From 3225c0c7c8bb1bb3abe7e5da21a6f1a25e13f07a Mon Sep 17 00:00:00 2001
From: Yi Wang <foxywang@tencent.com>
Date: Mon, 17 Jul 2023 20:42:10 +0800
Subject: [PATCH] vmm: Automatically pause VM for coredump

If the VMM is not already paused then pause the VM prior to executing
the coredump and then resume it after. If the VM is already paused then
the original state is maintained.

Signed-off-by: Yi Wang <foxywang@tencent.com>
---
 vmm/src/coredump.rs |  2 ++
 vmm/src/vm.rs       | 26 ++++++++++++++++++++------
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/vmm/src/coredump.rs b/vmm/src/coredump.rs
index 2e0cbf403..08c395286 100644
--- a/vmm/src/coredump.rs
+++ b/vmm/src/coredump.rs
@@ -36,6 +36,8 @@ pub struct DumpState {
 pub enum GuestDebuggableError {
     Coredump(anyhow::Error),
     CoredumpFile(std::io::Error),
+    Pause(vm_migration::MigratableError),
+    Resume(vm_migration::MigratableError),
 }
 
 pub trait GuestDebuggable: vm_migration::Pausable {
diff --git a/vmm/src/vm.rs b/vmm/src/vm.rs
index f28fcd668..078bdd8a4 100644
--- a/vmm/src/vm.rs
+++ b/vmm/src/vm.rs
@@ -2607,6 +2607,8 @@ impl GuestDebuggable for Vm {
     fn coredump(&mut self, destination_url: &str) -> std::result::Result<(), GuestDebuggableError> {
         event!("vm", "coredumping");
 
+        let mut resume = false;
+
         #[cfg(feature = "tdx")]
         {
             if let Some(ref platform) = self.config.lock().unwrap().platform {
@@ -2618,11 +2620,17 @@ impl GuestDebuggable for Vm {
             }
         }
 
-        let current_state = self.get_state().unwrap();
-        if current_state != VmState::Paused {
-            return Err(GuestDebuggableError::Coredump(anyhow!(
-                "Trying to coredump while VM is running"
-            )));
+        match self.get_state().unwrap() {
+            VmState::Running => {
+                self.pause().map_err(GuestDebuggableError::Pause)?;
+                resume = true;
+            }
+            VmState::Paused => {}
+            _ => {
+                return Err(GuestDebuggableError::Coredump(anyhow!(
+                    "Trying to coredump while VM is not running or paused"
+                )));
+            }
         }
 
         let coredump_state = self.get_dump_state(destination_url)?;
@@ -2643,7 +2651,13 @@ impl GuestDebuggable for Vm {
         self.memory_manager
             .lock()
             .unwrap()
-            .coredump_iterate_save_mem(&coredump_state)
+            .coredump_iterate_save_mem(&coredump_state)?;
+
+        if resume {
+            self.resume().map_err(GuestDebuggableError::Resume)?;
+        }
+
+        Ok(())
     }
 }