Use WHvResetPartition on Windows instead of manual vCPU state reset

.github/workflows/ValidatePullRequest.yml

@@ -89,7 +89,7 @@ jobs:
     # See: https://github.com/actions/runner/issues/2205
     if: ${{ !cancelled() && !failure() }}
     strategy:
-      fail-fast: true
+      fail-fast: false
       matrix:
         hypervisor: ['hyperv-ws2025', mshv3, kvm]
         cpu: [amd, intel]
@@ -112,7 +112,7 @@ jobs:
     # See: https://github.com/actions/runner/issues/2205
     if: ${{ !cancelled() && !failure() }}
     strategy:
-      fail-fast: true
+      fail-fast: false
       matrix:
         hypervisor: ['hyperv-ws2025', mshv3, kvm]
         cpu: [amd, intel]

.github/workflows/dep_build_test.yml

@@ -37,7 +37,7 @@ defaults:
 jobs:
   build-and-test:
     if: ${{ inputs.docs_only == 'false' }}
-    timeout-minutes: 45
+    timeout-minutes: 60
     runs-on: ${{ fromJson(
         format('["self-hosted", "{0}", "X64", "1ES.Pool=hld-{1}-{2}"]', 
           inputs.hypervisor == 'hyperv-ws2025' && 'Windows' || 'Linux', 

Justfile

@@ -235,7 +235,7 @@ test-integration target=default-target features="":
     {{ cargo-cmd }} test {{ if features =="" {"--features executable_heap"} else if features=="no-default-features" {"--no-default-features --features executable_heap"} else {"--no-default-features -F executable_heap," + features } }} --profile={{ if target == "debug" { "dev" } else { target } }} {{ target-triple-flag }} --test integration_test execute_on_heap
 
     @# run the rest of the integration tests
-    {{ cargo-cmd }} test -p hyperlight-host {{ if features =="" {''} else if features=="no-default-features" {"--no-default-features" } else {"--no-default-features -F " + features } }} --profile={{ if target == "debug" { "dev" } else { target } }} {{ target-triple-flag }} --test '*'
+    {{ cargo-cmd }} test -p hyperlight-host {{ if features =="" {''} else if features=="no-default-features" {"--no-default-features" } else {"--no-default-features -F " + features } }} --profile={{ if target == "debug" { "dev" } else { target } }} {{ target-triple-flag }} --test '*' -- --nocapture
 
 # tests compilation with no default features on different platforms
 test-compilation-no-default-features target=default-target:
@@ -323,6 +323,11 @@ clippy target=default-target: (witguest-wit)
 clippyw target=default-target: (witguest-wit)
     {{ cargo-cmd }} clippy --all-targets --all-features --target x86_64-pc-windows-gnu --profile={{ if target == "debug" { "dev" } else { target } }}  -- -D warnings
 
+# Cross-check for linux from a windows host using clippy (no linking needed).
+# Only checks lib targets to avoid dev-dependencies (criterion->alloca) that need a C cross-compiler.
+clippyl target=default-target:
+    {{ cargo-cmd }} clippy --lib --all-features --target x86_64-unknown-linux-gnu --profile={{ if target == "debug" { "dev" } else { target } }}  -- -D warnings
+
 clippy-guests target=default-target: (witguest-wit) (ensure-cargo-hyperlight)
     cd src/tests/rust_guests/simpleguest && cargo hyperlight clippy --profile={{ if target == "debug" { "dev" } else { target } }} -- -D warnings
     cd src/tests/rust_guests/witguest && cargo hyperlight clippy --profile={{ if target == "debug" { "dev" } else { target } }} -- -D warnings

src/hyperlight_guest_bin/src/arch/amd64/dispatch.rs

@@ -61,11 +61,8 @@ core::arch::global_asm!("
     .cfi_startproc
     .cfi_undefined rip
     jnz flush_done
-    mov rdi, cr4
-    xor rdi, 0x80
-    mov cr4, rdi
-    xor rdi, 0x80
-    mov cr4, rdi
+    mov rdi, cr3
+    mov cr3, rdi
     flush_done:
     call {internal_dispatch_function}\n
     mov dx, {halt_port}\n

src/hyperlight_guest_bin/src/guest_function/call.rs

@@ -86,6 +86,16 @@ pub(crate) fn internal_dispatch_function() {
     };
 
     let handle = unsafe { GUEST_HANDLE };
+    let canary = unsafe { crate::GUEST_HANDLE_CANARY };
+
+    if handle.peb().is_none() || canary != 0xDEAD_BEEF {
+        panic!(
+            "GUEST_HANDLE is None! canary={:#x} (expected 0xDEADBEEF), peb={:#x}. \
+             If canary is also 0, snapshot memory was not restored for this page.",
+            canary,
+            handle.peb().map_or(0, |p| p as u64),
+        );
+    }
 
     let function_call = handle
         .try_pop_shared_input_data_into::<FunctionCall>()

src/hyperlight_guest_bin/src/lib.rs

@@ -116,6 +116,10 @@ pub(crate) static HEAP_ALLOCATOR: ProfiledLockedHeap<32> =
     ProfiledLockedHeap(LockedHeap::<32>::empty());
 
 pub static mut GUEST_HANDLE: GuestHandle = GuestHandle::new();
+/// Canary value set to 0xDEAD_BEEF during init. If this reads as 0
+/// after snapshot restore while GUEST_HANDLE is None, the snapshot
+/// memory for this region was not properly restored.
+pub static mut GUEST_HANDLE_CANARY: u64 = 0;
 pub(crate) static mut REGISTERED_GUEST_FUNCTIONS: GuestFunctionRegister<GuestFunc> =
     GuestFunctionRegister::new();
 
@@ -205,6 +209,7 @@ pub(crate) extern "C" fn generic_init(
 ) -> u64 {
     unsafe {
         GUEST_HANDLE = GuestHandle::init(peb_address as *mut HyperlightPEB);
+        GUEST_HANDLE_CANARY = 0xDEAD_BEEF;
         #[allow(static_mut_refs)]
         let peb_ptr = GUEST_HANDLE.peb().unwrap();
 

src/hyperlight_host/src/hypervisor/hyperlight_vm/aarch64.rs

@@ -89,11 +89,15 @@ impl HyperlightVm {
         unimplemented!("get_snapshot_sregs")
     }
 
-    pub(crate) fn reset_vcpu(
+    pub(crate) fn reset_vm_state(&mut self) -> std::result::Result<(), RegisterError> {
+        unimplemented!("reset_vm_state")
+    }
+
+    pub(crate) fn restore_sregs(
         &mut self,
         _cr3: u64,
         _sregs: &CommonSpecialRegisters,
     ) -> std::result::Result<(), RegisterError> {
-        unimplemented!("reset_vcpu")
+        unimplemented!("restore_sregs")
     }
 }