
+			if ((vmsi_cfgwrite(vdev, offset, bytes, val) != 0)
+				&& (vmsix_cfgwrite(vdev, offset, bytes, val) != 0)
+				) {
+				/* Not handled by any handlers, passthru to physical device */
 				pci_pdev_write_cfg(vdev->pdev->bdf, offset, bytes, val);
 			}
 		}
@@ -107,15 +81,14 @@ static void sharing_mode_cfgwrite(__unused struct acrn_vpci *vpci, union pci_bdf
 }
 
 /**
+ * @pre pdev != NULL
  * @pre vm != NULL
- * @pre pdev_ref != NULL
- * @pre vm->vpci->pci_vdev_cnt <= CONFIG_MAX_PCI_DEV_NUM
- * @pre vdev != NULL
+ * @pre vm->vpci.pci_vdev_cnt <= CONFIG_MAX_PCI_DEV_NUM
  */
-static struct pci_vdev *alloc_pci_vdev(const struct acrn_vm *vm, struct pci_pdev *pdev_ref)
+static void init_vdev_for_pdev(struct pci_pdev *pdev, const void *vm)
 {
 	struct pci_vdev *vdev = NULL;
-	struct acrn_vpci *vpci = (struct acrn_vpci *)&(vm->vpci);
+	struct acrn_vpci *vpci = &(((struct acrn_vm *)vm)->vpci);
 
 	if (vpci->pci_vdev_cnt < CONFIG_MAX_PCI_DEV_NUM) {
 		vdev = &vpci->pci_vdevs[vpci->pci_vdev_cnt];
@@ -123,35 +96,17 @@ static struct pci_vdev *alloc_pci_vdev(const struct acrn_vm *vm, struct pci_pdev
 
 		vdev->vpci = vpci;
 		/* vbdf equals to pbdf otherwise remapped */
-		vdev->vbdf = pdev_ref->bdf;
-		vdev->pdev = pdev_ref;
-	}
+		vdev->vbdf = pdev->bdf;
+		vdev->pdev = pdev;
 
-	return vdev;
-}
+		vmsi_init(vdev);
 
-static void init_vdev_for_pdev(struct pci_pdev *pdev, const void *cb_data)
-{
-	const struct acrn_vm *vm = (const struct acrn_vm *)cb_data;
-	struct pci_vdev *vdev;
-
-	vdev = alloc_pci_vdev(vm, pdev);
-	if (vdev != NULL) {
-		/* Assign MSI handler for configuration read and write */
-		add_vdev_handler(vdev, &pci_ops_vdev_msi);
-
-		/* Assign MSI-X handler for configuration read and write */
-		add_vdev_handler(vdev, &pci_ops_vdev_msix);
+		vmsix_init(vdev);
 	}
 }
 
-/**
- * @pre vdev != NULL
- */
 static int32_t sharing_mode_vpci_init(const struct acrn_vm *vm)
 {
-	struct pci_vdev *vdev;
-	uint32_t i, j;
 	int32_t ret = -ENODEV;
 
 	/*
@@ -161,15 +116,6 @@ static int32_t sharing_mode_vpci_init(const struct acrn_vm *vm)
 	if (is_sos_vm(vm)) {
 		/* Build up vdev array for sos_vm */
 		pci_pdev_foreach(init_vdev_for_pdev, vm);
-
-		for (i = 0U; i < vm->vpci.pci_vdev_cnt; i++) {
-			vdev = (struct pci_vdev *)&(vm->vpci.pci_vdevs[i]);
-			for (j = 0U; j < vdev->nr_ops; j++) {
-				if (vdev->ops[j].init != NULL) {
-					(void)vdev->ops[j].init(vdev);
-				}
-			}
-		}
 		ret = 0;
 	}
 
@@ -177,32 +123,22 @@ static int32_t sharing_mode_vpci_init(const struct acrn_vm *vm)
 }
 
 /**
- * @pre vdev != NULL
+ * @pre vm != NULL
+ * @pre vm->vpci.pci_vdev_cnt <= CONFIG_MAX_PCI_DEV_NUM
  */
 static void sharing_mode_vpci_deinit(const struct acrn_vm *vm)
 {
 	struct pci_vdev *vdev;
-	uint32_t i, j;
+	uint32_t i;
 
 	if (is_sos_vm(vm)) {
 		for (i = 0U; i < vm->vpci.pci_vdev_cnt; i++) {
 			vdev = (struct pci_vdev *)&(vm->vpci.pci_vdevs[i]);
-			for (j = 0U; j < vdev->nr_ops; j++) {
-				if (vdev->ops[j].deinit != NULL) {
-					(void)vdev->ops[j].deinit(vdev);
-				}
-			}
-		}
-	}
-}
 
-void add_vdev_handler(struct pci_vdev *vdev, const struct pci_vdev_ops *ops)
-{
-	if (vdev->nr_ops >= (MAX_VPCI_DEV_OPS - 1U)) {
-		pr_err("%s, adding too many handlers", __func__);
-	} else {
-		vdev->ops[vdev->nr_ops] = *ops;
-		vdev->nr_ops++;
+			vmsi_deinit(vdev);
+
+			vmsix_deinit(vdev);
+		}
 	}
 }
 
diff --git a/hypervisor/include/dm/vpci.h b/hypervisor/include/dm/vpci.h
index ad7677a4d..be4288824 100644
--- a/hypervisor/include/dm/vpci.h
+++ b/hypervisor/include/dm/vpci.h
@@ -77,11 +77,7 @@ union pci_cfgdata {
 };
 
 struct pci_vdev {
-#ifndef CONFIG_PARTITION_MODE
-#define MAX_VPCI_DEV_OPS   4U
-	struct pci_vdev_ops ops[MAX_VPCI_DEV_OPS];
-	uint32_t nr_ops;
-#else
+#ifdef CONFIG_PARTITION_MODE
 	const struct pci_vdev_ops *ops;
 #endif