Update header size

kernel/run.py

@@ -57,7 +57,7 @@ def get_network_config(workers):
 NETWORK_CONFIG = get_network_config(MAX_WORKERS)
 NETWORK_INFRA_IP = '172.31.0.20/24'
 
-DCM_SCHEDULER_VERSION = "1.1.14"
+DCM_SCHEDULER_VERSION = "1.1.15"
 
 #
 # Important globals

kernel/src/arch/x86_64/rackscale/get_shmem_structure.rs

@@ -145,7 +145,7 @@ pub(crate) fn handle_get_shmem_structure(
 
             // Modify header and write into output buffer
             unsafe { encode(&logs, &mut payload) }.unwrap();
-            hdr.msg_len = core::mem::size_of::<[u64; MAX_PROCESSES]>() as u64;
+            hdr.msg_len = core::mem::size_of::<[u64; MAX_PROCESSES]>() as MsgLen;
         }
         ShmemStructure::NrLog => {
             let log_clone = Arc::into_raw(Arc::clone(&NR_LOG));
@@ -155,7 +155,7 @@ pub(crate) fn handle_get_shmem_structure(
 
             // Modify header and write into output buffer
             unsafe { encode(&[log_paddr], &mut payload) }.unwrap();
-            hdr.msg_len = core::mem::size_of::<[u64; 1]>() as u64;
+            hdr.msg_len = core::mem::size_of::<[u64; 1]>() as MsgLen;
         }
         ShmemStructure::WorkQueues => {
             let client_workqueue_clone = Arc::into_raw(Arc::clone(&RACKSCALE_CLIENT_WORKQUEUES));
@@ -168,7 +168,7 @@ pub(crate) fn handle_get_shmem_structure(
 
             // Modify header and write into output buffer
             unsafe { encode(&[arc_workqueue_paddr], &mut payload) }.unwrap();
-            hdr.msg_len = core::mem::size_of::<[u64; 1]>() as u64;
+            hdr.msg_len = core::mem::size_of::<[u64; 1]>() as MsgLen;
         }
     }
 

kernel/src/arch/x86_64/rackscale/kernelrpc.rs

@@ -88,7 +88,7 @@ impl TryFrom<RPCType> for KernelRpc {
     }
 }
 
-pub(crate) const KernelRpcRes_SIZE: u64 = core::mem::size_of::<KResult<(u64, u64)>>() as u64;
+pub(crate) const KernelRpcRes_SIZE: u16 = core::mem::size_of::<KResult<(u64, u64)>>() as MsgLen;
 
 #[inline(always)]
 pub(crate) fn construct_error_ret(hdr: &mut RPCHeader, payload: &mut [u8], err: KError) {
@@ -111,5 +111,5 @@ pub(crate) fn construct_ret_extra_data(
     unsafe { encode(&res, &mut payload) }.unwrap();
 
     // Modify header and write into output buffer
-    hdr.msg_len = KernelRpcRes_SIZE + additional_data_len;
+    hdr.msg_len = KernelRpcRes_SIZE + additional_data_len as MsgLen;
 }

lib/rpc/src/client.rs

@@ -34,13 +34,14 @@ impl Client {
     ) -> Result<(), RPCError> {
         // Calculate total data_out len
         let data_in_len = data_in.iter().fold(0, |acc, x| acc + x.len());
+        debug_assert!(data_in_len < MsgLen::MAX as usize);
 
         // Create request header and send message. It is safe to create a mutable reference here
         // because it is assumed there will only be one invocation of call() running at a time, and only
         // the client has access to this field.
         let mut hdr = &mut self.hdr;
         hdr.msg_type = rpc_id;
-        hdr.msg_len = data_in_len as u64;
+        hdr.msg_len = data_in_len as MsgLen;
         self.transport.send_msg(hdr, data_in)?;
 
         // Receive the response

lib/rpc/src/rpc.rs

@@ -23,17 +23,18 @@ pub enum RPCError {
 }
 unsafe_abomonate!(RPCError);
 
-// TODO(efficiency): type could probably be u8, but this seems easier for alignment w/ DCM?
-pub type RPCType = u64;
-pub const RPC_TYPE_CONNECT: u64 = 0u64;
+pub type RPCType = u8;
+pub const RPC_TYPE_CONNECT: u8 = 0u8;
+pub type MsgId = u8;
+pub type MsgLen = u16;
 
-#[derive(Debug, Default)]
-#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+#[repr(C, packed)]
 pub struct RPCHeader {
+    pub msg_id: MsgId,
     pub msg_type: RPCType,
-    pub msg_len: u64,
+    pub msg_len: MsgLen,
 }
-
 pub const HDR_LEN: usize = core::mem::size_of::<RPCHeader>();
 
 impl RPCHeader {