Replace winnt_fix by cpuid_level, make configurable

src/browser/main.js

@@ -1030,6 +1030,7 @@
             settings.cmdline = infos.cmdline;
             settings.bzimage_initrd_from_filesystem = infos.bzimage_initrd_from_filesystem;
             settings.mac_address_translation = infos.mac_address_translation;
+            settings.cpuid_level = infos.cpuid_level;
 
             settings.acpi = (!infos.state && settings.acpi !== undefined) ? settings.acpi : infos.acpi;
             settings.memory_size = (!infos.state && settings.memory_size) ? settings.memory_size : infos.memory_size;
@@ -1290,6 +1291,7 @@
             "filesystem": settings.filesystem || {},
             "disable_speaker": disable_audio,
             "mac_address_translation": settings.mac_address_translation,
+            "cpuid_level": settings.cpuid_level,
 
             "autostart": true,
         });

src/browser/starter.js

@@ -266,6 +266,7 @@ V86Starter.prototype.continue_init = async function(emulator, options)
     settings.cmdline = options["cmdline"];
     settings.preserve_mac_from_state_image = options["preserve_mac_from_state_image"];
     settings.mac_address_translation = options["mac_address_translation"];
+    settings.cpuid_level = options["cpuid_level"];
 
     if(options["network_adapter"])
     {

src/cpu.js

@@ -263,6 +263,8 @@ CPU.prototype.wasm_patch = function()
     this.set_tsc = get_import("set_tsc");
     this.store_current_tsc = get_import("store_current_tsc");
 
+    this.set_cpuid_level = get_import("set_cpuid_level");
+
     if(DEBUG)
     {
         this.jit_force_generate_unsafe = get_optional_import("jit_force_generate_unsafe");
@@ -657,6 +659,8 @@ CPU.prototype.init = function(settings, device_bus)
     this.create_memory(typeof settings.memory_size === "number" ?
         settings.memory_size : 1024 * 1024 * 64);
 
+    settings.cpuid_level && this.set_cpuid_level(settings.cpuid_level);
+
     this.acpi_enabled[0] = +settings.acpi;
 
     this.reset_cpu();

src/rust/cpu/cpu.rs

@@ -264,6 +264,8 @@ pub const DEBUG: bool = cfg!(debug_assertions);
 pub const LOOP_COUNTER: i32 = 100_003;
 pub const TSC_RATE: f64 = 1_000_000.0;
 
+pub static mut cpuid_level: u32 = 0x16;
+
 pub static mut jit_block_boundary: bool = false;
 
 pub static mut rdtsc_imprecision_offset: u64 = 0;
@@ -4188,3 +4190,6 @@ pub unsafe fn reset_cpu() {
 
     jit::jit_clear_cache(jit::get_jit_state());
 }
+
+#[no_mangle]
+pub unsafe fn set_cpuid_level(level: u32) { cpuid_level = level }

src/rust/cpu/instructions_0f.rs

@@ -3143,18 +3143,12 @@ pub unsafe fn instr_0FA2() {
     let mut edx = 0;
     let mut ebx = 0;
 
-    let winnt_fix = false;
     let level = read_reg32(EAX) as u32;
 
     match level {
         0 => {
-            // maximum supported level
-            if winnt_fix {
-                eax = 2;
-            }
-            else {
-                eax = 0x16;
-            }
+            // maximum supported level (default 0x16, overwritten to 2 as a workaround for Windows NT)
+            eax = cpuid_level as i32;
 
             ebx = 0x756E6547 | 0; // Genu
             edx = 0x49656E69 | 0; // ineI