diff --git a/hypervisor/arch/x86/guest/vm.c b/hypervisor/arch/x86/guest/vm.c
index bb50e8ca9..6ebe6396f 100644
--- a/hypervisor/arch/x86/guest/vm.c
+++ b/hypervisor/arch/x86/guest/vm.c
@@ -138,15 +138,12 @@ bool is_pi_capable(const struct acrn_vm *vm)
 	return (platform_caps.pi && (!is_lapic_pt_configured(vm)));
 }
 
-static struct acrn_vm *get_highest_severity_vm(void)
+struct acrn_vm *get_highest_severity_vm(bool runtime)
 {
 	uint16_t vm_id, highest_vm_id = 0U;
-	struct acrn_vm *vm = NULL;
 
 	for (vm_id = 1U; vm_id < CONFIG_MAX_VM_NUM; vm_id++) {
-		vm = get_vm_from_vmid(vm_id);
-
-		if (is_poweroff_vm(vm)) {
+		if (runtime && is_poweroff_vm(get_vm_from_vmid(vm_id))) {
 			/* If vm is non-existed or shutdown, it's not highest severity VM */
 			continue;
 		}
@@ -159,14 +156,6 @@ static struct acrn_vm *get_highest_severity_vm(void)
 	return get_vm_from_vmid(highest_vm_id);
 }
 
-/**
- * @pre vm != NULL && vm_config != NULL && vm->vmid < CONFIG_MAX_VM_NUM
- */
-bool is_highest_severity_vm(const struct acrn_vm *vm)
-{
-	return (get_highest_severity_vm() == vm);
-}
-
 /**
  * @pre vm != NULL && vm_config != NULL && vm->vmid < CONFIG_MAX_VM_NUM
  */
diff --git a/hypervisor/arch/x86/guest/vm_reset.c b/hypervisor/arch/x86/guest/vm_reset.c
index bd7fade2a..8fa532714 100644
--- a/hypervisor/arch/x86/guest/vm_reset.c
+++ b/hypervisor/arch/x86/guest/vm_reset.c
@@ -84,7 +84,7 @@ static bool handle_common_reset_reg_write(struct acrn_vm *vm, bool reset)
 	bool ret = true;
 
 	if (reset) {
-		if (is_highest_severity_vm(vm)) {
+		if (get_highest_severity_vm(true) == vm) {
 			reset_host();
 		} else if (is_postlaunched_vm(vm)) {
 			/* re-inject to DM */
diff --git a/hypervisor/dm/vpci/vpci.c b/hypervisor/dm/vpci/vpci.c
index d7ed33307..7cbf1172b 100644
--- a/hypervisor/dm/vpci/vpci.c
+++ b/hypervisor/dm/vpci/vpci.c
@@ -441,6 +441,7 @@ static void read_cfg_header(const struct pci_vdev *vdev,
 			*val = ~0U;
 		}
 	} else {
+		/* ToDo: add cfg_hdr_perm for Type 1 device */
 		if (bitmap32_test(((uint16_t)offset) >> 2U, &cfg_hdr_perm.pt_mask)) {
 			*val = pci_pdev_read_cfg(vdev->pdev->bdf, offset, bytes);
 
@@ -478,6 +479,7 @@ static void write_cfg_header(struct pci_vdev *vdev,
 			}
 		}
 
+		/* ToDo: add cfg_hdr_perm for Type 1 device */
 		if (!bitmap32_test(((uint16_t)offset) >> 2U, &cfg_hdr_perm.ro_mask)) {
 			if (bitmap32_test(((uint16_t)offset) >> 2U, &cfg_hdr_perm.pt_mask)) {
 				pci_pdev_write_cfg(vdev->pdev->bdf, offset, bytes, val);
@@ -624,12 +626,16 @@ struct pci_vdev *vpci_init_vdev(struct acrn_vpci *vpci, struct acrn_vm_pci_dev_c
 	if (dev_config->vdev_ops != NULL) {
 		vdev->vdev_ops = dev_config->vdev_ops;
 	} else {
-		if (is_bridge(vdev->pdev)) {
-			vdev->vdev_ops = &vpci_bridge_ops;
-		} else if (is_host_bridge(vdev->pdev)) {
-			vdev->vdev_ops = &vhostbridge_ops;
-		} else {
+		if (get_highest_severity_vm(false) == vpci2vm(vpci)) {
 			vdev->vdev_ops = &pci_pt_dev_ops;
+		} else {
+			if (is_bridge(vdev->pdev)) {
+				vdev->vdev_ops = &vpci_bridge_ops;
+			} else if (is_host_bridge(vdev->pdev)) {
+				vdev->vdev_ops = &vhostbridge_ops;
+			} else {
+				vdev->vdev_ops = &pci_pt_dev_ops;
+			}
 		}
 
 		ASSERT(dev_config->emu_type == PCI_DEV_TYPE_PTDEV,
@@ -682,7 +688,8 @@ int32_t vpci_assign_pcidev(struct acrn_vm *tgt_vm, struct acrn_assign_pcidev *pc
 	 * For now, we don't support assignment of PF to a UOS.
 	 */
 	if ((vdev_in_sos != NULL) && (vdev_in_sos->user == vdev_in_sos) &&
-			(vdev_in_sos->pdev != NULL) && (!has_sriov_cap(vdev_in_sos))) {
+			(vdev_in_sos->pdev != NULL) && (!has_sriov_cap(vdev_in_sos)) &&
+			!is_host_bridge(vdev_in_sos->pdev) && !is_bridge(vdev_in_sos->pdev)) {
 		/* ToDo: Each PT device must support one type reset */
 		if (!vdev_in_sos->pdev->has_pm_reset && !vdev_in_sos->pdev->has_flr &&
 				!vdev_in_sos->pdev->has_af_flr) {
diff --git a/hypervisor/hw/pci.c b/hypervisor/hw/pci.c
index e0f891655..12c67fe7b 100644
--- a/hypervisor/hw/pci.c
+++ b/hypervisor/hw/pci.c
@@ -229,7 +229,7 @@ bool pdev_need_bar_restore(const struct pci_pdev *pdev)
 	bool need_restore = false;
 	uint32_t idx, bar;
 
-	for (idx = 0U; idx < PCI_STD_NUM_BARS; idx++) {
+	for (idx = 0U; idx < pdev->nr_bars; idx++) {
 		bar = pci_pdev_read_cfg(pdev->bdf, pci_bar_offset(idx), 4U);
 		if (bar != pdev->bars[idx]) {
 			need_restore = true;
@@ -244,7 +244,7 @@ static inline void pdev_save_bar(struct pci_pdev *pdev)
 {
 	uint32_t idx;
 
-	for (idx = 0U; idx < PCI_STD_NUM_BARS; idx++) {
+	for (idx = 0U; idx < pdev->nr_bars; idx++) {
 		pdev->bars[idx] = pci_pdev_read_cfg(pdev->bdf, pci_bar_offset(idx), 4U);
 	}
 }
@@ -253,7 +253,7 @@ void pdev_restore_bar(const struct pci_pdev *pdev)
 {
 	uint32_t idx;
 
-	for (idx = 0U; idx < PCI_STD_NUM_BARS; idx++) {
+	for (idx = 0U; idx < pdev->nr_bars; idx++) {
 		pci_pdev_write_cfg(pdev->bdf, pci_bar_offset(idx), 4U, pdev->bars[idx]);
 	}
 }
diff --git a/hypervisor/include/arch/x86/guest/vm.h b/hypervisor/include/arch/x86/guest/vm.h
index 6f80fbbf9..b65ce04b7 100644
--- a/hypervisor/include/arch/x86/guest/vm.h
+++ b/hypervisor/include/arch/x86/guest/vm.h
@@ -254,7 +254,7 @@ bool is_lapic_pt_configured(const struct acrn_vm *vm);
 bool is_rt_vm(const struct acrn_vm *vm);
 bool is_pi_capable(const struct acrn_vm *vm);
 bool has_rt_vm(void);
-bool is_highest_severity_vm(const struct acrn_vm *vm);
+struct acrn_vm *get_highest_severity_vm(bool runtime);
 bool vm_hide_mtrr(const struct acrn_vm *vm);
 void update_vm_vlapic_state(struct acrn_vm *vm);
 enum vm_vlapic_state check_vm_vlapic_state(const struct acrn_vm *vm);