refactor: better used_ring method names

Update methods that set values in the `used_ring`
to be more descriptive and coherent.

Signed-off-by: Egor Lazarchuk <[email protected]>

Author: ShadowCurse

src/vmm/src/devices/virtio/queue.rs

@@ -452,7 +452,7 @@ impl Queue {
         // This fence ensures all descriptor writes are visible before the index update is.
         fence(Ordering::Release);
 
-        self.set_next_used(self.next_used.0, mem);
+        self.set_used_ring_idx(self.next_used.0, mem);
         Ok(())
     }
 
@@ -519,7 +519,7 @@ impl Queue {
     }
 
     /// Helper method that writes `val` to the `avail_event` field of the used ring.
-    fn set_avail_event<M: GuestMemory>(&mut self, val: u16, mem: &M) {
+    pub fn set_used_ring_avail_event<M: GuestMemory>(&mut self, val: u16, mem: &M) {
         debug_assert!(self.is_layout_valid(mem));
 
         // Used ring has layout:
@@ -540,7 +540,7 @@ impl Queue {
         mem.write_obj(val, avail_event_addr).unwrap();
     }
 
-    pub fn set_next_used<M: GuestMemory>(&mut self, val: u16, mem: &M) {
+    pub fn set_used_ring_idx<M: GuestMemory>(&mut self, val: u16, mem: &M) {
         debug_assert!(self.is_layout_valid(mem));
 
         // Used ring has layout:
@@ -552,8 +552,8 @@ impl Queue {
         // }
         // We calculate offset into `idx` field.
         let idx_offset = std::mem::size_of::<u16>();
-        let next_used_addr = self.used_ring.unchecked_add(usize_to_u64(idx_offset));
-        mem.write_obj(val, next_used_addr).unwrap();
+        let idx_addr = self.used_ring.unchecked_add(usize_to_u64(idx_offset));
+        mem.write_obj(val, idx_addr).unwrap();
     }
 
     /// Try to enable notification events from the guest driver. Returns true if notifications were
@@ -588,7 +588,7 @@ impl Queue {
         }
 
         // Set the next expected avail_idx as avail_event.
-        self.set_avail_event(self.next_avail.0, mem);
+        self.set_used_ring_avail_event(self.next_avail.0, mem);
 
         // Make sure all subsequent reads are performed after `set_avail_event`.
         fence(Ordering::SeqCst);
@@ -1482,10 +1482,10 @@ mod tests {
         let mut q = vq.create_queue();
         assert_eq!(vq.used.event.get(), 0);
 
-        q.set_avail_event(10, m);
+        q.set_used_ring_avail_event(10, m);
         assert_eq!(vq.used.event.get(), 10);
 
-        q.set_avail_event(u16::MAX, m);
+        q.set_used_ring_avail_event(u16::MAX, m);
         assert_eq!(vq.used.event.get(), u16::MAX);
     }