vfio: fix workaround of BAR mapping

[dpdk.git] / drivers / bus / pci / linux / pci_vfio.c

diff --git a/drivers/bus/pci/linux/pci_vfio.c b/drivers/bus/pci/linux/pci_vfio.c
index 686386d..bb6ef7b 100644 (file)
--- a/drivers/bus/pci/linux/pci_vfio.c
+++ b/drivers/bus/pci/linux/pci_vfio.c
@@ -332,50 +332,59 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
        void *bar_addr;
        struct pci_msix_table *msix_table = &vfio_res->msix_table;
        struct pci_map *bar = &vfio_res->maps[bar_index];
+       bool again = false;
 
        if (bar->size == 0)
                /* Skip this BAR */
                return 0;
 
-       if (msix_table->bar_index == bar_index) {
-               /*
-                * VFIO will not let us map the MSI-X table,
-                * but we can map around it.
-                */
-               uint32_t table_start = msix_table->offset;
-               uint32_t table_end = table_start + msix_table->size;
-               table_end = (table_end + ~PAGE_MASK) & PAGE_MASK;
-               table_start &= PAGE_MASK;
-
-               if (table_start == 0 && table_end >= bar->size) {
-                       /* Cannot map this BAR */
-                       RTE_LOG(DEBUG, EAL, "Skipping BAR%d\n", bar_index);
-                       bar->size = 0;
-                       bar->addr = 0;
-                       return 0;
-               }
-
-               memreg[0].offset = bar->offset;
-               memreg[0].size = table_start;
-               memreg[1].offset = bar->offset + table_end;
-               memreg[1].size = bar->size - table_end;
-
-               RTE_LOG(DEBUG, EAL,
-                       "Trying to map BAR%d that contains the MSI-X "
-                       "table. Trying offsets: "
-                       "0x%04lx:0x%04lx, 0x%04lx:0x%04lx\n", bar_index,
-                       memreg[0].offset, memreg[0].size,
-                       memreg[1].offset, memreg[1].size);
-       } else {
-               memreg[0].offset = bar->offset;
-               memreg[0].size = bar->size;
-       }
-
        /* reserve the address using an inaccessible mapping */
        bar_addr = mmap(bar->addr, bar->size, 0, MAP_PRIVATE |
                        MAP_ANONYMOUS | additional_flags, -1, 0);
-       if (bar_addr != MAP_FAILED) {
+       if (bar_addr == MAP_FAILED) {
+               RTE_LOG(ERR, EAL,
+                       "Failed to create inaccessible mapping for BAR%d\n",
+                       bar_index);
+               return -1;
+       }
+
+       memreg[0].offset = bar->offset;
+       memreg[0].size = bar->size;
+       do {
                void *map_addr = NULL;
+               if (again) {
+                       /*
+                        * VFIO did not let us map the MSI-X table,
+                        * but we can map around it.
+                        */
+                       uint32_t table_start = msix_table->offset;
+                       uint32_t table_end = table_start + msix_table->size;
+                       table_end = (table_end + ~PAGE_MASK) & PAGE_MASK;
+                       table_start &= PAGE_MASK;
+
+                       if (table_start == 0 && table_end >= bar->size) {
+                               /* Cannot map this BAR */
+                               RTE_LOG(DEBUG, EAL, "Skipping BAR%d\n",
+                                               bar_index);
+                               munmap(bar_addr, bar->size);
+                               bar->size = 0;
+                               bar->addr = 0;
+                               return 0;
+                       }
+
+                       memreg[0].offset = bar->offset;
+                       memreg[0].size = table_start;
+                       memreg[1].offset = bar->offset + table_end;
+                       memreg[1].size = bar->size - table_end;
+
+                       RTE_LOG(DEBUG, EAL,
+                               "Trying to map BAR%d that contains the MSI-X "
+                               "table. Trying offsets: "
+                               "0x%04lx:0x%04lx, 0x%04lx:0x%04lx\n", bar_index,
+                               memreg[0].offset, memreg[0].size,
+                               memreg[1].offset, memreg[1].size);
+               }
+
                if (memreg[0].size) {
                        /* actual map of first part */
                        map_addr = pci_map_resource(bar_addr, vfio_dev_fd,
@@ -384,6 +393,12 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
                                                        MAP_FIXED);
                }
 
+               if (map_addr == MAP_FAILED &&
+                       msix_table->bar_index == bar_index && !again) {
+                       again = true;
+                       continue;
+               }
+
                /* if there's a second part, try to map it */
                if (map_addr != MAP_FAILED
                        && memreg[1].offset && memreg[1].size) {
@@ -404,12 +419,8 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
                                        bar_index);
                        return -1;
                }
-       } else {
-               RTE_LOG(ERR, EAL,
-                               "Failed to create inaccessible mapping for BAR%d\n",
-                               bar_index);
-               return -1;
-       }
+               break;
+       } while (again);
 
        bar->addr = bar_addr;
        return 0;