From: Christoph Hellwig <hch@xxxxxx> And drop bits that are outdated or replaced by top-level Documentation. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- Documentation/libibverbs.md | 58 ++++++++++++++++ libibverbs/README | 164 -------------------------------------------- 2 files changed, 58 insertions(+), 164 deletions(-) create mode 100644 Documentation/libibverbs.md delete mode 100644 libibverbs/README diff --git a/Documentation/libibverbs.md b/Documentation/libibverbs.md new file mode 100644 index 000000000000..cbe076e0fcab --- /dev/null +++ b/Documentation/libibverbs.md @@ -0,0 +1,58 @@ +# Introduction + +libibverbs is a library that allows programs to use RDMA "verbs" for +direct access to RDMA (currently InfiniBand and iWARP) hardware from +userspace. For more information on RDMA verbs, see the InfiniBand +Architecture Specification vol. 1, especially chapter 11, and the RDMA +Consortium's RDMA Protocol Verbs Specification. + +# Using libibverbs + +### Device nodes + +The verbs library expects special character device files named +/dev/infiniband/uverbsN to be created. When you load the kernel +modules, including both the low-level driver for your IB hardware as +well as the ib_uverbs module, you should see one or more uverbsN +entries in /sys/class/infiniband_verbs in addition to the +/dev/infiniband/uverbsN character device files. + +To create the appropriate character device files automatically with +udev, a rule like + + KERNEL="uverbs*", NAME="infiniband/%k" + +can be used. This will create device nodes named + + /dev/infiniband/uverbs0 + +and so on. Since the RDMA userspace verbs should be safe for use by +non-privileged users, you may want to add an appropriate MODE or GROUP +to your udev rule. + +### Permissions + +To use IB verbs from userspace, a process must be able to access the +appropriate /dev/infiniband/uverbsN special device file. You can +check the permissions on this file with the command + + ls -l /dev/infiniband/uverbs* + +Make sure that the permissions on these files are such that the +user/group that your verbs program runs as can access the device file. + +To use IB verbs from userspace, a process must also have permission to +tell the kernel to lock sufficient memory for all of your registered +memory regions as well as the memory used internally by IB resources +such as queue pairs (QPs) and completion queues (CQs). To check your +resource limits, use the command + + ulimit -l + +(or "limit memorylocked" for csh-like shells). + +If you see a small number such as 32 (the units are KB) then you will +need to increase this limit. This is usually done for ordinary users +via the file /etc/security/limits.conf. More configuration may be +necessary if you are logging in via OpenSSH and your sshd is +configured to use privilege separation. diff --git a/libibverbs/README b/libibverbs/README deleted file mode 100644 index 848eb05917fb..000000000000 -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html