vfio: avoid enabling while the module is not loaded

When vfio module is not loaded when kernel support vfio feature,
the routine still try to open the container to get file
description.

This action is not safe, and of course got error messages:

EAL: Detected 40 lcore(s)
EAL:   unsupported IOMMU type!
EAL: VFIO support could not be initialized
EAL: Setting up memory...

This may make user confuse, this patch make it reasonable
and much more smooth to user.

Signed-off-by: Michael Qiu <michael.qiu@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
index 232fceccc7170c3103801fd805f989ed59030d9d..159cd669a2a2d8d95fe2509691fb49cb4a4d2698 100644 (file)
--- a/lib/librte_eal/common/eal_private.h
+++ b/lib/librte_eal/common/eal_private.h
@@ -203,4 +203,18 @@ int rte_eal_alarm_init(void);
  */
 int rte_eal_dev_init(void);
 
+/**
+ * Function is to check if the kernel module(like, vfio, vfio_iommu_type1,
+ * etc.) loaded.
+ *
+ * @param module_name
+ *     The module's name which need to be checked
+ *
+ * @return
+ *     -1 means some error happens(NULL pointer or open failure)
+ *     0  means the module not loaded
+ *     1  means the module loaded
+ */
+int rte_eal_check_module(const char *module_name);
+
 #endif /* _EAL_PRIVATE_H_ */

diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 2fb1acc201020e7f72f937eb889e0364c760f05c..648ef8140111d279506fd08d10bb771272e2b6d6 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -859,3 +859,30 @@ int rte_eal_has_hugepages(void)
 {
        return ! internal_config.no_hugetlbfs;
 }
+
+int
+rte_eal_check_module(const char *module_name)
+{
+       char mod_name[30]; /* Any module names can be longer than 30 bytes? */
+       int ret = 0;
+
+       if (NULL == module_name)
+               return -1;
+
+       FILE *fd = fopen("/proc/modules", "r");
+       if (NULL == fd) {
+               RTE_LOG(ERR, EAL, "Open /proc/modules failed!"
+                       " error %i (%s)\n", errno, strerror(errno));
+               return -1;
+       }
+       while (!feof(fd)) {
+               fscanf(fd, "%29s %*[^\n]", mod_name);
+               if (!strcmp(mod_name, module_name)) {
+                       ret = 1;
+                       break;
+               }
+       }
+       fclose(fd);
+
+       return ret;
+}

diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
index c1246e8dabba4c3c112c8d14ab575f6e50cdf856..20e097727f803f0d52f58d14d7fe40391fbf8bef 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
@@ -44,6 +44,7 @@
 #include <rte_tailq.h>
 #include <rte_eal_memconfig.h>
 #include <rte_malloc.h>
+#include <eal_private.h>
 
 #include "eal_filesystem.h"
 #include "eal_pci_init.h"
@@ -340,9 +341,11 @@ pci_vfio_get_container_fd(void)
                if (ret != 1) {
                        if (ret < 0)
                                RTE_LOG(ERR, EAL, "  could not get IOMMU type, "
-                                               "error %i (%s)\n", errno, strerror(errno));
+                                       "error %i (%s)\n", errno,
+                                       strerror(errno));
                        else
-                               RTE_LOG(ERR, EAL, "  unsupported IOMMU type!\n");
+                               RTE_LOG(ERR, EAL, "  unsupported IOMMU type "
+                                       "detected in VFIO\n");
                        close(vfio_container_fd);
                        return -1;
                }
@@ -783,11 +786,28 @@ pci_vfio_enable(void)
 {
        /* initialize group list */
        int i;
+       int module_vfio_type1;
 
        for (i = 0; i < VFIO_MAX_GROUPS; i++) {
                vfio_cfg.vfio_groups[i].fd = -1;
                vfio_cfg.vfio_groups[i].group_no = -1;
        }
+
+       module_vfio_type1 = rte_eal_check_module("vfio_iommu_type1");
+
+       /* return error directly */
+       if (module_vfio_type1 == -1) {
+               RTE_LOG(INFO, EAL, "Could not get loaded module details!\n");
+               return -1;
+       }
+
+       /* return 0 if VFIO modules not loaded */
+       if (module_vfio_type1 == 0) {
+               RTE_LOG(INFO, EAL, "VFIO modules not all loaded, "
+                       "skip VFIO support...\n");
+               return 0;
+       }
+
        vfio_cfg.vfio_container_fd = pci_vfio_get_container_fd();
 
        /* check if we have VFIO driver enabled */