fastmodel: skip vector registers update in remote gdb

iris::ThreadContext doesn't implement the write interface for vector
registers. Skip that part in fastmodel remote_gdb to make updating
common registers work at least.

Change-Id: Ifa071f5dff4bdeee7361ae824b4b76e0b2805460
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/69177
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/arch/arm/fastmodel/remote_gdb.cc

@@ -27,13 +27,42 @@
 #include "arch/arm/fastmodel/remote_gdb.hh"
 
 #include "arch/arm/fastmodel/iris/thread_context.hh"
+#include "arch/arm/utility.hh"
+#include "base/trace.hh"
+#include "debug/GDBAcc.hh"
 
 namespace gem5 {
 
+using namespace ArmISA;
+
 namespace fastmodel {
 
+void
+FastmodelRemoteGDB::AArch64GdbRegCache::setRegs(ThreadContext *context) const
+{
+    DPRINTF(GDBAcc, "setRegs in remotegdb \n");
+
+    for (int i = 0; i < 31; ++i)
+        context->setReg(int_reg::x(i), r.x[i]);
+    auto pc_state = context->pcState().as<PCState>();
+    pc_state.set(r.pc);
+    context->pcState(pc_state);
+    context->setMiscRegNoEffect(MISCREG_CPSR, r.cpsr);
+    // Update the stack pointer. This should be done after
+    // updating CPSR/PSTATE since that might affect how SPX gets
+    // mapped.
+    context->setReg(int_reg::Spx, r.spx);
+
+    // Remove the vector registers update in FastmodelRemoteGDB since it's not
+    // implemented in iris::ThreadContext.
+    warn("Skip update vector registers in remotegdb\n");
+
+    context->setMiscRegNoEffect(MISCREG_FPSR, r.fpsr);
+    context->setMiscRegNoEffect(MISCREG_FPCR, r.fpcr);
+}
+
 FastmodelRemoteGDB::FastmodelRemoteGDB(System *_system, int port)
-    : gem5::ArmISA::RemoteGDB(_system, port)
+    : gem5::ArmISA::RemoteGDB(_system, port), regCache64(this)
 {
 }
 
@@ -57,5 +86,14 @@ FastmodelRemoteGDB::writeBlob(Addr vaddr, size_t size, const char *data)
     return true;
 }
 
+BaseGdbRegCache*
+FastmodelRemoteGDB::gdbRegs()
+{
+    if (inAArch64(context()))
+        return &regCache64;
+    else
+        return &regCache32;
+}
+
 }  // namespace fastmodel
 }  // namespace gem5

src/arch/arm/fastmodel/remote_gdb.hh

@@ -36,14 +36,24 @@ namespace gem5
 namespace fastmodel
 {
 
-class FastmodelRemoteGDB : public gem5::ArmISA::RemoteGDB
+class FastmodelRemoteGDB : public ArmISA::RemoteGDB
 {
   public:
     FastmodelRemoteGDB(System *_system, int port);
 
-  private:
+  protected:
+    class AArch64GdbRegCache : public ArmISA::RemoteGDB::AArch64GdbRegCache
+    {
+      using ArmISA::RemoteGDB::AArch64GdbRegCache::AArch64GdbRegCache;
+      public:
+        void setRegs(ThreadContext*) const override;
+    };
+
     bool readBlob(Addr vaddr, size_t size, char *data) override;
     bool writeBlob(Addr vaddr, size_t size, const char *data) override;
+    BaseGdbRegCache* gdbRegs() override;
+
+    AArch64GdbRegCache regCache64;
 };
 
 }  // namespace fastmodel

src/arch/arm/remote_gdb.hh

@@ -68,7 +68,7 @@ class RemoteGDB : public BaseRemoteGDB
     class AArch32GdbRegCache : public BaseGdbRegCache
     {
       using BaseGdbRegCache::BaseGdbRegCache;
-      private:
+      protected:
         struct GEM5_PACKED
         {
           uint32_t gpr[16];
@@ -77,12 +77,12 @@ class RemoteGDB : public BaseRemoteGDB
           uint32_t fpscr;
         } r;
       public:
-        char *data() const { return (char *)&r; }
-        size_t size() const { return sizeof(r); }
-        void getRegs(ThreadContext*);
-        void setRegs(ThreadContext*) const;
+        char *data() const override { return (char *)&r; }
+        size_t size() const override { return sizeof(r); }
+        void getRegs(ThreadContext*) override;
+        void setRegs(ThreadContext*) const override;
         const std::string
-        name() const
+        name() const override
         {
             return gdb->name() + ".AArch32GdbRegCache";
         }
@@ -91,7 +91,7 @@ class RemoteGDB : public BaseRemoteGDB
     class AArch64GdbRegCache : public BaseGdbRegCache
     {
       using BaseGdbRegCache::BaseGdbRegCache;
-      private:
+      protected:
         struct GEM5_PACKED
         {
           uint64_t x[31];
@@ -103,12 +103,12 @@ class RemoteGDB : public BaseRemoteGDB
           uint32_t fpcr;
         } r;
       public:
-        char *data() const { return (char *)&r; }
-        size_t size() const { return sizeof(r); }
-        void getRegs(ThreadContext*);
-        void setRegs(ThreadContext*) const;
+        char *data() const override { return (char *)&r; }
+        size_t size() const override { return sizeof(r); }
+        void getRegs(ThreadContext*) override;
+        void setRegs(ThreadContext*) const override;
         const std::string
-        name() const
+        name() const override
         {
             return gdb->name() + ".AArch64GdbRegCache";
         }

src/base/remote_gdb.hh

@@ -188,7 +188,7 @@ class BaseRemoteGDB
             return nullptr;
     }
 
-  private:
+  protected:
     /*
      * Connection to the external GDB.
      */