rng.hh

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/*
 * Copyright (c) 2022  Institute of Computing Technology, Chinese Academy
 *                     of Sciences
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#ifndef __DEV_VIRTIO_RNG_HH__
#define __DEV_VIRTIO_RNG_HH__
 
#include <random>
 
#include "base/compiler.hh"
#include "dev/virtio/base.hh"
 
namespace gem5
{
 
struct VirtIORngParams;
 
class VirtIORng : public VirtIODeviceBase
{
  public:
    typedef VirtIORngParams Params;
    VirtIORng(const Params &params);
    virtual ~VirtIORng();
 
    void readConfig(PacketPtr pkt, Addr cfgOffset);
 
  protected:
    static const DeviceId ID_RNG = 0x04;
 
  protected:
    class RngQueue
        : public VirtQueue
    {
      public:
        RngQueue(PortProxy &proxy, ByteOrder bo,
                uint16_t size, const std::string &rng_file_path,
                VirtIORng &_parent);
        virtual ~RngQueue() {}
 
        void onNotify() { trySend(); }
 
        void trySend();
 
        std::string name() const { return parent.name() + ".qRecv"; }
 
      protected:
        VirtIORng &parent;
      private:
        // system's special file for generating random number
        int rng_fd;
        // fallback random number generator
        std::random_device rd_device;
        std::uniform_int_distribution<int> dist;
    };
    RngQueue qReq;
};
 
} // namespace gem5
 
#endif // __DEV_VIRTIO_RNG_HH__