Fix ownership Sync issues

Signed-off-by: Simon Davies <[email protected]>

Author: simongdavies

src/hyperlight_host/src/hypervisor/hyperv_linux.rs

@@ -78,13 +78,14 @@ use crate::HyperlightError;
 use crate::mem::memory_region::{MemoryRegion, MemoryRegionFlags};
 use crate::mem::ptr::{GuestPtr, RawPtr};
 use crate::mem::shared_mem::HostSharedMemory;
+use crate::sandbox::SandboxConfiguration;
 #[cfg(feature = "trace_guest")]
 use crate::sandbox::TraceInfo;
 use crate::sandbox::host_funcs::FunctionRegistry;
+use crate::sandbox::mem_mgr::MemMgrWrapper;
 use crate::sandbox::outb::handle_outb;
 #[cfg(crashdump)]
 use crate::sandbox::uninitialized::SandboxRuntimeConfig;
-use crate::sandbox::{MemMgrWrapper, SandboxConfiguration};
 use crate::{Result, log_then_return, new_error};
 
 #[cfg(gdb)]

src/hyperlight_host/src/hypervisor/hyperv_windows.rs

@@ -295,13 +295,12 @@ pub(crate) struct HypervWindowsDriver {
     #[allow(dead_code)]
     trace_info: TraceInfo,
 }
-/* This does not automatically impl Send/Sync because the host
+/* This does not automatically impl Send because the host
  * address of the shared memory region is a raw pointer, which are
- * marked as !Send and !Sync. However, the access patterns used
+ * marked as !Send (and !Sync). However, the access patterns used
  * here are safe.
  */
 unsafe impl Send for HypervWindowsDriver {}
-unsafe impl Sync for HypervWindowsDriver {}
 
 impl HypervWindowsDriver {
     #[allow(clippy::too_many_arguments)]

src/hyperlight_host/src/hypervisor/kvm.rs

@@ -16,10 +16,8 @@ limitations under the License.
 
 use std::convert::TryFrom;
 use std::fmt::Debug;
-use std::sync::Arc;
-#[cfg(gdb)]
-use std::sync::Mutex;
 use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
+use std::sync::{Arc, Mutex};
 
 use kvm_bindings::{kvm_fpu, kvm_regs, kvm_userspace_memory_region};
 use kvm_ioctls::Cap::UserMemory;
@@ -609,24 +607,41 @@ impl Hypervisor for KVMDriver {
             padded[..copy_len].copy_from_slice(&data[..copy_len]);
             let value = u32::from_le_bytes(padded);
 
-            let mem_mgr = self
-                .mem_mgr
-                .as_mut()
-                .ok_or_else(|| new_error!("mem_mgr not initialized"))?;
-            let host_funcs = self
-                .host_funcs
-                .as_ref()
-                .ok_or_else(|| new_error!("host_funcs not initialized"))?
-                .clone();
-
-            handle_outb(
-                mem_mgr,
-                host_funcs,
-                #[cfg(feature = "trace_guest")]
-                self,
-                port,
-                value,
-            )?;
+            #[cfg(feature = "trace_guest")]
+            {
+                // We need to handle the borrow checker issue where we need both:
+                // - &mut MemMgrWrapper (from self.mem_mgr.as_mut())
+                // - &mut dyn Hypervisor (from self)
+                // We'll use a temporary approach to extract the mem_mgr temporarily
+                let mem_mgr_option = self.mem_mgr.take();
+                let mut mem_mgr =
+                    mem_mgr_option.ok_or_else(|| new_error!("mem_mgr not initialized"))?;
+                let host_funcs = self
+                    .host_funcs
+                    .as_ref()
+                    .ok_or_else(|| new_error!("host_funcs not initialized"))?
+                    .clone();
+
+                handle_outb(&mut mem_mgr, host_funcs, self, port, value)?;
+
+                // Put the mem_mgr back
+                self.mem_mgr = Some(mem_mgr);
+            }
+
+            #[cfg(not(feature = "trace_guest"))]
+            {
+                let mem_mgr = self
+                    .mem_mgr
+                    .as_mut()
+                    .ok_or_else(|| new_error!("mem_mgr not initialized"))?;
+                let host_funcs = self
+                    .host_funcs
+                    .as_ref()
+                    .ok_or_else(|| new_error!("host_funcs not initialized"))?
+                    .clone();
+
+                handle_outb(mem_mgr, host_funcs, port, value)?;
+            }
         }
 
         Ok(())

src/hyperlight_host/src/hypervisor/mod.rs

@@ -136,7 +136,7 @@ pub enum TraceRegister {
 }
 
 /// A common set of hypervisor functionality
-pub(crate) trait Hypervisor: Debug + Sync + Send {
+pub(crate) trait Hypervisor: Debug + Send {
     /// Initialise the internally stored vCPU with the given PEB address and
     /// random number seed, then run it until a HLT instruction.
     #[allow(clippy::too_many_arguments)]