hypervisor: emulator: emulate OR instruction

Signed-off-by: Wei Liu <liuwe@microsoft.com>

hypervisor/src/arch/x86/emulator/instructions/mod.rs

@@ -12,6 +12,7 @@ use iced_x86::*;
 pub mod cmp;
 pub mod mov;
 pub mod movs;
+pub mod or;
 
 fn get_op<T: CpuStateManager>(
     insn: &Instruction,

hypervisor/src/arch/x86/emulator/instructions/or.rs

@@ -0,0 +1,83 @@
+//
+// Copyright © 2021 Microsoft
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+#![allow(non_camel_case_types)]
+
+//
+// OR - Logical inclusive OR
+//
+
+use crate::arch::emulator::{EmulationError, PlatformEmulator};
+use crate::arch::x86::emulator::instructions::*;
+use crate::arch::x86::Exception;
+
+macro_rules! or_rm_r {
+    ($bound:ty) => {
+        fn emulate(
+            &self,
+            insn: &Instruction,
+            state: &mut T,
+            platform: &mut dyn PlatformEmulator<CpuState = T>,
+        ) -> Result<(), EmulationError<Exception>> {
+            let src_reg_value = get_op(&insn, 1, std::mem::size_of::<$bound>(), state, platform)
+                .map_err(EmulationError::PlatformEmulationError)?;
+
+            let dst_value = get_op(&insn, 0, std::mem::size_of::<$bound>(), state, platform)
+                .map_err(EmulationError::PlatformEmulationError)?;
+
+            let result = src_reg_value | dst_value;
+
+            set_op(
+                &insn,
+                0,
+                std::mem::size_of::<$bound>(),
+                state,
+                platform,
+                result,
+            )
+            .map_err(EmulationError::PlatformEmulationError)?;
+
+            Ok(())
+        }
+    };
+}
+
+pub struct Or_rm8_r8;
+impl<T: CpuStateManager> InstructionHandler<T> for Or_rm8_r8 {
+    or_rm_r!(u8);
+}
+
+#[cfg(test)]
+mod tests {
+    #![allow(unused_mut)]
+    use super::*;
+
+    use crate::arch::x86::emulator::mock_vmm::*;
+
+    #[test]
+    // or byte ptr [rax+1h], sil
+    fn test_or_rm8_r8() {
+        let rax = 0;
+        let insn = [0x40, 0x08, 0x70, 0x1];
+        let cpu_id = 0;
+        let ip: u64 = 0x1000;
+        let sil = 0xaa;
+        let memory = [0x0, 0x55];
+
+        let mut vmm = MockVmm::new(
+            ip,
+            vec![(Register::SIL, sil), (Register::RAX, rax)],
+            Some((0, &memory)),
+        );
+
+        assert!(vmm.emulate_first_insn(cpu_id, &insn).is_ok());
+
+        let mut out: [u8; 1] = [0; 1];
+
+        vmm.read_memory(rax + 1, &mut out).unwrap();
+        assert_eq!(u8::from_le_bytes(out), 0xff);
+    }
+}

hypervisor/src/arch/x86/emulator/mod.rs

@@ -524,7 +524,9 @@ impl<'a, T: CpuStateManager> Emulator<'a, T> {
             (mov, Movzx_r32_rm16),
             (mov, Movzx_r64_rm16),
             // MOVS
-            (movs, Movsd_m32_m32)
+            (movs, Movsd_m32_m32),
+            // OR
+            (or, Or_rm8_r8)
         );
 
         handler