vfio: extract setup logic out of resource mapping

The setup logic access the global vfio_cfg variable that will be moved in the
following commits. We need to separate all accesses to this variable to a
general code.

Signed-off-by: Jan Viktorin <viktorin@rehivetech.com>

diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
index c2ff465..2792c23 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
@@ -411,37 +411,22 @@ clear_current_group(void)
        vfio_cfg.vfio_groups[vfio_cfg.vfio_group_idx].fd = -1;
 }
 
-
-/*
- * map the PCI resources of a PCI device in virtual memory (VFIO version).
- * primary and secondary processes follow almost exactly the same path
+/**
+ * Setup vfio_cfg for the device indentified by its address. It discovers
+ * the configured I/O MMU groups or sets a new one for the device. If a new
+ * groups is assigned, the DMA mapping is performed.
+ * Returns 0 on success, a negative value on failure and a positive value in
+ * case the given device cannot be managed this way.
  */
-int
-pci_vfio_map_resource(struct rte_pci_device *dev)
+static int pci_vfio_setup_device(const char *pci_addr, int *vfio_dev_fd,
+               struct vfio_device_info *device_info)
 {
        struct vfio_group_status group_status = {
                        .argsz = sizeof(group_status)
        };
-       struct vfio_device_info device_info = { .argsz = sizeof(device_info) };
-       int vfio_group_fd, vfio_dev_fd;
+       int vfio_group_fd;
        int iommu_group_no;
-       char pci_addr[PATH_MAX] = {0};
-       struct rte_pci_addr *loc = &dev->addr;
-       int i, ret, msix_bar;
-       struct mapped_pci_resource *vfio_res = NULL;
-       struct mapped_pci_res_list *vfio_res_list = RTE_TAILQ_CAST(rte_vfio_tailq.head, mapped_pci_res_list);
-
-       struct pci_map *maps;
-       uint32_t msix_table_offset = 0;
-       uint32_t msix_table_size = 0;
-       uint32_t ioport_bar;
-
-       dev->intr_handle.fd = -1;
-       dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
-
-       /* store PCI address string */
-       snprintf(pci_addr, sizeof(pci_addr), PCI_PRI_FMT,
-                       loc->domain, loc->bus, loc->devid, loc->function);
+       int ret;
 
        /* get group number */
        ret = pci_vfio_get_group_no(pci_addr, &iommu_group_no);
@@ -476,8 +461,8 @@ pci_vfio_map_resource(struct rte_pci_device *dev)
        }
 
        /*
-        * at this point, we know at least one port on this device is bound to VFIO,
-        * so we can proceed to try and set this particular port up
+        * at this point, we know that this group is viable (meaning, all devices
+        * are either bound to VFIO or not bound to anything)
         */
 
        /* check if the group is viable */
@@ -495,11 +480,6 @@ pci_vfio_map_resource(struct rte_pci_device *dev)
                return -1;
        }
 
-       /*
-        * at this point, we know that this group is viable (meaning, all devices
-        * are either bound to VFIO or not bound to anything)
-        */
-
        /* check if group does not have a container yet */
        if (!(group_status.flags & VFIO_GROUP_FLAGS_CONTAINER_SET)) {
 
@@ -546,8 +526,8 @@ pci_vfio_map_resource(struct rte_pci_device *dev)
        }
 
        /* get a file descriptor for the device */
-       vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD, pci_addr);
-       if (vfio_dev_fd < 0) {
+       *vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD, pci_addr);
+       if (*vfio_dev_fd < 0) {
                /* if we cannot get a device fd, this simply means that this
                 * particular port is not bound to VFIO
                 */
@@ -557,14 +537,47 @@ pci_vfio_map_resource(struct rte_pci_device *dev)
        }
 
        /* test and setup the device */
-       ret = ioctl(vfio_dev_fd, VFIO_DEVICE_GET_INFO, &device_info);
+       ret = ioctl(*vfio_dev_fd, VFIO_DEVICE_GET_INFO, device_info);
        if (ret) {
                RTE_LOG(ERR, EAL, "  %s cannot get device info, "
                                "error %i (%s)\n", pci_addr, errno, strerror(errno));
-               close(vfio_dev_fd);
+               close(*vfio_dev_fd);
                return -1;
        }
 
+       return 0;
+}
+
+/*
+ * map the PCI resources of a PCI device in virtual memory (VFIO version).
+ * primary and secondary processes follow almost exactly the same path
+ */
+int
+pci_vfio_map_resource(struct rte_pci_device *dev)
+{
+       struct vfio_device_info device_info = { .argsz = sizeof(device_info) };
+       char pci_addr[PATH_MAX] = {0};
+       int vfio_dev_fd;
+       struct rte_pci_addr *loc = &dev->addr;
+       int i, ret, msix_bar;
+       struct mapped_pci_resource *vfio_res = NULL;
+       struct mapped_pci_res_list *vfio_res_list = RTE_TAILQ_CAST(rte_vfio_tailq.head, mapped_pci_res_list);
+
+       struct pci_map *maps;
+       uint32_t msix_table_offset = 0;
+       uint32_t msix_table_size = 0;
+       uint32_t ioport_bar;
+
+       dev->intr_handle.fd = -1;
+       dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
+
+       /* store PCI address string */
+       snprintf(pci_addr, sizeof(pci_addr), PCI_PRI_FMT,
+                       loc->domain, loc->bus, loc->devid, loc->function);
+
+       if ((ret = pci_vfio_setup_device(pci_addr, &vfio_dev_fd, &device_info)))
+               return ret;
+
        /* get MSI-X BAR, if any (we have to know where it is because we can't
         * easily mmap it when using VFIO) */
        msix_bar = -1;