a sort of initial skeleton for cpuid.

Author: francis-starlab

mythril/src/emulate/cpuid.rs

@@ -1,10 +1,43 @@
 use crate::error::Result;
 use crate::{vcpu, vmexit};
 
+//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 CPUID_BRAND_STRING_1: u32 = 0x80000002;
+const CPUID_BRAND_STRING_2: u32 = 0x80000003;
+const CPUID_BRAND_STRING_3: 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.
+
+
+
 pub fn emulate_cpuid(
-    _vcpu: &mut vcpu::VCpu,
+    vcpu: &mut vcpu::VCpu,
     guest_cpu: &mut vmexit::GuestCpuState,
 ) -> Result<()> {
+    let eax = guest_cpu.rax as u32;
+
+    match eax {
+        CPUID_NAME => {
+            if vcpu.vm.read().config.override_cpu_name(){
+                todo!()
+            }
+        },
+        CPUID_MODEL_FAMILY_STEPPING => todo!(),
+        INTEL_CORE_CACHE_TOPOLOGY => {
+            _vcpu.vm.read().config.cpus()
+        }
+        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.")
+        }
+    }
+
     //FIXME: for now just use the actual cpuid
     let mut res = raw_cpuid::native_cpuid::cpuid_count(
         guest_cpu.rax as u32,

mythril/src/vm.rs

@@ -223,6 +223,7 @@ pub struct VirtualMachineConfig {
     virtual_devices: DeviceMap,
     physical_devices: PhysicalDeviceConfig,
     memory: u64, // in MB
+    override_cpu_name: bool
 }
 
 impl VirtualMachineConfig {
@@ -238,11 +239,12 @@ impl VirtualMachineConfig {
         physical_devices: PhysicalDeviceConfig,
     ) -> VirtualMachineConfig {
         VirtualMachineConfig {
-            cpus: cpus,
+            cpus,
             images: vec![],
             virtual_devices: DeviceMap::default(),
-            physical_devices: physical_devices,
-            memory: memory,
+            physical_devices,
+            memory,
+            override_cpu_name: false
         }
     }
 
@@ -280,6 +282,11 @@ impl VirtualMachineConfig {
     pub fn cpus(&self) -> &Vec<percore::CoreId> {
         &self.cpus
     }
+
+
+    pub fn override_cpu_name(&self) -> bool {
+        self.override_cpu_name
+    }
 }
 
 /// A virtual machine