The generic NVMe library controller initialization process already handles enabling the controller; the RDMA transport should not need to set EN itself. For now, the discovery controller is cheating and not using the normal initialization process, so move the EN = 1 hack to the discovery controller bringup until it is overhauled to use the full nvme_ctrlr_process_init() path. The previous code where CC.EN was set to 1 before going through the controller init process would cause an EN = 1 to EN = 0 transition, which triggers a controller level reset. This change stops us from causing a reset during the controller startup sequence, which is defined by the NVMe over Fabrics spec as terminating the host/controller association (breaking the connection). Our NVMe over Fabrics target does not yet implement this correctly, but we should still do the right thing in preparation for a full reset implementation. This patch also reverts the NVMe over Fabrics target reset handling hack that was added as part of the NVMe over Fabrics host commit to its previous state of just printing an error message. Change-Id: I0aedd73dfd2dd1168e7b13b79575cc387737d4f0 Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Storage Performance Development Kit
The Storage Performance Development Kit (SPDK) provides a set of tools and libraries for writing high performance, scalable, user-mode storage applications. It achieves high performance by moving all of the necessary drivers into userspace and operating in a polled mode instead of relying on interrupts, which avoids kernel context switches and eliminates interrupt handling overhead.
The development kit currently includes:
Documentation
Doxygen API documentation is available, as well as a Porting Guide for porting SPDK to different frameworks and operating systems.
Many examples are available in the examples
directory.
Prerequisites
To build SPDK, some dependencies must be installed.
Fedora/CentOS:
sudo dnf install -y gcc gcc-c++ CUnit-devel libaio-devel openssl-devel
# Additional dependencies for NVMe over Fabrics:
sudo dnf install -y libibverbs-devel librdmacm-devel
Ubuntu/Debian:
sudo apt-get install -y gcc g++ make libcunit1-dev libaio-dev libssl-dev
# Additional dependencies for NVMe over Fabrics:
sudo apt-get install -y libibverbs-dev librdmacm-dev
FreeBSD:
- gcc
- gmake
- cunit
- openssl
Additionally, DPDK is required.
1) cd /path/to/spdk
2) wget http://fast.dpdk.org/rel/dpdk-16.11.tar.xz
3) tar xf dpdk-16.11.tar.xz
Linux:
4) (cd dpdk-16.11 && make install T=x86_64-native-linuxapp-gcc DESTDIR=.)
FreeBSD:
4) (cd dpdk-16.11 && gmake install T=x86_64-native-bsdapp-clang DESTDIR=.)
Building
Once the prerequisites are installed, run 'make' within the SPDK directory to build the SPDK libraries and examples.
make DPDK_DIR=/path/to/dpdk
If you followed the instructions above for building DPDK:
Linux:
make DPDK_DIR=./dpdk-16.11/x86_64-native-linuxapp-gcc
FreeBSD:
gmake DPDK_DIR=./dpdk-16.11/x86_64-native-bsdapp-clang
Hugepages and Device Binding
Before running an SPDK application, some hugepages must be allocated and any NVMe and I/OAT devices must be unbound from the native kernel drivers. SPDK includes a script to automate this process on both Linux and FreeBSD. This script should be run as root.
sudo scripts/setup.sh
Examples
Example code is located in the examples directory. The examples are compiled automatically as part of the build process. Simply call any of the examples with no arguments to see the help output. You'll likely need to run the examples as a privileged user (root) unless you've done additional configuration to grant your user permission to allocate huge pages and map devices through vfio.