Change u64 to usize in un/register_event

We can safely use usize instead of u64, because normally we will
not register a data that exceeds the size of usize

Signed-off-by: Wenyu Huang <[email protected]>

Author: uran0sH

vhost-user-backend/src/event_loop.rs

@@ -116,9 +116,9 @@ where
     ///
     /// When this event is later triggered, the backend implementation of `handle_event` will be
     /// called.
-    pub fn register_listener(&self, fd: RawFd, ev_type: EventSet, data: u64) -> Result<()> {
+    pub fn register_listener(&self, fd: RawFd, ev_type: EventSet, data: usize) -> Result<()> {
         // `data` range [0...num_queues] is reserved for queues and exit event.
-        if data <= self.backend.num_queues() as u64 {
+        if data <= self.backend.num_queues() {
             Err(io::Error::from_raw_os_error(libc::EINVAL))
         } else {
             self.register_event(fd, ev_type, data)
@@ -129,23 +129,29 @@ where
     ///
     /// If the event is triggered after this function has been called, the event will be silently
     /// dropped.
-    pub fn unregister_listener(&self, fd: RawFd, ev_type: EventSet, data: u64) -> Result<()> {
+    pub fn unregister_listener(&self, fd: RawFd, ev_type: EventSet, data: usize) -> Result<()> {
         // `data` range [0...num_queues] is reserved for queues and exit event.
-        if data <= self.backend.num_queues() as u64 {
+        if data <= self.backend.num_queues() {
             Err(io::Error::from_raw_os_error(libc::EINVAL))
         } else {
             self.unregister_event(fd, ev_type, data)
         }
     }
 
-    pub(crate) fn register_event(&self, fd: RawFd, ev_type: EventSet, data: u64) -> Result<()> {
-        self.epoll
-            .ctl(ControlOperation::Add, fd, EpollEvent::new(ev_type, data))
+    pub(crate) fn register_event(&self, fd: RawFd, ev_type: EventSet, data: usize) -> Result<()> {
+        self.epoll.ctl(
+            ControlOperation::Add,
+            fd,
+            EpollEvent::new(ev_type, data as u64),
+        )
     }
 
-    pub(crate) fn unregister_event(&self, fd: RawFd, ev_type: EventSet, data: u64) -> Result<()> {
-        self.epoll
-            .ctl(ControlOperation::Delete, fd, EpollEvent::new(ev_type, data))
+    pub(crate) fn unregister_event(&self, fd: RawFd, ev_type: EventSet, data: usize) -> Result<()> {
+        self.epoll.ctl(
+            ControlOperation::Delete,
+            fd,
+            EpollEvent::new(ev_type, data as u64),
+        )
     }
 
     /// Run the event poll loop to handle all pending events on registered fds.

vhost-user-backend/src/handler.rs

@@ -212,7 +212,7 @@ where
                 if shifted_queues_mask & 1u64 == 1u64 {
                     let evt_idx = queues_mask.count_ones() - shifted_queues_mask.count_ones();
                     self.handlers[thread_index]
-                        .register_event(fd.as_raw_fd(), EventSet::IN, u64::from(evt_idx))
+                        .register_event(fd.as_raw_fd(), EventSet::IN, evt_idx as usize)
                         .map_err(VhostUserError::ReqHandlerError)?;
                     break;
                 }
@@ -436,7 +436,7 @@ where
                 if shifted_queues_mask & 1u64 == 1u64 {
                     let evt_idx = queues_mask.count_ones() - shifted_queues_mask.count_ones();
                     self.handlers[thread_index]
-                        .unregister_event(fd.as_raw_fd(), EventSet::IN, u64::from(evt_idx))
+                        .unregister_event(fd.as_raw_fd(), EventSet::IN, evt_idx as usize)
                         .map_err(VhostUserError::ReqHandlerError)?;
                     break;
                 }