kvm: move Kvm check from ARM Kvm GIC to System

The check was nearly completely generic anyway,
with the exception of the Kvm CPU type.

This will make it easier for other parts of the
codebase to do similar checks.

Change-Id: Ibfdd3d65e9e6cc3041b53b73adfabee1999283da
Reviewed-on: https://gem5-review.googlesource.com/3540
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

src/arch/arm/kvm/gic.cc

@@ -189,7 +189,7 @@ void
 MuxingKvmGic::startup()
 {
     Pl390::startup();
-    usingKvm = (kernelGic != nullptr) && validKvmEnvironment();
+    usingKvm = (kernelGic != nullptr) && system.validKvmEnvironment();
     if (usingKvm)
         fromPl390ToKvm();
 }
@@ -206,7 +206,7 @@ void
 MuxingKvmGic::drainResume()
 {
     Pl390::drainResume();
-    bool use_kvm = (kernelGic != nullptr) && validKvmEnvironment();
+    bool use_kvm = (kernelGic != nullptr) && system.validKvmEnvironment();
     if (use_kvm != usingKvm) {
         // Should only occur due to CPU switches
         if (use_kvm) // from simulation to KVM emulation
@@ -287,20 +287,6 @@ MuxingKvmGic::clearPPInt(uint32_t num, uint32_t cpu)
     kernelGic->clearPPI(cpu, num);
 }
 
-bool
-MuxingKvmGic::validKvmEnvironment() const
-{
-    if (system.threadContexts.empty())
-        return false;
-
-    for (auto tc : system.threadContexts) {
-        if (dynamic_cast<BaseArmKvmCPU*>(tc->getCpuPtr()) == nullptr) {
-            return false;
-        }
-    }
-    return true;
-}
-
 void
 MuxingKvmGic::copyDistRegister(BaseGicRegisters* from, BaseGicRegisters* to,
                                ContextID ctx, Addr daddr)

src/arch/arm/kvm/gic.hh

@@ -195,9 +195,6 @@ class MuxingKvmGic : public Pl390
     void clearPPInt(uint32_t num, uint32_t cpu) override;
 
   protected:
-    /** Verify gem5 configuration will support KVM emulation */
-    bool validKvmEnvironment() const;
-
     /** System this interrupt controller belongs to */
     System &system;
 

src/sim/system.cc

@@ -55,6 +55,7 @@
 #include "base/trace.hh"
 #include "config/use_kvm.hh"
 #if USE_KVM
+#include "cpu/kvm/base.hh"
 #include "cpu/kvm/vm.hh"
 #endif
 #include "cpu/thread_context.hh"
@@ -335,6 +336,24 @@ System::replaceThreadContext(ThreadContext *tc, ContextID context_id)
         remoteGDB[context_id]->replaceThreadContext(tc);
 }
 
+bool
+System::validKvmEnvironment() const
+{
+#if USE_KVM
+    if (threadContexts.empty())
+        return false;
+
+    for (auto tc : threadContexts) {
+        if (dynamic_cast<BaseKvmCPU*>(tc->getCpuPtr()) == nullptr) {
+            return false;
+        }
+    }
+    return true;
+#else
+    return false;
+#endif
+}
+
 Addr
 System::allocPhysPages(int npages)
 {

src/sim/system.hh

@@ -262,6 +262,9 @@ class System : public MemObject
         return kvmVM;
     }
 
+    /** Verify gem5 configuration will support KVM emulation */
+    bool validKvmEnvironment() const;
+
     /** Get a pointer to access the physical memory of the system */
     PhysicalMemory& getPhysMem() { return physmem; }