From a993c9f05f780e3149feedeede83492d88856343 Mon Sep 17 00:00:00 2001
From: Wei-chung Hsu <weihsu@google.com>
Date: Fri, 28 Mar 2025 14:41:37 -0700
Subject: [PATCH] Added function get_enabled to export vring enable status.

The vring is disabled and RX/TX queue is set to
not-ready during snapshot. But vhost-device process
keeps access vring and queue after snapshot which
caused system hang. We need to export vring enabled
and disabled status for snapshot feature so that
the vhost-device would skip vring/queue access
aftr snapshot to avoid hang.

Signed-off-by: Wei-Chung Hsu <weihsu@google.com>
---
 vhost-user-backend/src/vring.rs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/vhost-user-backend/src/vring.rs b/vhost-user-backend/src/vring.rs
index 948f6878..dc4eeb8e 100644
--- a/vhost-user-backend/src/vring.rs
+++ b/vhost-user-backend/src/vring.rs
@@ -61,6 +61,9 @@ pub trait VringT<M: GuestAddressSpace>:
     /// Set vring enabled state.
     fn set_enabled(&self, enabled: bool);
 
+    /// Get vring enabled state.
+    fn get_enabled(&self) -> bool;
+
     /// Set queue addresses for descriptor table, available ring and used ring.
     fn set_queue_info(
         &self,
@@ -174,6 +177,10 @@ impl<M: GuestAddressSpace> VringState<M> {
         self.enabled = enabled;
     }
 
+    pub fn get_enabled(&self) -> bool {
+        self.enabled
+    }
+
     /// Set queue addresses for descriptor table, available ring and used ring.
     pub fn set_queue_info(
         &mut self,
@@ -327,6 +334,10 @@ impl<M: 'static + GuestAddressSpace> VringT<M> for VringMutex<M> {
         self.lock().set_enabled(enabled)
     }
 
+    fn get_enabled(&self) -> bool {
+        self.get_ref().enabled
+    }
+
     fn set_queue_info(
         &self,
         desc_table: u64,
@@ -442,6 +453,10 @@ impl<M: 'static + GuestAddressSpace> VringT<M> for VringRwLock<M> {
         self.write_lock().set_enabled(enabled)
     }
 
+    fn get_enabled(&self) -> bool {
+        self.get_ref().enabled
+    }
+
     fn set_queue_info(
         &self,
         desc_table: u64,