FEXCore: Support passing process pid to the backend

FEXCore/include/FEXCore/Core/HostFeatures.h

@@ -84,5 +84,9 @@ struct HostFeatures {
   // MIDR information
   // Also used for determining number of CPU cores for CPUID
   fextl::vector<uint32_t> CPUMIDRs;
+
+  // The Linux PID of this process. Useful for punching through perf-top information.
+  uint32_t ProcessPID {};
+  uint32_t pad2 {};
 };
 } // namespace FEXCore

Source/Common/HostFeatures.cpp

@@ -633,6 +633,7 @@ FEXCore::HostFeatures FetchHostFeatures() {
 
   HostFeatures.SupportsCPUIndexInTPIDRRO = false;
   HostFeatures.HostType = FEXCore::HostFeatures::HostTypeEnum::Linux;
+  HostFeatures.ProcessPID = ::getpid();
   return HostFeatures;
 }
 } // namespace FEX

Source/Tools/FEXOfflineCompiler/Main.cpp

@@ -415,7 +415,7 @@ static std::optional<std::string> GenerateSingleCache(FEXCore::ExecutableFileInf
   const auto NtDll = GetModuleHandleW(L"ntdll.dll");
   const bool IsWine = !!GetProcAddress(NtDll, "wine_get_version");
   auto HostFeatures = FEX::Windows::CPUFeatures::FetchHostFeatures(
-    IsWine, Is64Bit ? FEXCore::HostFeatures::HostTypeEnum::Arm64ec : FEXCore::HostFeatures::HostTypeEnum::Wow64);
+    IsWine, Is64Bit ? FEXCore::HostFeatures::HostTypeEnum::Arm64ec : FEXCore::HostFeatures::HostTypeEnum::Wow64, 0);
 #endif
 
   auto CTX = FEXCore::Context::Context::CreateNewContext(HostFeatures);

Source/Windows/ARM64EC/Module.cpp

@@ -612,7 +612,8 @@ NTSTATUS ProcessInit() {
   }
 
   {
-    auto HostFeatures = FEX::Windows::CPUFeatures::FetchHostFeatures(IsWine, FEXCore::HostFeatures::HostTypeEnum::Arm64ec);
+    auto HostFeatures =
+      FEX::Windows::CPUFeatures::FetchHostFeatures(IsWine, FEXCore::HostFeatures::HostTypeEnum::Arm64ec, FEX::Windows::UnixLib::GetPID());
     CTX = FEXCore::Context::Context::CreateNewContext(HostFeatures);
   }
 

Source/Windows/Common/CPUFeatures.cpp

@@ -56,7 +56,7 @@ public:
   }
 };
 
-FEXCore::HostFeatures CPUFeatures::FetchHostFeatures(bool IsWine, FEXCore::HostFeatures::HostTypeEnum HostType) {
+FEXCore::HostFeatures CPUFeatures::FetchHostFeatures(bool IsWine, FEXCore::HostFeatures::HostTypeEnum HostType, uint32_t ProcessPID) {
   HKEY Key = OpenProcessorKey(0);
   if (!Key) {
     ERROR_AND_DIE_FMT("Couldn't detect CPU features");
@@ -84,6 +84,7 @@ FEXCore::HostFeatures CPUFeatures::FetchHostFeatures(bool IsWine, FEXCore::HostF
   HostFeatures.SupportsCPUIndexInTPIDRRO = !IsWine;
 
   HostFeatures.HostType = HostType;
+  HostFeatures.ProcessPID = ProcessPID;
 
   if (HostType == FEXCore::HostFeatures::HostTypeEnum::Wow64) {
     // AVX is unsupported for WOW64

Source/Windows/Common/CPUFeatures.h

@@ -16,7 +16,7 @@ class Context;
 namespace FEX::Windows {
 class CPUFeatures {
 public:
-  static FEXCore::HostFeatures FetchHostFeatures(bool IsWine, FEXCore::HostFeatures::HostTypeEnum HostType);
+  static FEXCore::HostFeatures FetchHostFeatures(bool IsWine, FEXCore::HostFeatures::HostTypeEnum HostType, uint32_t ProcessPID);
 
   CPUFeatures(FEXCore::Context::Context& CTX);
 

Source/Windows/WOW64/Module.cpp

@@ -527,7 +527,8 @@ void BTCpuProcessInit() {
   }
 
   {
-    auto HostFeatures = FEX::Windows::CPUFeatures::FetchHostFeatures(IsWine, FEXCore::HostFeatures::HostTypeEnum::Wow64);
+    auto HostFeatures =
+      FEX::Windows::CPUFeatures::FetchHostFeatures(IsWine, FEXCore::HostFeatures::HostTypeEnum::Wow64, FEX::Windows::UnixLib::GetPID());
     CTX = FEXCore::Context::Context::CreateNewContext(HostFeatures);
   }