text: /*
   * Copyright 2007 The Hewlett-Packard Development Company
   *
   * The license below extends only to copyright in the software and shall
   * not be construed as granting a license to any other intellectual
   * property including but not limited to intellectual property relating
   * to a hardware implementation of the functionality of the software
   * licensed hereunder.  You may use the software subject to the license
   * terms below provided that you ensure that this notice is replicated
   * unmodified and in its entirety in all distributions of the software,
   * modified or unmodified, in source code or in binary form.
   *
   * Copyright 2020 Google Inc.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met: redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer;
   * redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution;
   * neither the name of the copyright holders nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "arch/x86/linux/se_workload.hh"
  
  #include <sys/syscall.h>
  
  #include "arch/x86/linux/linux.hh"
  #include "arch/x86/page_size.hh"
  #include "arch/x86/process.hh"
  #include "arch/x86/regs/int.hh"
  #include "arch/x86/se_workload.hh"
  #include "base/trace.hh"
  #include "cpu/thread_context.hh"
  #include "kern/linux/linux.hh"
  #include "mem/se_translating_port_proxy.hh"
  #include "sim/process.hh"
  #include "sim/syscall_desc.hh"
  #include "sim/syscall_emul.hh"
  
  namespace gem5
  {
  
  namespace
  {
  
  class LinuxLoader : public Process::Loader
  {
    public:
      Process *
      load(const ProcessParams &params, loader::ObjectFile *obj_file)
      {
          auto arch = obj_file->getArch();
          auto opsys = obj_file->getOpSys();
  
          if (arch != loader::X86_64 && arch != loader::I386)
              return nullptr;
  
          if (opsys == loader::UnknownOpSys) {
              warn("Unknown operating system; assuming Linux.");
              opsys = loader::Linux;
          }
  
          if (opsys != loader::Linux)
              return nullptr;
  
          if (arch == loader::X86_64)
              return new X86ISA::X86_64Process(params, obj_file);
          else
              return new X86ISA::I386Process(params, obj_file);
      }
  };
  
  LinuxLoader linuxLoader;
  
  } // anonymous namespace
  
  namespace X86ISA
  {
  
  EmuLinux::EmuLinux(const Params &p) : SEWorkload(p, PageShift)
  {}
  
  const std::vector<IntRegIndex> EmuLinux::SyscallABI64::ArgumentRegs = {
      INTREG_RDI, INTREG_RSI, INTREG_RDX, INTREG_R10W, INTREG_R8W, INTREG_R9W
  };
  
  const std::vector<IntRegIndex> EmuLinux::SyscallABI32::ArgumentRegs = {
      INTREG_EBX, INTREG_ECX, INTREG_EDX, INTREG_ESI, INTREG_EDI, INTREG_EBP
  };
  
  void
  EmuLinux::syscall(ThreadContext *tc)
  {
      Process *process = tc->getProcessPtr();
      // Call the syscall function in the base Process class to update stats.
      // This will move into the base SEWorkload function at some point.
      process->Process::syscall(tc);
  
      RegVal rax = tc->readIntReg(INTREG_RAX);
      if (dynamic_cast<X86_64Process *>(process)) {
          syscallDescs64.get(rax)->doSyscall(tc);
      } else if (auto *proc32 = dynamic_cast<I386Process *>(process)) {
          PCState pc = tc->pcState().as<PCState>();
          Addr eip = pc.pc();
          const auto &vsyscall = proc32->getVSyscallPage();
          if (eip >= vsyscall.base && eip < vsyscall.base + vsyscall.size) {
              pc.set(vsyscall.base + vsyscall.vsysexitOffset);
              tc->pcState(pc);
          }
          syscallDescs32.get(rax)->doSyscall(tc);
      } else {
          panic("Unrecognized process type.");
      }
  }
  
  void
  EmuLinux::event(ThreadContext *tc)
  {
      Process *process = tc->getProcessPtr();
      Addr pc = tc->pcState().instAddr();
  
      if (process->kvmInSE) {
          Addr pc_page = mbits(pc, 63, 12);
          if (pc_page == syscallCodeVirtAddr) {
              syscall(tc);
              return;
          } else if (pc_page == PFHandlerVirtAddr) {
              pageFault(tc);
              return;
          }
      }
      warn("Unexpected workload event at pc %#x.", pc);
  }
  
  void
  EmuLinux::pageFault(ThreadContext *tc)
  {
      Process *p = tc->getProcessPtr();
      if (!p->fixupFault(tc->readMiscReg(MISCREG_CR2))) {
          SETranslatingPortProxy proxy(tc);
          // at this point we should have 6 values on the interrupt stack
          int size = 6;
          uint64_t is[size];
          // reading the interrupt handler stack
          proxy.readBlob(ISTVirtAddr + PageBytes - size * sizeof(uint64_t),
                         &is, sizeof(is));
          panic("Page fault at addr %#x\n\tInterrupt handler stack:\n"
                  "\tss: %#x\n"
                  "\trsp: %#x\n"
                  "\trflags: %#x\n"
                  "\tcs: %#x\n"
                  "\trip: %#x\n"
                  "\terr_code: %#x\n",
                  tc->readMiscReg(MISCREG_CR2),
                  is[5], is[4], is[3], is[2], is[1], is[0]);
     }
  }
  
  } // namespace X86ISA
  } // namespace gem5
  