net/nfp: fix lock file usage

DPDK apps can be executed as non-root users but current NFP lock
file for avoiding concurrent accesses to CPP interface is precluding
this option or requires to modify system file permissions.

When the NFP device is bound to VFIO, this driver does not allow this
concurrent access, so the lock file is not required at all.

OVS-DPDK as executed in RedHat distributions is the main NFP user
needing this fix.

Fixes: c7e9729da6b5 ("net/nfp: support CPP")

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>

diff --git a/drivers/net/nfp/nfp_net.c b/drivers/net/nfp/nfp_net.c
index 34a8cad..faad1ee 100644 (file)
--- a/drivers/net/nfp/nfp_net.c
+++ b/drivers/net/nfp/nfp_net.c
@@ -3118,7 +3118,18 @@ static int nfp_pf_pci_probe(struct rte_pci_driver *pci_drv __rte_unused,
        if (!dev)
                return ret;
 
-       cpp = nfp_cpp_from_device_name(dev->device.name);
+       /*
+        * When device bound to UIO, the device could be used, by mistake,
+        * by two DPDK apps, and the UIO driver does not avoid it. This
+        * could lead to a serious problem when configuring the NFP CPP
+        * interface. Here we avoid this telling to the CPP init code to
+        * use a lock file if UIO is being used.
+        */
+       if (dev->kdrv == RTE_KDRV_VFIO)
+               cpp = nfp_cpp_from_device_name(dev->device.name, 0);
+       else
+               cpp = nfp_cpp_from_device_name(dev->device.name, 1);
+
        if (!cpp) {
                PMD_DRV_LOG(ERR, "A CPP handle can not be obtained");
                ret = -EIO;

diff --git a/drivers/net/nfp/nfpcore/nfp_cpp.h b/drivers/net/nfp/nfpcore/nfp_cpp.h
index 7e86214..de2ff84 100644 (file)
--- a/drivers/net/nfp/nfpcore/nfp_cpp.h
+++ b/drivers/net/nfp/nfpcore/nfp_cpp.h
@@ -31,6 +31,8 @@ struct nfp_cpp {
         * island XPB CSRs.
         */
        uint32_t imb_cat_table[16];
+
+       int driver_lock_needed;
 };
 
 /*
@@ -179,7 +181,8 @@ uint32_t __nfp_cpp_model_autodetect(struct nfp_cpp *cpp);
  *
  * @return NFP CPP handle, or NULL on failure (and set errno accordingly).
  */
-struct nfp_cpp *nfp_cpp_from_device_name(const char *devname);
+struct nfp_cpp *nfp_cpp_from_device_name(const char *devname,
+                                        int driver_lock_needed);
 
 /*
  * Free a NFP CPP handle

diff --git a/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c b/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
index 52b2948..2f5e7f6 100644 (file)
--- a/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
+++ b/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
@@ -850,9 +850,11 @@ nfp6000_init(struct nfp_cpp *cpp, const char *devname)
        memset(desc->busdev, 0, BUSDEV_SZ);
        strlcpy(desc->busdev, devname, sizeof(desc->busdev));
 
-       ret = nfp_acquire_process_lock(desc);
-       if (ret)
-               return -1;
+       if (cpp->driver_lock_needed) {
+               ret = nfp_acquire_process_lock(desc);
+               if (ret)
+                       return -1;
+       }
 
        snprintf(tmp_str, sizeof(tmp_str), "%s/%s/driver", PCI_DEVICES,
                 desc->busdev);
@@ -912,7 +914,8 @@ nfp6000_free(struct nfp_cpp *cpp)
                if (desc->bar[x - 1].iomem)
                        munmap(desc->bar[x - 1].iomem, 1 << (desc->barsz - 3));
        }
-       close(desc->lock);
+       if (cpp->driver_lock_needed)
+               close(desc->lock);
        close(desc->device);
        free(desc);
 }

diff --git a/drivers/net/nfp/nfpcore/nfp_cppcore.c b/drivers/net/nfp/nfpcore/nfp_cppcore.c
index 94d4a0b..f61143f 100644 (file)
--- a/drivers/net/nfp/nfpcore/nfp_cppcore.c
+++ b/drivers/net/nfp/nfpcore/nfp_cppcore.c
@@ -542,7 +542,7 @@ nfp_xpb_readl(struct nfp_cpp *cpp, uint32_t xpb_addr, uint32_t *value)
 }
 
 static struct nfp_cpp *
-nfp_cpp_alloc(const char *devname)
+nfp_cpp_alloc(const char *devname, int driver_lock_needed)
 {
        const struct nfp_cpp_operations *ops;
        struct nfp_cpp *cpp;
@@ -558,6 +558,7 @@ nfp_cpp_alloc(const char *devname)
                return NULL;
 
        cpp->op = ops;
+       cpp->driver_lock_needed = driver_lock_needed;
 
        if (cpp->op->init) {
                err = cpp->op->init(cpp, devname);
@@ -603,9 +604,9 @@ nfp_cpp_free(struct nfp_cpp *cpp)
 }
 
 struct nfp_cpp *
-nfp_cpp_from_device_name(const char *devname)
+nfp_cpp_from_device_name(const char *devname, int driver_lock_needed)
 {
-       return nfp_cpp_alloc(devname);
+       return nfp_cpp_alloc(devname, driver_lock_needed);
 }
 
 /*