arch-x86: Add extended state CPUID function

The extended state CPUID function is used to set the values of the XCR0
register as well as specify the size of storage for context switching
storage for x87 and AVX+. This function is iterative and therefore
requires (1) marking it as such in the hsaSignificantIndex function (2)
setting multiple sets of 4-tuples for the default CPUID values where the
last 4-tuple ends with all zeros.

Change-Id: Ib6a43925afb1cae75f61d8acff52a3cc26ce17c8

src/arch/x86/X86ISA.py

@@ -85,6 +85,20 @@ class X86ISA(BaseISA):
     ExtendedFeatures = VectorParam.UInt32(
         [0x00000000, 0x01800000, 0x00000000, 0x00000000], "feature flags"
     )
+    # 0000_000Dh - This uses ECX index, so the last entry must be all zeros
+    ExtendedState = VectorParam.UInt32(
+        [
+            0x00000000,
+            0x00000000,
+            0x00000000,
+            0x00000000,
+            0x00000000,
+            0x00000000,
+            0x00000000,
+            0x00000000,
+        ],
+        "extended state enumeration",
+    )
     # 8000_0001h
     FamilyModelSteppingBrandFeatures = VectorParam.UInt32(
         [0x00020F51, 0x00000405, 0xEBD3FBFF, 0x00020001],

src/arch/x86/cpuid.cc

@@ -146,6 +146,18 @@ X86CPUID::stringToRegister(const char *str)
 bool
 X86CPUID::hasSignificantIndex(uint32_t function)
 {
+    uint16_t family = bits(function, 31, 16);
+    uint16_t funcNum = bits(function, 15, 0);
+
+    if (family == 0x0000) {
+        switch (funcNum) {
+          case ExtendedState:
+            return true;
+          default:
+            return false;
+        }
+    }
+
     return false;
 }
 

src/arch/x86/cpuid.hh

@@ -52,6 +52,7 @@ enum StandardCpuidFunction
     MonitorMwait,
     ThermalPowerMgmt,
     ExtendedFeatures,
+    ExtendedState = 0xD,
     NumStandardCpuidFuncs
 };
 

src/arch/x86/isa.cc

@@ -157,6 +157,7 @@ ISA::ISA(const X86ISAParams &p)
     cpuid->addStandardFunc(FamilyModelStepping, p.FamilyModelStepping);
     cpuid->addStandardFunc(CacheParams, p.CacheParams);
     cpuid->addStandardFunc(ExtendedFeatures, p.ExtendedFeatures);
+    cpuid->addStandardFunc(ExtendedState, p.ExtendedState);
 
     cpuid->addExtendedFunc(FamilyModelSteppingBrandFeatures,
                           p.FamilyModelSteppingBrandFeatures);