From 041724a7cf970f6c95d1174e570e039e38823af4 Mon Sep 17 00:00:00 2001
From: Rob Bradford <robert.bradford@intel.com>
Date: Wed, 11 Nov 2020 18:32:03 +0000
Subject: [PATCH] hypervisor: Add ability to get dirty logged pages

Return a bitmap of pages that have been dirtied (written to) since it
was last called.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
---
 hypervisor/src/kvm/mod.rs | 8 ++++++++
 hypervisor/src/vm.rs      | 7 +++++++
 2 files changed, 15 insertions(+)

diff --git a/hypervisor/src/kvm/mod.rs b/hypervisor/src/kvm/mod.rs
index f94dff5e2..8d60da1d8 100644
--- a/hypervisor/src/kvm/mod.rs
+++ b/hypervisor/src/kvm/mod.rs
@@ -369,6 +369,14 @@ impl vm::Vm for KvmVm {
         self.vmmops.store(Some(Arc::new(vmmops)));
         Ok(())
     }
+    ///
+    /// Get dirty pages bitmap (one bit per page)
+    ///
+    fn get_dirty_log(&self, slot: u32, memory_size: u64) -> vm::Result<Vec<u64>> {
+        self.fd
+            .get_dirty_log(slot, memory_size as usize)
+            .map_err(|e| vm::HypervisorVmError::GetDirtyLog(e.into()))
+    }
 }
 /// Wrapper over KVM system ioctls.
 pub struct KvmHypervisor {
diff --git a/hypervisor/src/vm.rs b/hypervisor/src/vm.rs
index 072ee6edd..9184fbea9 100644
--- a/hypervisor/src/vm.rs
+++ b/hypervisor/src/vm.rs
@@ -147,6 +147,11 @@ pub enum HypervisorVmError {
     ///
     #[error("Failed to write to IO Bus: {0}")]
     IoBusWrite(#[source] anyhow::Error),
+    ///
+    /// Get dirty log error
+    ///
+    #[error("Failed to get dirty log: {0}")]
+    GetDirtyLog(#[source] anyhow::Error),
 }
 ///
 /// Result type for returning from a function
@@ -217,6 +222,8 @@ pub trait Vm: Send + Sync {
     fn set_state(&self, state: VmState) -> Result<()>;
     /// Set VmmOps interface
     fn set_vmmops(&self, vmmops: Box<dyn VmmOps>) -> Result<()>;
+    /// Get dirty pages bitmap
+    fn get_dirty_log(&self, slot: u32, memory_size: u64) -> Result<Vec<u64>>;
 }
 
 pub trait VmmOps: Send + Sync {