Fix

Signed-off-by: Ludvig Liljenberg <[email protected]>

Author: ludfjig

.github/workflows/dep_rust.yml

@@ -133,7 +133,7 @@ jobs:
           just test-rust ${{ matrix.config }} inprocess,seccomp,${{ matrix.hypervisor == 'mshv' && 'mshv' || 'kvm' }} 
 
           # make sure certain cargo features compile
-          cargo check -p hyperlight-host --features dump_on_crash
+          cargo check -p hyperlight-host --features crashdump
 
           # without any driver (shouldn't compile)
           just test-rust-feature-compilation-fail ${{ matrix.config }}

docs/debugging-hyperlight.md

@@ -39,6 +39,6 @@ cargo test --package hyperlight-host --test integration_test --features print_de
 
 ## Dumping the memory configuration, virtual processor register state and memory contents on a crash or unexpected VM Exit
 
-To dump the details of the memory configuration, the virtual processors register state and the contents of the VM memory set the feature `dump_on_crash` and run a debug build. This will result in a dump file being created in the temporary directory. The name and location of the dump file will be printed to the console and logged as an error message.
+To dump the details of the memory configuration, the virtual processors register state and the contents of the VM memory set the feature `crashdump` and run a debug build. This will result in a dump file being created in the temporary directory. The name and location of the dump file will be printed to the console and logged as an error message.
 
 There are no tools at this time to analyze the dump file, but it can be useful for debugging.

src/hyperlight_host/Cargo.toml

@@ -118,9 +118,7 @@ function_call_metrics = []
 executable_heap = []
 # This feature enables printing of debug information to stdout in debug builds
 print_debug = []
-# This feature enables dunping of the VMs details to a file when an unexpected or error exit occurs in a VM in debug mode
-# the name of the file is output to stdout and logged.
-crashdump = ["dep:tempfile"]
+crashdump = ["dep:tempfile"] # Dumps the VM state to a file on unexpected errors or crashes. The path of the file will be printed on stdout and logged. This feature can only be used in debug builds.
 kvm = ["dep:kvm-bindings", "dep:kvm-ioctls"]
 mshv = ["dep:mshv-bindings", "dep:mshv-ioctls"]
 inprocess = []

src/hyperlight_host/src/hypervisor/hyperv_windows.rs

@@ -508,18 +508,6 @@ impl Hypervisor for HypervWindowsDriver {
                     "HyperV Memory Access Details :\n GPA: {:#?}\n Access Info :{:#?}\n {:#?} ",
                     gpa, access_info, &self
                 );
-                #[cfg(all(debug_assertions, feature = "dump_on_crash"))]
-                {
-                    if let Err(e) = unsafe {
-                        self.write_dump_file(
-                            self.mem_regions.clone(),
-                            self.source_address.add(PAGE_SIZE_USIZE) as *const u8,
-                            self.size,
-                        )
-                    } {
-                        println!("Error dumping memory: {}", e);
-                    }
-                }
 
                 match self.get_memory_access_violation(gpa as usize, &self.mem_regions, access_info)
                 {
@@ -539,18 +527,6 @@ impl Hypervisor for HypervWindowsDriver {
                     "HyperV Unexpected Exit Details :#nReason {:#?}\n {:#?}",
                     exit_context.ExitReason, &self
                 );
-                #[cfg(all(debug_assertions, feature = "dump_on_crash"))]
-                {
-                    if let Err(e) = unsafe {
-                        self.write_dump_file(
-                            self.mem_regions.clone(),
-                            self.source_address.add(PAGE_SIZE_USIZE) as *const u8,
-                            self.size,
-                        )
-                    } {
-                        println!("Error dumping memory: {}", e);
-                    }
-                }
                 match self.get_exit_details(exit_context.ExitReason) {
                     Ok(error) => HyperlightExit::Unknown(error),
                     Err(e) => HyperlightExit::Unknown(format!("Error getting exit details: {}", e)),

src/hyperlight_host/src/hypervisor/mod.rs

@@ -204,14 +204,14 @@ impl VirtualCPU {
         mem_access_fn: Arc<Mutex<dyn MemAccessHandlerCaller>>,
     ) -> Result<()> {
         loop {
-            match hv.run()? {
-                HyperlightExit::Halt() => {
+            match hv.run() {
+                Ok(HyperlightExit::Halt()) => {
                     break;
                 }
-                HyperlightExit::IoOut(port, data, rip, instruction_length) => {
+                Ok(HyperlightExit::IoOut(port, data, rip, instruction_length)) => {
                     hv.handle_io(port, data, rip, instruction_length, outb_handle_fn.clone())?
                 }
-                HyperlightExit::Mmio(addr) => {
+                Ok(HyperlightExit::Mmio(addr)) => {
                     #[cfg(crashdump)]
                     crashdump::crashdump_to_tempfile(hv)?;
 
@@ -223,7 +223,10 @@ impl VirtualCPU {
 
                     log_then_return!("MMIO access address {:#x}", addr);
                 }
-                HyperlightExit::AccessViolation(addr, tried, region_permission) => {
+                Ok(HyperlightExit::AccessViolation(addr, tried, region_permission)) => {
+                    #[cfg(crashdump)]
+                    crashdump::crashdump_to_tempfile(hv)?;
+
                     if region_permission.intersects(MemoryRegionFlags::STACK_GUARD) {
                         return Err(HyperlightError::StackOverflow());
                     }
@@ -233,7 +236,7 @@ impl VirtualCPU {
                         region_permission
                     ));
                 }
-                HyperlightExit::Cancelled() => {
+                Ok(HyperlightExit::Cancelled()) => {
                     // Shutdown is returned when the host has cancelled execution
                     // After termination, the main thread will re-initialize the VM
                     if let Some(hvh) = hv_handler {
@@ -246,10 +249,19 @@ impl VirtualCPU {
                     int_counter_inc!(&NumberOfCancelledGuestExecutions);
                     log_then_return!(ExecutionCanceledByHost());
                 }
-                HyperlightExit::Unknown(reason) => {
+                Ok(HyperlightExit::Unknown(reason)) => {
+                    #[cfg(crashdump)]
+                    crashdump::crashdump_to_tempfile(hv)?;
+
                     log_then_return!("Unexpected VM Exit {:?}", reason);
                 }
-                HyperlightExit::Retry() => continue,
+                Ok(HyperlightExit::Retry()) => continue,
+                Err(e) => {
+                    #[cfg(crashdump)]
+                    crashdump::crashdump_to_tempfile(hv)?;
+
+                    return Err(e);
+                }
             }
         }