feature(hypervisor-dmesg): runtime: add read_hypervisor_console wrapper

crates/runtime/src/lib.rs

@@ -297,4 +297,14 @@ impl Runtime {
         let context = RuntimeContext::new().await?;
         Ok(PowerManagementContext { context })
     }
+
+    pub async fn read_hypervisor_console(&self, clear: bool) -> Result<Arc<str>> {
+        let index = 0 as u32;
+        let (rawbuf, newindex) = self.context
+                                     .xen
+                                     .call
+                                     .read_console_ring_raw(clear, index).await?;
+        let buf = std::str::from_utf8(&rawbuf[..newindex as usize])?;
+        Ok(Arc::from(buf))
+    }
 }