chore: make Descriptor and set_avail_event public

These methods will be accessed by the next commit.

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

Author: ShadowCurse

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

@@ -38,12 +38,12 @@ pub enum QueueError {
 
 /// A virtio descriptor constraints with C representative.
 #[repr(C)]
-#[derive(Default, Clone, Copy)]
-struct Descriptor {
-    addr: u64,
-    len: u32,
-    flags: u16,
-    next: u16,
+#[derive(Debug, Default, Clone, Copy)]
+pub struct Descriptor {
+    pub addr: u64,
+    pub len: u32,
+    pub flags: u16,
+    pub next: u16,
 }
 
 // SAFETY: `Descriptor` is a POD and contains no padding.
@@ -482,7 +482,7 @@ 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_avail_event<M: GuestMemory>(&mut self, val: u16, mem: &M) {
         debug_assert!(self.is_layout_valid(mem));
 
         let avail_event_addr = self