got some basic cpuid stuff working.

Author: francis-starlab

mythril/Cargo.lock

@@ -28,6 +28,7 @@ serde_json = {version = "^1", default-features = false, features = ["alloc"] }
 spin = "0.5"
 ux = { version = "0.1.3", default-features = false }
 managed = { version = "0.8.0", features = ["map", "alloc"], default-features = false }
+bitfield = "0.13.2"
 
 [dependencies.iced-x86]
 version = "1.8.0"

mythril/Cargo.toml

@@ -1,42 +1,88 @@
 use crate::error::Result;
 use crate::{vcpu, vmexit};
+use raw_cpuid::CpuIdResult;
+use arrayvec::ArrayVec;
+use core::convert::TryInto;
+use bitfield::bitfield;
 
 //Used https://c9x.me/x86/html/file_module_x86_id_45.html as guid for implementing this.
 const CPUID_NAME: u32 = 0;
 const CPUID_MODEL_FAMILY_STEPPING: u32 = 1;
 const CPUID_CACHE_TLB_INFO: u32 = 2;
-const INTEL_CORE_CACHE_TOPOLOGY : u32 = 4;
+const INTEL_CORE_CACHE_TOPOLOGY: u32 = 4;
 const CPUID_BRAND_STRING_1: u32 = 0x80000002;
 const CPUID_BRAND_STRING_2: u32 = 0x80000003;
 const CPUID_BRAND_STRING_3: u32 = 0x80000004;
+const MAX_CPUID_INPUT: u32 = 0x80000004;
 //todo //CPUID leaves above 2 and below 80000000H are visible only when
 //     // IA32_MISC_ENABLE[bit 22] has its default value of 0.
 
 
+//
+// bitfield! {
+//     pub struct IntelCoreCacheTopologyEaxRes(u32)
+//     impl Debug;
+//     impl Copy;
+//
+// }
 
-pub fn emulate_cpuid(
-    vcpu: &mut vcpu::VCpu,
-    guest_cpu: &mut vmexit::GuestCpuState,
-) -> Result<()> {
-    let eax = guest_cpu.rax as u32;
+bitfield! {
+    pub struct IntelTypeFamilyModelSteppingIDEaxRes(u32);
+    impl Debug;
+    stepping_id, _: 3,0;
+    model,_:7,4;
+    family_id,_:11,8;
+    processor_type,_:13,12;
+    extended_model_id,_:19,16;
+    extended_family_id,_:27,20;
+}
+
+fn get_cpu_id_result(vcpu: &vcpu::VCpu, eax: u32, ecx: u32) -> Option<CpuIdResult> {
+    const NAME_CREATION_ERROR_MESSAGE: &'static str = "Somehow bytes was not actually a 12 element array";
 
     match eax {
         CPUID_NAME => {
-            if vcpu.vm.read().config.override_cpu_name(){
-                todo!()
+            if vcpu.vm.read().config.override_cpu_name() {
+                let cpu_name = "MythrilCPU__";
+                let bytes = cpu_name.chars().map(|char| char as u8).collect::<ArrayVec<[u8; 12]>>();
+                let first_bytes: [u8; 4] = bytes[0..4].try_into().expect(NAME_CREATION_ERROR_MESSAGE);
+                let second_bytes: [u8; 4] = bytes[4..8].try_into().expect(NAME_CREATION_ERROR_MESSAGE);
+                let third_bytes: [u8; 4] = bytes[8..12].try_into().expect(NAME_CREATION_ERROR_MESSAGE);
+                return Some(CpuIdResult {
+                    eax: MAX_CPUID_INPUT,
+                    ebx: u32::from_le_bytes(first_bytes),
+                    ecx: u32::from_le_bytes(second_bytes),
+                    edx: u32::from_le_bytes(third_bytes),
+                });
             }
-        },
-        CPUID_MODEL_FAMILY_STEPPING => todo!(),
+        }
+        CPUID_MODEL_FAMILY_STEPPING => {
+
+        }
         INTEL_CORE_CACHE_TOPOLOGY => {
-            _vcpu.vm.read().config.cpus()
+            let core_cpus = vcpu.vm.read().config.cpus();
+
+            todo!()
+        }
+        CPUID_BRAND_STRING_1..=CPUID_BRAND_STRING_2 => {
+            if vcpu.vm.read().config.override_cpu_name() { todo!("CPU Brand string not implemented yet") }
+            return None;
         }
-        CPUID_BRAND_STRING_1 => todo!(),
-        CPUID_BRAND_STRING_2 => todo!(),
         _ => {
-            // dbg!(eax);
-            // todo!("If you are reading this then a invalid arg was passed to cpuid. In principle we should prob fault here or something, but this probably indicates a bug.")
+            //TODO for code review. Idk how I feel about silently fallingback on real cpuid here.
+            // I would perhaps prefer to put a todo!() and explicitly implement stuff.
+            return None;
         }
-    }
+    };
+    panic!()
+}
+
+pub fn emulate_cpuid(
+    vcpu: &mut vcpu::VCpu,
+    guest_cpu: &mut vmexit::GuestCpuState,
+) -> Result<()> {
+    let eax = guest_cpu.rax as u32;
+
 
     //FIXME: for now just use the actual cpuid
     let mut res = raw_cpuid::native_cpuid::cpuid_count(