hv: vpci: fix "Procedure has more than one exit point"

IEC 61508,ISO 26262 standards highly recommend single-exit rule.

Tracked-On: #861
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/dm/vpci/msi.c

@@ -118,6 +118,7 @@ static int32_t vmsi_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t by
 	bool message_changed = false;
 	bool enable;
 	uint32_t msgctrl;
+	int32_t ret = -ENODEV;
 
 	/* Writing MSI Capability Structure */
 	if (msicap_access(vdev, offset)) {
@@ -144,10 +145,10 @@ static int32_t vmsi_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t by
 			}
 		}
 
-		return 0;
+		ret = 0;
 	}
 
-	return -ENODEV;
+	return ret;
 }
 
 void populate_msi_struct(struct pci_vdev *vdev)
@@ -158,10 +159,7 @@ void populate_msi_struct(struct pci_vdev *vdev)
 	union pci_bdf pbdf = vdev->pdev.bdf;
 
 	/* Has new Capabilities list? */
-	if ((pci_pdev_read_cfg(pbdf, PCIR_STATUS, 2U) & PCIM_STATUS_CAPPRESENT) == 0U) {
+	if ((pci_pdev_read_cfg(pbdf, PCIR_STATUS, 2U) & PCIM_STATUS_CAPPRESENT) != 0U) {
-		return;
-	}
-
 		ptr = (uint8_t)pci_pdev_read_cfg(pbdf, PCIR_CAP_PTR, 1U);
 		while ((ptr != 0U) && (ptr != 0xFFU)) {
 			cap = (uint8_t)pci_pdev_read_cfg(pbdf, ptr + PCICAP_ID, 1U);
@@ -215,6 +213,7 @@ void populate_msi_struct(struct pci_vdev *vdev)
 
 			ptr = (uint8_t)pci_pdev_read_cfg(pbdf, ptr + PCICAP_NEXTPTR, 1U);
 		}
+	}
 }
 
 static int32_t vmsi_deinit(struct pci_vdev *vdev)

hypervisor/dm/vpci/msix.c

@@ -99,7 +99,7 @@ static inline void enable_disable_msix(struct pci_vdev *vdev, bool enable)
 static int32_t vmsix_remap(struct pci_vdev *vdev, bool enable)
 {
 	uint32_t index;
-	int32_t ret;
+	int32_t ret = 0;
 
 	/* disable MSI-X during configuration */
 	enable_disable_msix(vdev, false);
@@ -107,17 +107,19 @@ static int32_t vmsix_remap(struct pci_vdev *vdev, bool enable)
 	for (index = 0U; index < vdev->msix.table_count; index++) {
 		ret = vmsix_remap_entry(vdev, index, enable);
 		if (ret != 0) {
-			return ret;
+			break;
 		}
 	}
 
 	/* If MSI Enable is being set, make sure INTxDIS bit is set */
+	if (ret == 0) {
 		if (enable) {
 			enable_disable_pci_intx(vdev->pdev.bdf, false);
 		}
 		enable_disable_msix(vdev, enable);
+	}
 
-	return 0;
+	return ret;
 }
 
 /* Do MSI-X remap for one MSI-X table entry only */
@@ -263,6 +265,7 @@ static int32_t vmsix_table_mmio_access_handler(struct io_request *io_req, void *
 {
 	struct mmio_request *mmio = &io_req->reqs.mmio;
 	struct pci_vdev *vdev;
+	int32_t ret = 0;
 	uint64_t offset;
 	uint64_t hva;
 
@@ -277,9 +280,8 @@ static int32_t vmsix_table_mmio_access_handler(struct io_request *io_req, void *
 		/* Only DWORD and QWORD are permitted */
 		if ((mmio->size != 4U) && (mmio->size != 8U)) {
 			pr_err("%s, Only DWORD and QWORD are permitted", __func__);
-			return -EINVAL;
+			ret = -EINVAL;
-		}
+		} else {
-
 			stac();
 			/* MSI-X PBA and Capability Table could be in the same range */
 			if (mmio->direction == REQUEST_READ) {
@@ -299,8 +301,9 @@ static int32_t vmsix_table_mmio_access_handler(struct io_request *io_req, void *
 			}
 			clac();
 		}
+	}
 
-	return 0;
+	return ret;
 }
 
 static void decode_msix_table_bar(struct pci_vdev *vdev)

hypervisor/dm/vpci/sharing_mode.c

@@ -35,16 +35,17 @@ static struct pci_vdev sharing_mode_vdev_array[CONFIG_MAX_PCI_DEV_NUM];
 
 struct pci_vdev *sharing_mode_find_vdev(union pci_bdf pbdf)
 {
+	struct pci_vdev *vdev = NULL;
 	uint32_t i;
 
 	/* in VM0, it uses phys BDF */
 	for (i = 0U; i < num_pci_vdev; i++) {
 		if (sharing_mode_vdev_array[i].pdev.bdf.value == pbdf.value) {
-			return &sharing_mode_vdev_array[i];
+			vdev = &sharing_mode_vdev_array[i];
 		}
 	}
 
-	return NULL;
+	return vdev;
 }
 
 static void sharing_mode_cfgread(__unused struct acrn_vpci *vpci, union pci_bdf bdf,