runtime-rs: enable vm hugepage

support vm hugepage,set the hugetlbfs mount point as vm  memory path

Fixes:#5560
Signed-off-by: Zhongtao Hu <zhongtaohu.tim@linux.alibaba.com>

src/runtime-rs/config/configuration-dragonball.toml.in

@@ -136,6 +136,14 @@ block_device_driver = "@DEFBLOCKSTORAGEDRIVER_DB@"
 # of shim, does not need an external virtiofsd process.
 shared_fs = "@DBSHAREDFS@"
 
+# Enable huge pages for VM RAM, default false
+# Enabling this will result in the VM memory
+# being allocated using huge pages.
+# This is useful when you want to use vhost-user network
+# stacks within the container. This will automatically
+# result in memory pre allocation
+#enable_hugepages = true
+
 [agent.@PROJECT_TYPE@]
 container_pipe_size=@PIPESIZE@
 # If enabled, make the agent display debug-level messages.

src/runtime-rs/crates/hypervisor/src/dragonball/inner.rs

@@ -7,7 +7,7 @@
 use super::vmm_instance::VmmInstance;
 use crate::{
     device::Device, hypervisor_persist::HypervisorState, kernel_param::KernelParams, VmmState,
-    HYPERVISOR_DRAGONBALL, VM_ROOTFS_DRIVER_BLK,
+    DEV_HUGEPAGES, HUGETLBFS, HYPERVISOR_DRAGONBALL, SHMEM, VM_ROOTFS_DRIVER_BLK,
 };
 use anyhow::{anyhow, Context, Result};
 use async_trait::async_trait;
@@ -186,11 +186,18 @@ impl DragonballInner {
 
     fn set_vm_base_config(&mut self) -> Result<()> {
         let serial_path = [&self.run_dir, "console.sock"].join("/");
+        let (mem_type, mem_file_path) = if self.config.memory_info.enable_hugepages {
+            (String::from(HUGETLBFS), String::from(DEV_HUGEPAGES))
+        } else {
+            (String::from(SHMEM), String::from(""))
+        };
         let vm_config = VmConfigInfo {
             serial_path: Some(serial_path),
             mem_size_mib: self.config.memory_info.default_memory as usize,
             vcpu_count: self.config.cpu_info.default_vcpus as u8,
             max_vcpu_count: self.config.cpu_info.default_maxvcpus as u8,
+            mem_type,
+            mem_file_path,
             ..Default::default()
         };
         info!(sl!(), "vm config: {:?}", vm_config);

src/runtime-rs/crates/hypervisor/src/dragonball/vmm_instance.rs

@@ -327,9 +327,9 @@ impl VmmInstance {
                 }
             }
         }
-        return Err(anyhow::anyhow!(
+        Err(anyhow::anyhow!(
             "After {} attempts, it still doesn't work.",
             REQUEST_RETRY
-        ));
+        ))
     }
 }

src/runtime-rs/crates/hypervisor/src/lib.rs

@@ -26,6 +26,13 @@ use kata_types::config::hypervisor::Hypervisor as HypervisorConfig;
 // Config which driver to use as vm root dev
 const VM_ROOTFS_DRIVER_BLK: &str = "virtio-blk";
 const VM_ROOTFS_DRIVER_PMEM: &str = "virtio-pmem";
+// before using hugepages for VM, we need to mount hugetlbfs
+// /dev/hugepages will be the mount point
+// mkdir -p /dev/hugepages
+// mount -t hugetlbfs none /dev/hugepages
+const DEV_HUGEPAGES: &str = "/dev/hugepages";
+pub const HUGETLBFS: &str = "hugetlbfs";
+const SHMEM: &str = "shmem";
 
 pub const HYPERVISOR_DRAGONBALL: &str = "dragonball";
 #[derive(PartialEq)]

src/runtime-rs/crates/persist/src/lib.rs

@@ -26,7 +26,7 @@ pub fn to_disk<T: serde::Serialize>(value: &T, sid: &str) -> Result<()> {
         serde_json::to_writer_pretty(f, &j)?;
         return Ok(());
     }
-    return Err(anyhow!("invalid sid {}", sid));
+    Err(anyhow!("invalid sid {}", sid))
 }
 
 pub fn from_disk<T>(sid: &str) -> Result<T>
@@ -41,7 +41,7 @@ where
         let reader = BufReader::new(file);
         return serde_json::from_reader(reader).map_err(|e| anyhow!(e.to_string()));
     }
-    return Err(anyhow!("invalid sid {}", sid));
+    Err(anyhow!("invalid sid {}", sid))
 }
 
 #[cfg(test)]