arm, kvm: implement MuxingKvmGic

This device allows us to, when KVM support is detected and compiled in,
instantiate the same Gic device whether the actual simulation is with
KVM cores or simulated cores.  Checkpointing is not yet supported.

Change-Id: I67e4e0b6fb7ab5058e52c933f4f3d8e7ab24981e
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

src/arch/arm/kvm/KvmGic.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2015 ARM Limited
+# Copyright (c) 2015, 2017 ARM Limited
 # All rights reserved.
 #
 # The license below extends only to copyright in the software and shall
@@ -38,7 +38,7 @@
 from m5.params import *
 from m5.proxy import *
 
-from Gic import BaseGic
+from Gic import BaseGic, Pl390
 from KvmVM import KvmVM
 from System import System
 
@@ -52,3 +52,7 @@ class KvmGic(BaseGic):
 
     system = Param.System(Parent.any,
                           'System this interrupt controller belongs to')
+
+class MuxingKvmGic(Pl390):
+    type = 'MuxingKvmGic'
+    cxx_header = "arch/arm/kvm/gic.hh"

src/arch/arm/kvm/gic.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2016 ARM Limited
+ * Copyright (c) 2015-2017 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -35,14 +35,17 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * Authors: Andreas Sandberg
+ *          Curtis Dunham
  */
 
 #include "arch/arm/kvm/gic.hh"
 
 #include <linux/kvm.h>
 
+#include "arch/arm/kvm/base_cpu.hh"
 #include "debug/Interrupt.hh"
 #include "params/KvmGic.hh"
+#include "params/MuxingKvmGic.hh"
 
 KvmKernelGicV2::KvmKernelGicV2(KvmVM &_vm, Addr cpu_addr, Addr dist_addr,
                                unsigned it_lines)
@@ -183,3 +186,147 @@ KvmGicParams::create()
 {
     return new KvmGic(this);
 }
+
+
+MuxingKvmGic::MuxingKvmGic(const MuxingKvmGicParams *p)
+    : Pl390(p),
+      system(*p->system),
+      kernelGic(nullptr),
+      usingKvm(false)
+{
+    if (auto vm = system.getKvmVM()) {
+        kernelGic = new KvmKernelGicV2(*vm, p->cpu_addr, p->dist_addr,
+                                       p->it_lines);
+    }
+}
+
+MuxingKvmGic::~MuxingKvmGic()
+{
+}
+
+void
+MuxingKvmGic::startup()
+{
+    usingKvm = (kernelGic != nullptr) && validKvmEnvironment();
+}
+
+void
+MuxingKvmGic::drainResume()
+{
+    bool use_kvm = (kernelGic != nullptr) && validKvmEnvironment();
+    if (use_kvm != usingKvm) {
+        if (use_kvm) // from simulation to KVM emulation
+            fromPl390ToKvm();
+        else // from KVM emulation to simulation
+            fromKvmToPl390();
+
+        usingKvm = use_kvm;
+    }
+}
+
+void
+MuxingKvmGic::serialize(CheckpointOut &cp) const
+{
+    if (!usingKvm)
+        return Pl390::serialize(cp);
+
+    panic("Checkpointing unsupported\n");
+}
+
+void
+MuxingKvmGic::unserialize(CheckpointIn &cp)
+{
+    if (!usingKvm)
+        return Pl390::unserialize(cp);
+
+    panic("Checkpointing unsupported\n");
+}
+
+Tick
+MuxingKvmGic::read(PacketPtr pkt)
+{
+    if (!usingKvm)
+        return Pl390::read(pkt);
+
+    panic("MuxingKvmGic: PIO from gem5 is currently unsupported\n");
+}
+
+Tick
+MuxingKvmGic::write(PacketPtr pkt)
+{
+    if (!usingKvm)
+        return Pl390::write(pkt);
+
+    panic("MuxingKvmGic: PIO from gem5 is currently unsupported\n");
+}
+
+void
+MuxingKvmGic::sendInt(uint32_t num)
+{
+    if (!usingKvm)
+        return Pl390::sendInt(num);
+
+    DPRINTF(Interrupt, "Set SPI %d\n", num);
+    kernelGic->setSPI(num);
+}
+
+void
+MuxingKvmGic::clearInt(uint32_t num)
+{
+    if (!usingKvm)
+        return Pl390::clearInt(num);
+
+    DPRINTF(Interrupt, "Clear SPI %d\n", num);
+    kernelGic->clearSPI(num);
+}
+
+void
+MuxingKvmGic::sendPPInt(uint32_t num, uint32_t cpu)
+{
+    if (!usingKvm)
+        return Pl390::sendPPInt(num, cpu);
+    DPRINTF(Interrupt, "Set PPI %d:%d\n", cpu, num);
+    kernelGic->setPPI(cpu, num);
+}
+
+void
+MuxingKvmGic::clearPPInt(uint32_t num, uint32_t cpu)
+{
+    if (!usingKvm)
+        return Pl390::clearPPInt(num, cpu);
+
+    DPRINTF(Interrupt, "Clear PPI %d:%d\n", cpu, num);
+    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::fromPl390ToKvm()
+{
+    panic("Gic multiplexing not implemented.\n");
+}
+
+void
+MuxingKvmGic::fromKvmToPl390()
+{
+    panic("Gic multiplexing not implemented.\n");
+}
+
+MuxingKvmGic *
+MuxingKvmGicParams::create()
+{
+    return new MuxingKvmGic(this);
+}

src/arch/arm/kvm/gic.hh

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2016 ARM Limited
+ * Copyright (c) 2015-2017 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -35,6 +35,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * Authors: Andreas Sandberg
+ *          Curtis Dunham
  */
 
 #ifndef __ARCH_ARM_KVM_GIC_HH__
@@ -44,6 +45,7 @@
 #include "cpu/kvm/device.hh"
 #include "cpu/kvm/vm.hh"
 #include "dev/arm/base_gic.hh"
+#include "dev/arm/gic_pl390.hh"
 #include "dev/platform.hh"
 
 /**
@@ -205,4 +207,47 @@ class KvmGic : public BaseGic
     const AddrRangeList addrRanges;
 };
 
+struct MuxingKvmGicParams;
+
+class MuxingKvmGic : public Pl390
+{
+  public: // SimObject / Serializable / Drainable
+    MuxingKvmGic(const MuxingKvmGicParams *p);
+    ~MuxingKvmGic();
+
+    void startup() override;
+    void drainResume() override;
+
+    void serialize(CheckpointOut &cp) const override;
+    void unserialize(CheckpointIn &cp) override;
+
+  public: // PioDevice
+    Tick read(PacketPtr pkt) override;
+    Tick write(PacketPtr pkt) override;
+
+  public: // Pl390
+    void sendInt(uint32_t num) override;
+    void clearInt(uint32_t num) override;
+
+    void sendPPInt(uint32_t num, uint32_t cpu) override;
+    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;
+
+    /** Kernel GIC device */
+    KvmKernelGicV2 *kernelGic;
+
+  private:
+    bool usingKvm;
+
+    /** Multiplexing implementation: state transfer functions */
+    void fromPl390ToKvm();
+    void fromKvmToPl390();
+};
+
 #endif // __ARCH_ARM_KVM_GIC_HH__