feat: add RDMA listener to Mayastor Nvmf target

This adds the capability to listen for rdma connections to the Mayastor
Nvmf target if the rdma feature is enabled during installation. Any Nvmf
subsystem facing the host i.e. the nexus nvmf subsystem will now be able
to support tcp and rdma both.

Signed-off-by: Diwakar Sharma <diwakar.sharma@datacore.com>

Author: dsharma-dc

io-engine/src/bin/io-engine.rs

@@ -108,7 +108,7 @@ fn start_tokio_runtime(args: &MayastorCliArgs) {
 
     if args.rdma {
         env::set_var("ENABLE_RDMA", "true");
-        warn!("RDMA is enabled for Mayastor NVMEoF target");
+        warn!("RDMA is requested to be enabled for Mayastor NVMEoF target");
     }
 
     print_feature!("Async QPair connection", "spdk-async-qpair-connect");

io-engine/src/core/bdev.rs

@@ -210,6 +210,7 @@ where
     ) -> Result<Self::Output, Self::Error> {
         let me = unsafe { self.get_unchecked_mut() };
         let props = NvmfShareProps::from(props);
+        let is_lvol = me.driver() == "lvol";
 
         let ptpl = props.ptpl().as_ref().map(|ptpl| ptpl.path());
 
@@ -232,7 +233,7 @@ where
             .await
             .context(ShareNvmf {})?;
 
-        subsystem.start().await.context(ShareNvmf {})
+        subsystem.start(!is_lvol).await.context(ShareNvmf {})
     }
 
     fn create_ptpl(&self) -> Result<Option<PtplProps>, Self::Error> {

io-engine/src/core/env.rs

@@ -827,6 +827,11 @@ impl MayastorEnvironment {
             .map(|s| s.clone())
     }
 
+    /// Check if RDMA needs to be enabled for Mayastor target.
+    pub fn rdma(&self) -> bool {
+        self.rdma
+    }
+
     /// Detects IP address for NVMF target by the interface specified in CLI
     /// arguments.
     fn detect_nvmf_tgt_iface_ip(iface: &str) -> Result<String, String> {

io-engine/src/subsys/config/opts.rs

@@ -28,7 +28,7 @@ use spdk_rs::{
 
 use std::{
     convert::TryFrom,
-    fmt::{Debug, Display},
+    fmt::{Debug, Display, Formatter},
     mem::zeroed,
     ptr::null_mut,
     str::FromStr,
@@ -84,6 +84,26 @@ impl GetOpts for NexusOpts {
 /// Must be equal to the size of `spdk_nvmf_target_opts.crdt`.
 pub const TARGET_CRDT_LEN: usize = 3;
 
+#[derive(Clone, Default, Debug, PartialEq, Serialize, Deserialize)]
+pub enum NvmfTgtTransport {
+    Rdma,
+    #[default]
+    Tcp,
+}
+
+impl Display for NvmfTgtTransport {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                NvmfTgtTransport::Rdma => "rdma",
+                NvmfTgtTransport::Tcp => "tcp",
+            }
+        )
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(default, deny_unknown_fields)]
 pub struct NvmfTgtConfig {
@@ -94,11 +114,13 @@ pub struct NvmfTgtConfig {
     /// NVMF target Command Retry Delay in x100 ms.
     pub crdt: [u16; TARGET_CRDT_LEN],
     /// TCP transport options
-    pub opts: NvmfTcpTransportOpts,
+    pub opts_tcp: NvmfTcpTransportOpts,
     /// NVMF target interface (ip, mac, name or subnet).
     pub interface: Option<String>,
     /// Enable RDMA for NVMF target or not
     pub rdma: Option<bool>,
+    /// RDMA transport options
+    pub opts_rdma: NvmfRdmaTransportOpts,
 }
 
 impl From<NvmfTgtConfig> for Box<spdk_nvmf_target_opts> {
@@ -121,9 +143,10 @@ impl Default for NvmfTgtConfig {
             name: "mayastor_target".to_string(),
             max_namespaces: 2048,
             crdt: args.nvmf_tgt_crdt,
-            opts: NvmfTcpTransportOpts::default(),
+            opts_tcp: NvmfTcpTransportOpts::default(),
             interface: None,
             rdma: None,
+            opts_rdma: NvmfRdmaTransportOpts::default(),
         }
     }
 }
@@ -164,6 +187,36 @@ pub struct NvmfTcpTransportOpts {
     zcopy: bool,
 }
 
+/// Settings for the RDMA transport
+#[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
+#[serde(default, deny_unknown_fields)]
+pub struct NvmfRdmaTransportOpts {
+    /// max queue depth
+    max_queue_depth: u16,
+    /// max qpairs per controller
+    max_qpairs_per_ctrl: u16,
+    /// encapsulated data size
+    in_capsule_data_size: u32,
+    /// max IO size
+    max_io_size: u32,
+    /// IO unit size
+    io_unit_size: u32,
+    /// max admin queue depth per admin queue
+    max_aq_depth: u32,
+    /// num of shared buffers
+    num_shared_buf: u32,
+    /// cache size
+    buf_cache_size: u32,
+    /// dif
+    dif_insert_or_strip: bool,
+    /// abort execution timeout
+    abort_timeout_sec: u32,
+    /// acceptor poll rate, microseconds
+    acceptor_poll_rate: u32,
+    /// Use zero-copy operations if the underlying bdev supports them
+    zcopy: bool,
+}
+
 /// try to read an env variable or returns the default when not found
 fn try_from_env<T>(name: &str, default: T) -> T
 where
@@ -277,6 +330,29 @@ impl Default for NvmfTcpTransportOpts {
     }
 }
 
+// todo: Tune the defaults by experiments or recommendations, if required.
+impl Default for NvmfRdmaTransportOpts {
+    fn default() -> Self {
+        Self {
+            max_queue_depth: try_from_env("NVMF_RDMA_MAX_QUEUE_DEPTH", 128),
+            in_capsule_data_size: 8192,
+            max_io_size: 131_072,
+            io_unit_size: 8192,
+            max_qpairs_per_ctrl: try_from_env(
+                "NVMF_RDMA_MAX_QPAIRS_PER_CTRL",
+                32,
+            ),
+            num_shared_buf: try_from_env("NVMF_RDMA_NUM_SHARED_BUF", 2047),
+            buf_cache_size: try_from_env("NVMF_RDMA_BUF_CACHE_SIZE", 64),
+            dif_insert_or_strip: false,
+            max_aq_depth: 32,
+            abort_timeout_sec: 1,
+            acceptor_poll_rate: try_from_env("NVMF_ACCEPTOR_POLL_RATE", 10_000),
+            zcopy: try_from_env("NVMF_ZCOPY", 1) == 1,
+        }
+    }
+}
+
 /// we cannot add derives for YAML to these structs directly, so we need to
 /// copy them. The upside though, is that if the FFI structures change, we will
 /// know about it during compile time.
@@ -304,6 +380,30 @@ impl From<NvmfTcpTransportOpts> for spdk_nvmf_transport_opts {
     }
 }
 
+impl From<NvmfRdmaTransportOpts> for spdk_nvmf_transport_opts {
+    fn from(o: NvmfRdmaTransportOpts) -> Self {
+        Self {
+            max_queue_depth: o.max_queue_depth,
+            max_qpairs_per_ctrlr: o.max_qpairs_per_ctrl,
+            in_capsule_data_size: o.in_capsule_data_size,
+            max_io_size: o.max_io_size,
+            io_unit_size: o.io_unit_size,
+            max_aq_depth: o.max_aq_depth,
+            num_shared_buffers: o.num_shared_buf,
+            buf_cache_size: o.buf_cache_size,
+            dif_insert_or_strip: o.dif_insert_or_strip,
+            reserved29: Default::default(),
+            abort_timeout_sec: o.abort_timeout_sec,
+            association_timeout: 120000,
+            transport_specific: std::ptr::null(),
+            opts_size: std::mem::size_of::<spdk_nvmf_transport_opts>() as u64,
+            acceptor_poll_rate: o.acceptor_poll_rate,
+            zcopy: o.zcopy,
+            reserved61: Default::default(),
+        }
+    }
+}
+
 /// generic settings for the NVMe bdev (all our replicas)
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
 #[serde(default, deny_unknown_fields)]

io-engine/src/subsys/nvmf/subsystem.rs

@@ -68,6 +68,7 @@ use crate::{
     ffihelper::{cb_arg, done_cb, AsStr, FfiResult, IntoCString},
     lvs::Lvol,
     subsys::{
+        config::opts::NvmfTgtTransport,
         make_subsystem_serial,
         nvmf::{transport::TransportId, Error, NVMF_TGT},
         Config,
@@ -799,7 +800,7 @@ impl NvmfSubsystem {
     }
 
     // we currently allow all listeners to the subsystem
-    async fn add_listener(&self) -> Result<(), Error> {
+    async fn add_listener(&self, xprt: NvmfTgtTransport) -> Result<(), Error> {
         extern "C" fn listen_cb(arg: *mut c_void, status: i32) {
             let s = unsafe { Box::from_raw(arg as *mut oneshot::Sender<i32>) };
             s.send(status).unwrap();
@@ -808,8 +809,11 @@ impl NvmfSubsystem {
         let cfg = Config::get();
 
         // dont yet enable both ports, IOW just add one transportID now
-
-        let trid_replica = TransportId::new(cfg.nexus_opts.nvmf_replica_port);
+        let trid_replica = if xprt == NvmfTgtTransport::Tcp {
+            TransportId::new(cfg.nexus_opts.nvmf_replica_port)
+        } else {
+            TransportId::new_with_rdma(cfg.nexus_opts.nvmf_replica_port)
+        };
 
         let (s, r) = oneshot::channel::<i32>();
         unsafe {
@@ -908,8 +912,21 @@ impl NvmfSubsystem {
     /// start the subsystem previously created -- note that we destroy it on
     /// failure to ensure the state is not in limbo and to avoid leaking
     /// resources
-    pub async fn start(self) -> Result<String, Error> {
-        self.add_listener().await?;
+    pub async fn start(self, need_rdma: bool) -> Result<String, Error> {
+        self.add_listener(NvmfTgtTransport::Tcp).await?;
+        if need_rdma {
+            let _ =
+                self.add_listener(NvmfTgtTransport::Rdma)
+                    .await
+                    .map_err(|e| {
+                        warn!(
+                            "NvmfSubsystem RDMA listener add failed {}. \
+                        Subsystem will be accessible over TCP only.\
+                        {:?}",
+                            e, self
+                        );
+                    });
+        }
 
         if let Err(e) = self
             .change_state("start", |ss, cb, arg| unsafe {
@@ -1119,7 +1136,10 @@ impl NvmfSubsystem {
     pub fn uri_endpoints(&self) -> Option<Vec<String>> {
         if let Some(v) = self.listeners_to_vec() {
             let nqn = self.get_nqn();
-            Some(v.iter().map(|t| format!("{t}/{nqn}")).collect::<Vec<_>>())
+            let retvec = Some(
+                v.iter().map(|t| format!("{t}/{nqn}")).collect::<Vec<_>>(),
+            );
+            retvec
         } else {
             None
         }